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JULY 1 999 

ISSN 0020-1324-RECACP 


Who Should Perform Intubation? 

Managing the Artificial Airway 

Difficult Intubation 

Extubation and Consequences of 

Indications and Timing of Tracheotomy 



Complications of Endotracheal Intubation 
and Tracheostomy 

Communication and Swallowing 


Conference Summary 

, — . . 1 






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Richard D Branson RRT 
Charles G Durbin Jr MD 


Who Should Perform Intubation? 

by Michael J Bishop — Seattle, Washington 

Managing the Artificial Airway 
by Dean R Hess — Boston, Massachusetts 

Prediction of a Difficult Intubation: Methods for Successful Intubation 
by Charles B Watson — Bridgeport, Connecticut 

Extubation and the Consequences of Reintubation 
by Robert S Campbell — Cincinnati, Ohio 

Tracheotomy: Indications and Timing 
by John E Heffiier — Charleston, South Carolina 


by James F Reibel — Charlottesville, Virginia 

Complications of Endotracheal Intubation and Tracheotomy 
by John L Stauffer — Hershey, Pennsylvania 

The Effects of Tracheostomy Tube Placement on Communication 

and Swallowing 

by Maxine K Orringer — Pittsburgh, Pennsylvania 

Decannulation: How and Where 

by James F Reibel — Charlottesville, Virginia 

Artificial Airways: Conference Summary 
by John E Hejfner — Charleston, South Carolina 


Mechanical Ventilation: Physiological and Clinical Applications 
reviewed by Catherine Sassoon — Long Beach, California 

Sleep Disorders Sourcebook 

reviewed by Vishesh Kapur — Seattle, Washington 





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Abstracts from 
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Advertisers Index 
& Help Lines 




of Events 


Preparation Guide 


New Products 
& Services 



Professional Ethics: A Guide for Rehabilitation Professionals 

reviewed by Ronald G Beckett — Hamden, Connecticut 7 

Introductory Medical Statistics a e n 

reviewed by David Au — Seattle, Washington w 









A Monthly Science Journal 
Established in 1956 

The Official Journal of the 

American Association for 

Respiratory Care 

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A Monthly Science Journal 
Established in 1956 

The Official Journal of the 

American Association for 

Respiratory Care 

David J Pierson MD 
Harborview Medical Center 
University of Washington 
Seattle, Washington 


Richard D Branson RRT 

University of Cincinnati 
Cincinnati, Ohio 

Charles G Durbin Jr MD 

University of Virginia 
Charlottesville, Virginia 


Dean R Hess PhD RRT FAARC 

Massachusetts General Hospital 
Harvard University 
Boston, Massachusetts 

James K Stoller MD 

The Cleveland Clinic Foundation 

Cleveland, Ohio 

Thomas A Barnes EdD RRT 

Northeastern University 
Boston, Massachusetts 

Michael J Bishop MD 

University of Washington 
Seattle, Washington 

Bartolome R Celli MD 

Tufts University 
Boston, Massachusetts 

Robert L Chatbum RRT 

University Hospitals of Cleveland 
Case Western Reserve University 
Cleveland, Ohio 

Luciano Gattinoni MD 

University of Milan 
Milan, Italy 

John E Heffner MD 

Medical University of South Carolina 
Charleston, South Carolina 

Mark J Heulitt MD 

University of Arkansas 
Little Rock, Arkansas 


Leonard D Hudson MD 

University of Washington 
Seattle, Washington 

Robert M Kacmarek PhD RRT 


Massachusetts General Hospital 

Harvard University 

Boston, Massachusetts 

Toshihiko Koga MD 

Koga Hospital 
Kurume, Japan 

Marin H Kollef MD 
Washington University 
St Louis, Missouri 

Patrick Leger MD 
Clinique Medicale Edouard Rist 
Paris, France 

Neil R Maclntyre MD FAARC 

Duke University 
Durham, North Carolina 

John J Marini MD 

University of Minnesota 
St Paul, Minnesota 

Shelley C Mishoe PhD RRT 

Medical College of Georgia 
Augusta, Georgia 

Joseph L Rau PhD RRT 

Georgia State University 
Atlanta. Georgia 

Catherine SH Sassoon MD 

University of California Irvine 
Long Beach, California 

Arthur S Slutsky MD 

University of Toronto 
Toronto, Ontario, Canada 

Martin J Tobin MD 

Loyola University 
Maywood, Illinois 


Gordon D Rubenfeld MD 

University of Washington 
Seattle. Washington 

Hugh S Mathewson MD 
Joseph L Rau PhD RRT 
Drug Capsule 

Charles G Irvin PhD 

Gregg L Ruppel MEd RRT RPFT FAARC 

PFT Comer 

Richard D Branson RRT 
Robert S Campbell RRT 
Kittredge 's Corner 

Jon Nilsestuen PhD RRT FAARC 
Ken Hargett RRT 
Graphics Corner 

Patricia Ann Doorley MS RRT 
Charles G Durbin Jr MD 
Test Your Radiologic Skill 


Summaries of Pertinent Articles in Other Journals 

Editorials, Commentaries, and Reviews to Note 

The Trials and Tribulations of Clinical Practice Guidelines — Cook D, Giacomini M. JAMA 
1 999 May 26;28 1 (20): 1 950- 1 95 1 . 

Respiratory Nursing Society Position Statement on Development of Non-Chlorofluorocar- 
bon Metered Dose Inhalers— Gift A. Heart Lung 1999 May-Jun;28(3);224-225. 

Guidelines for Intensive Care Unit Admission, Discharge, and Triage — Task Force of the 
American College of Critical Care Medicine. Society of Critical Care Medicine. Crit Care Med 
1999 Mar;27(3):633-638. 

Guidelines for Developing Admission and Discharge Policies for the Pediatric Intensive 
Care Unit — American Academy of Pediatrics. Committee on Hospital Care and Section of 
Critical Care. Society of Critical Care Medicine. Pediatric Section Admission Criteria Task Force. 
Pediatrics 1999 Apr;103(4 Pt l):840-842. 

Practice Parameters for Hemodynamic Support of Sepsis in Adult Patients in Sepsis — Task 
Force of the American College of Critical Care Medicine. Society of Critical Care Medicine. Crit 
Care Med 1999 Mar;27(3):639-660. 

Guidelines for Developing Admission and Discharge Policies for the Pediatric Intensive 
Care Unit — Pediatric Section Task Force on Admission and Discharge Criteria, Society of 
Critical Care Medicine in conjunction with the American College of Critical Care Medicine and 
the Committee on Hospital Care of the American Academy of Pediatrics. Crit Care Med 1999 


Recent Advances in the Pharmacotherapy of 
Smoking — Hughes JR, Goldstein MG, Hurt 
RD, Shiffman S. JAMA 1999;281(l);72. 

Since the 1996 publication of guidelines on 
smoking cessation from the Agency for Health 
Care Policy and Research and the American 
Psychiatric Association, several new treatments 
have become available, including nicotine na- 
sal spray, nicotine inhaler, and bupropion hy- 
drochloride. In addition, nicotine gum and patch 
have become available over-the-counter. This 
article reviews the published literature and US 
Food and Drug Administration and pharmaceu- 
tical company reports on these therapies. Based 
on this review, clinical logic, and experience, 
we conclude that pharmacotherapy should be 
made available to all smokers. All currently 
available therapies appear to be equally effica- 
cious, approximately doubling the quit rate com- 
pared with placebo. Concomitant behavioral or 
supportive therapy increases quit rates and 
should be encouraged but not required. Com- 
bining patch with gum or patch with bupropion 
may increase the quit rate compared with any 
single treatment. Because patient characteris- 
tics predictive of success with a particular ther- 

apy are not yet known, the best treatment choice 
for an individual patient should be guided by 
the patient's past experience and preference and 
the product's adverse effect profile. 

Trends in Infectious Disease Mortality in the 
United States During the 20th Century— 

Arm.strong GL, Conn LA, Pinner RW. JAMA 

CONTEXT: Recent in infectious dis- 
ease mortality and concern about emerging in- 
fections warrant an examination of longer-term 
trends. OBJECTIVE: To describe trends in in- 
fectious di.sease mortality in the United States 
during the 20th century. DESIGN AND SET- 
TING: De.scriptive study of infectious disease 
mortality in the United States. Deaths due to 
infectious diseases from 1900 to 1996 were tal- 
lied by using mortality tables. Trends in age- 
specific infectious disease mortality were ex- 
amined by using age-specific death rates for 9 
common infectious causes of death. SUB- 
JECTS: Persons who died in the United States 
between 1900 and 1996. MAIN OUTCOME 
MEASURES: Crude and age-adjusted mortal- 
ity rates. RESULTS; Infectious di.sease mortal- 

ity declined during the first 8 decades of the 
20th century from 797 deaths per 100000 in 
1900 to 36 deaths per 100000 in 1980. From 
1981 to 1995, the mortality rate increased to a 
peak of 63 deaths per 100000 in 1995 and de- 
clined to 59 deaths per 100000 in 1996. The 
decline was interrupted by a sharp spike in mor- 
tality caused by the 1918 influenza epidemic. 
From 1938 to 1952, the decline was particu- 
larly rapid, with mortality decreasing 8.2% per 
year. Pneumonia and influenza were responsi- 
ble for the largest number of infectious disease 
deaths throughout the century. Tuberculosis 
caused almost as many deaths as pneumonia 
and influenza early in the century, but tubercu- 
losis mortality dropped off sharply after 1945. 
Infectious disease mortality increased in the 
1980s and early 1990s in persons aged 25 years 
and older and was mainly due to the emergence 
of the acquired immunodeficiency syndrome 
(AIDS) in 25- to 64-year-olds and, to a lesser 
degree, to increases in pneumonia and influ- 
enza deaths among persons aged 65 years and 
older. There was considerable year-to-year vari- 
ability in infectious disease mortality, especially 
for the youngest and oldest age groups. CON- 
CLUSIONS: Although most of the 20th cen- 


Respiratory Care • July 1999 Vol 43 No 7 

ijour oriificiol oiriiiflijs shills 


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Outlines the basic concepts of ventilator classification and a 
mathematical model of the respiratory system that provides the 
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specific criteria for determining whether a ventilator primarily 
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Classification of Mechanical Ventilators II 

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tury has been marked by declining infectious 
disease mortality, substantial year-to-year vari- 
ation as well as recent increases emphasize the 
dynamic nature of infectious diseases and the 
need for preparedness to address them. 

Quality End-of-Life Care: Patients' Perspec- 
tives — Singer PA, Martin DK, Kelner M. JAMA 

CONTEXT: Quality end-of-life care is increas- 
ingly recognized as an ethical obligation of 
health care providers, both clinicians and orga- 
nizations. However, this concept has not been 
examined from the perspective of patients. OB- 
JECTIVE: To identify and describe elements of 
quality end-of-life care from the patient's per- 
spective. DESIGN: Qualitative study using in- 
depth, open-ended, face-to-face interviews and 
content analysis. SETTING: Toronto, Ontario. 
PARTICIPANTS: A total of 126 participants 
from 3 patient groups: dialysis patients (n = 
48), people with human immunodeficiency vi- 
rus infection (n = 40), and residents of a long- 
term care facility (n = 38). OUTCOME MEA- 
SURES: Participants' views on end-of-life 
issues. RESULTS: Participants identified 5 do- 
mains of quality end-of-life care: receiving ad- 
equate pain and symptom management, avoid- 
ing inappropriate prolongation of dying, 
achieving a sense of control, relieving burden, 
and strengthening relationships with loved ones. 
CONCLUSION: These domains, which char- 
acterize patients' perspectives on end-of-life 
care, can serve as focal points for improving the 
quality of end-of-life care. 

Leuliotricne-Receptor Antagonists — Lip- 
worth BJ. Lancet 1999;353(9146):57. 

Leukotriene-receptor antagonists are the first 
novel class of antiasthma drugs to become avail- 
able over the past three decades. They have an 
unique profile in that they are a hybrid of an 
anti-inflammatory and bronchodilator drug, and 
they can be taken as a tablet once or twice 
daily. The published data with leukotriene-re- 
ceptor antagonists such as montelukast or 
zafirlukast show good antiasthmatic activity 
over a wide spectrum of asthma severity either 
as monotherapy or with inhaled steroids. An- 
other potential spin-off of leukotriene-receptor 
antagonists is that they also seem to be effec- 
tive in treating allergic rhinitis, which commonly 
coexists in patients with asthma. Here I over- 
view the clinical pharmacology of leukotriene 
antagonists and appraise the published data from 
clinical trials, and look at the appropriate posi- 
tion of these agents in asthma management 

Lung Function in Infants with Wheezing and 
Gastroesophageal Reflux — Sheikh S, Gold- 
smith LJ, Howell L, Hamlyn J, Eid N. Pediatr 
Pulmonol 1999 Apr:27(4):236-241. 

Eighty-four otherwise healthy infants with daily 
wheezing underwent infant pulmonary function 
tests (IPFTs) and 24-h esophageal pH probe 
studies. Fifty-four (64%) infants had positive 
pH probe studies, and 30 infants had negative 
pH probe studies. Many infants in both groups 
had evidence of peripheral airflow obstruction 
at tidal breathing and on forced expiration as 
measured by thoracoabdominal compression. In 
infants with gastroesophageal reflux (GER), 
only 9 of 54 (16.6%) responded to bronchodi- 
lator therapy compared to 20 of 30 (66.6%) in 
the group with negative pH probe studies (p < 
0.0005). In infants with positive pH studies, 
family history of asthma (n = 16) correlated 
well with positive response to bronchodilators 
(p < 0.0005), and all infants exposed to mater- 
nal smoking (n = 11) had no response to bron- 
chodilators. Forty-four percent of infants with a 
positive pH probe had no gastrointestinal symp- 
toms suggestive of GER. In infants with a neg- 
ative pH probe, family history of asthma (n = 
24) correlated well with positive response to 
bronchodilators (p < 0.0005), and exposure to 
maternal smoking (n = 8) correlated well with 
no response to bronchodilator therapy p< 
0.0005). We conclude that silent GER is com- 
mon in infants with persistent wheezing. Fur- 
thermore, infants with GER are less likely to 
respond to bronchodilator therapy, and expo- 
sure to maternal smoking and family history of 
asthma may be significant independent factors. 

Synchronized Gas and Partial Liquid Venti- 
lation in Lung-Injured Animals: Improved 
Gas Exchange with Decreased Effort — Ben- 
del-Stenzel EM, Bing DR, Meyers PA, Connett 
JE, Mammel MC. Pediatr Pulmonol 1999 Apr; 

We hypothesized that partial liquid ventilation 
(PLV) with perflubron in spontaneously breath- 
ing lung-injured animals would increase respi- 
ratory workload compared to animals treated 
with gas ventilation (GV), and that a fully syn- 
chronized mode, assist-control ventilation (AC), 
would reduce the piglets' effort when compared 
to intermittent mandatory ventilation (IMV) or 
synchronized IMV (SIMV) during both GV and 
PLV. Newborn piglets with saline lavage-in- 
duced lung injury were randomized to sequen- 
tial 30-min periods of IMV -^ SIMV -^ AC 
(n = 5), or AC -» SIMV -^ IMV (n = 5) 
during GV followed by PLV. Pulmonary me- 
chanics measurements and an esophageal pa- 
tient effort index (PEI, defined as the product of 
the area below baseline of the esophageal pres- 
sure-time curve and respiratory rate [RR]) were 
determined to estimate the patient's nonme- 
chanical work of breathing, using a computer- 
assisted lung mechanics analyzer. GV to PLV 
comparisons showed no change in PEI (IMV, 
57.8 vs. 49.7; SIMV, 52.3 vs. 46.8; AC, 15.7 
vs. 13.7 cm HjO x s/min); intermode compar- 
isons showed significantly decreased PEI in AC 

vs. IMV and SIMV during GV, and in AC vs. 
SIMV (AC vs. IMV, p = 0.06) during PLV. 
AC consistently resulted in the highest minute 
ventilation, lowest total respiratory rate, most 
physiologic pH, and least tidal volume variabil- 
ity. These observations suggest that synchroni- 
zation with AC during GV and PLV may have 
substantial physiologic benefits. 

Lung Function Measures and Their Rela- 
tionship to Respiratory Symptoms in 7- and 
8- Year-Old Children— Droste JH, Wieringa 
MH, Weyler JJ, Nelen VJ, Van Bever HP, Ver- 
meire PA. Pediatr Pulmonol 1999 Apr;27(4): 

Abnormal pulmonary function in childhood is a 
well-known risk factor for lung function im- 
pairment in adult life. It is therefore of clinical 
interest to recognize lower pulmonary function 
in childhood. We investigated the association 
between asthma-like respiratory symptoms and 
the lung function parameters FVC, FEV,, and 
FEF25_75 in a population-based sample of 402 
schoolchildren, aged 7 and 8 years, using linear 
regression analyses. Without accounting for 
other respiratory symptoms, wheeze, exercise- 
induced wheeze, chronic cough, and history of 
wheezy bronchitis or lower respiratory infec- 
tions in early childhood were significantly as- 
sociated with reduced lung function. After step- 
wise elimination of symptoms from the 
regression models, only exercise-induced 
wheeze (FEV,, -15%pred, FEF25_,5, 
-21%pred) and a history of chronic cough 
(FEV,, -5%pred; FEFj,_„, -ll%pred) re- 
mained significant predictors of decreased lung 
function. After adjustment for different vari- 
ability, no significant differences were seen be- 
tween the effects of symptoms on the flow mea- 
surements FEV, and FEF25_75. We conclude 
that children who report exercise-induced 
wheeze and/or chronic cough may have a con- 
siderable deficit in lung function at early school 

Evaluation of Home Audiotapes as an Ab- 
breviated Test for Obstructive Sleep Apnea 
Syndrome (OSAS) in Children — Lamm C, 
Mandeli J, Kattan M. Pediatr Pulmonol 1999 

Snoring occurs commonly in children and is 
sometimes associated with obstructive sleep ap- 
nea syndrome (OSAS). Based on clinical his- 
tory alone, it is difficult to distinguish primary 
snoring, characterized by noisy breathing dur- 
ing sleep without apnea or hypoventilation, from 
snoring indicative of OSAS. An overnight poly- 
somnogram (PSG) is required to establish a de- 
finitive diagnosis of OSAS. sleep eval- 
uations are costly and resources are limited, we 
evaluated whether a home audiotape recording 
could accurately identify children with OSAS. 
We studied 36 children referred by pediatri- 


Respiratory Care • July 1999 Vol 43 No 7 


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cians and otolaryngologists for possible OSAS. 
Parents completed a questionnaire about their 
child's sleep and breathing and made a 15-min 
audiotape of the child's breath sounds during 
sleep. Overnight PSGs were performed on all 
patients. There were 29 patients who completed 
the study: 1.^ patients in the Primary Snoring 
group (apnea/hypopnea index < 5) and 14 pa- 
tients in the OSAS group (apnea/hypopnea in- 
dex a 5). No significant statistical differences 
existed between the two groups for physical 
characteristics or questionnaire responses. 
Seven observers analyzed the audiotapes for the 
presence of a struggle sound and respiratory The median sensitivity of the audiotape 
as a predictor of OSAS was 71% (range 43- 
86%), and the median specificity was 80% 
(range 67-80%). The presence of a struggle 
sound on the audiotape was the parameter most 
predictive of OSAS. There was a good level of 
agreement among the seven audiotape observ- 
ers, as demonstrated by a mean and range kappa 
statistic of 0.70 (0.50-0.9.3) for the 21 pairs of 
observers. Using a clinical score to predict 
OSAS, the sensitivity was 46%. and the spec- 
ificity was 83%. We conclude that findings on 
a home audiotape can be suggestive of OSAS, 
but are not sufficiently specific to reliably dis- 
tinguish primary snoring from OSAS. 

Delivery Room Management of Extremely 
Low Birth Weight Infants: Spontaneous 
Breathing or Intubation? — Lindner W, Voss- 
beck S, Hummler H, Pohlandt F. Pediatrics 1 999 
May; 103(5 Pt l):96l-967. 

Objective. To study the effect of two different 
delivery room (DR) policies on the rate of en- 
dotracheal intubation and mechanical ventila- 
tion (EI/MV) and short term morbidity in ex- 
tremely low birth weight infants (ELBWI; 
<I000 g, a 24 weeks). Methods. Retrospec- 
tive cohort study of 123 inborn ELBWIs bom 
in 1994 and in 1996. DR policies have changed. 
Until 1994, ELBWIs were intubated immedi- 
ately after delivery when presenting the slight- 
est signs of respiratory distress or asphyxia af- 
ter initial resuscitation using a face mask and a 
handbag. During 1995, the guidelines for respi- 
ratory support were changed. In 1996, contin- 
uous (15 to 20 seconds), pressure controlled 
(20 to 25 cm HjO) inflation of the lungs using 
a nasal pharyngeal tube, followed by continu- 
ous positive airway pressure (CPAP; 4 to 6 cm 
HjO) was applied to all ELBWIs immediately 
after delivery to establish a functional residual 
capacity and perhaps to avoid EI/MV. In addi- 
tion to the changes in respiratory support, the 
prevention of conductive and evaporative heat 
loss was improved in 1996. For analysis of mor- 
bidity and mortality, infants were matched for 
gestational age and birth weight. Results. The 
rate of EI/MV in the DR decreased from 84% 
in 1994 to 40% in 1996. In 1996, 25% of the 
ELBWIs were never intubated (7% in 1994), 

but 35% of the ELBWIs needed secondary EI/ 
MV, primarily because of respiratory distress 
syndrome (RDS). Initial ventilator settings, ven- 
tilator days, mortality, and morbidity were not 
different between ELBWIs with EI/MV in 
the DR and infants with secondary EI/MV at- 
tributable to RDS in the intensive care unit. 
ELBWIs with no EI/MV that was caused by 
RDS had a lower morbidity (ie, bronchopulmo- 
nary dysplasia, intraventricular hemorrhage 
>grade 2 and/or periventricular leukomalacia), 
mortality, and fewer hospital days (mean: 79 vs 
105 days). The incidence of gastrointestinal ad- 
verse effects like feeding intolerance or necro- 
tizing enterocolitis was not increased in 1996. 
Paco, W''** significantly higher at admission to 
the neonatal unit in ELBWIs with CPAP in 
1996 (54 ± 15 mm Hg, 7.2 ± 2.0 kPa) com- 
pared with infants with EI/MV in 1994 (38 ± 
1 1 mm Hg, 5.1 ± 1. 5 kPa. A total of 26% of 
spontaneously breathing infants had hypercap- 
nia (Paco, — 60 mm Hg [8.0 kPa]), compared 
with 7% of infants with EI/MV in 1994. Within 
the first few hours of life, Paco, decreased to 46 
(32 to 57) mm Hg (6. 1 [4.3 to 7".6| kPa) in never 
intubated ELBWIs (n = 17), but increased to 
70 (57 to 81) mm Hg (9.3 [7.6 to 10.8] kPa) in 
ELBWIs (n = 14) with RDS and secondary 
EI/MV (age 5.5 [ 1 to 44[ hours). Conclusions. 
In our setting, the individualized intubation strat- 
egy in the DR restricted EI/MV to those ELB- 
WIs who ultimately needed it, without increas- 
ing morbidity or mortality in infants with 
secondary EI/MV attributable to RDS. We spec- 
ulate that an individualized intubation strategy 
of the ELBWI is superior to immediate intuba- 
tion of all ELBWIs with slight signs of respi- 
ratory distress after birth. 

Prognostic Models of Thirty-Day Mortality 
and Morbidity After Major Pulmonary Re- 
section — Harpole DH Jr, DeCamp MM Jr, Da- 
ley J, Hur K, Oprian CA. Henderson WG, Khuri 
SF. J Thorac Cardiovasc Surg 1999May;l 17(5): 

BACKGROUND:A part of the prospective, 
multi-institutional National Veterans Affairs 
Surgical Quality Improvement Program was de- 
veloped to predict 30-day mortality and mor- 
bidity for patients undergoing a major pulmo- 
nary resection. Methods: Perioperative data 
were acquired from 194,319 noncardiac surgi- 
cal operations at 1 23 Veterans Affairs Medical 
Centers between October I, 1991, and August 
31,1 995. Current Procedural Terminology code- 
based analysis was undertaken for major pul- 
monary resections (lobectomy and pneumonec- 
tomy). Preoperative, intraoperative, and 
outcome variables were collected. The 30-day 
mortality and morbidity models were developed 
by means of multivariable stepwise logistic re- 
gression with the preoperative and intraopera- 
tive variables used as independent predictors of 
outcome. Results: A total of 35 16 patients (mean 

age 64 ± 9 years) underwent either lobectomy 
(n = 2949) or pneumonectomy (n = 567). Thir- 
ty-day mortality was 4.0% for lobectomy (119/ 
2949) and 1 1 .5% for pneumonectomy (65/567). 
The preoperative predictors of 30-day mortality 
were albumin, do not resuscitate status, trans- 
fusion of more than 4 units, age. disseminated 
cancer, impaired sensorium. prothrombin time 
more than 12 seconds, type of operation, and 
dyspnea. When the intraoperative variables w,^e 
considered, intraoperative blood loss was added 
to the preoperative model. In the presence of 
these intraoperative variables in the model, do 
not resuscitate status and prothrombin time more 
than 12 seconds were only marginally signifi- 
cant. Thirty-day morbidity, defined as the pres- 
ence of 1 or more of the 2 1 predefined compli- 
cations, was 23.8% for lobectomy (703/2949) 
and 25.7% for pneumonectomy (146/567). In 
multivariable models, independent preoperative 
predictors (p <.05) of 30-day morbidity were 
age, weight loss greater than 1 0% in the 6 months 
before surgery, history of chronic obstructive 
pulmonary disease, transfusion of more than 4 
units, albumin, hemiplegia, smoking, and dys- 
pnea. When intraoperative variables were added 
to the preoperative model, the duration of op- 
eration time and intraoperative transfusions were 
included in the model and albumin became mar- 
ginally significant. Conclusions: This analy.sis 
identifies independent patient risk factors that 
are associated with 30-day mortality and mor- 
bidity for patients undergoing a major pulmo- 
nary resection. This .series provides an initial 
risk-adjustment model for major pulmonary re- 
sections. Future refinements will allow com- 
parative assessment of surgical outcomes and 
quality of care at many institutions. 

Systematic Review of Antistaphylococcal An- 
tibiotic Therapy in Cystic Fibrosis — McCaf- 
fery K, Olver RE, Franklin M, Mukhopadhyay 
S. Thorax 1999 May;54(5):380-383. 

BACKGROUND: The respiratory tract in pa- 
tients with cystic fibrosis is frequently colo- 
nised with Staphylococcus aureus. There is great 
diversity of clinical practice in this area of cy.s- 
tic fibrosis. A systematic review was conducted 
to study the evidence relating antistaphylococ- 
cal therapy to clinical outcoine in patients with 
cystic fibrosis. METHODS: A .search strategy 
already evaluated for the study of the epidemi- 
ology of cystic fibrosis clinical trials was used. 
This yielded 3188 references from which 13 
clinical trials of antistaphylococcal therapy were 
identified. RESULTS: Substantial heterogene- 
ity was observed between trials. In the 13 clin- 
ical trials a total of 19 antibiotics were used to 
assess a wide variety of outcome measures (1 1 
clinical, six laboratory). Both intermittent and 
continuous treatment strategies were used. Spu- 
tum clearance of 5 aureus was more frequently 
achieved than any other beneficial outcome. A 
beneficial effect on pulmonary function was 


Respiratory Care • July 1999 Vol 43 No 7 

rarely measured or observed. Although five ran- 
domised chnical trials were identified, the ex- 
tent of heterogeneity precluded the use of meta- 
analysis for further synthesis of information. 
CONCLUSIONS: Antistaphylococcal treat- 
ment achieves sputum clearance of 5 aureus in 
patients with cystic fibrosis. Prophylactic anti- 
staphylococcal treatment in young children with 
cystic fibrosis is likely to be of clinical benefit. 
It remains to be determined whether the use of 
"prophylactic" versus "intermittent" antistaphy- 
lococcal therapy in cystic fibrosis is associated 
with improved lung function and/or chest ra- 
diographic scores, an increase in bacterial re- 
sistance, or earlier acquisition of Pseudomona.s 
aeruginosa. A large randomised clinical trial 
lasting approximately two years is urgently re- 
quired to address this problem. 

Oral Airway Resistance During Wakefulness 
in Patients with Obstructive Sleep Apnoea — 

Amis TC, O'Neill N, Wheatley JR. Thorax 1999 

BACKGROUND: Patients with obstructive 
sleep apnoea (OSA) have a number of upper 
airway structural abnormalities which may in- 
fluence the resistance of the oral airway to air- 
flow. There have been no systematic studies of 
the flow dynamics of the oral cavity in such 
patients. METHODS: Inspiratory oral airway 
resistance to airflow (RO) was measured in 13 
awake patients with OSA in both the upright 
and supine positions (neck position constant). 
Each subject breathed via a mouthpiece while 
the nasal airway was occluded with a nasal mask. 
RESULTS: In the upright position the mean 
(SE) RO was 1.26 (0.19) cm H,0/L/s (at 0.4 
L/s) which increased to 2.01 (0.43) cm H^O/L/s 
when supine (p<0.0.5, paired f test). The mag- 
nitude of this change correlated negatively with 
the respiratory disturbance index (r = -0.60, 
p = 0.03). CONCLUSION: In awake patients 
with OSA RO is normal when upright but ab- 
normally raised when in the supine position. 

A Pliysiological Comparison of Flutter Valve 
Drainage Bags and Underwater Seal Systems 
for Postoperative Air Leaks — Waller DA, Ed- 
wards JG. Rajesh PB. Thorax 1999 May:54(5): 

BACKGROUND: A study was undertaken to 
compare the relative physiological effects of 
underwater seal (UWS) versus flutter valve (FV) 
pleural drainage systems in the treatment of post- 
operative air leaks. METHOD: Fourteen patients 
with air leaks of 1-1 1 days duration, following 
lobectomy (n = 5), buUectomy (n = 4), decor- 
tication (n = 4), and pleural biopsy (n = I) 
were analysed. Intrapleural pressure (IPP) mea- 
surements were made using an in-line external 
strain gauge connected directly to the intercos- 
tal tube. Patients were connected simultaneously 
to both UWS and FV drainage systems and 

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pressures were measured sequentially, isolating 
each system in turn. Maximum (IPPmax) and 
minimum (IPPmin) intrapleural pressures were 
calculated from graphic traces. The degree of 
lung expansion was recorded by chest radiog- 
raphy. RESULTS: At resting tidal volume 
IPPmax was significantly higher with the UWS 
system (mean difference 0.8 mm Hg, 95% CI 
to 1 .6, p = 0.046) and IPPmin was significantly 
lower with the FV system ( 1 .8 mm Hg, 9.S% CI 
0.3 to 3.3, p = 0.023). The lung was fully ex- 
panded in 50% of patients at the time of study. 
The mean difference in IPPmin between sys- 
tems was significantly increased when the lung 
was fully expanded (mean 2.8 mm Hg, 95% CI 
0.1 to 5.5, p = 0.042). The mean difference in 
IPPmax was not affected by the degree of lung 
expansion (0.79, 95% CI -0.83 to 2.4, p = 
0.31). CONCLUSION: The results of this study 
suggest that, when postoperative air leak exists 
without a persistent pleural space, the flutter 
valve may provide a physiologically more ef- 
fective alternative to the underwater seal drain- 
age system. 

Reducing the Rate of Nosocomially Trans- 
mitted Respiratory Syncytial Virus — Karan- 
fil LV, Conlon M, Lykens K. Masters CF. For- 
man M, Griffith ME, et al. Am J Infect Control 
1999 Apr;27(2):91-96. 

BACKGROUND: A large number ( 1 7) of nos- 
ocomial respiratory syncytial virus cases led to 
the development of control measures to prevent 
transmission of respiratory syncytial virus 
(RSV) within the Johns Hopkins Hospital's 
Children's Center. METHODS: The control 
plan is based on a 2-stage process. In stage 1, 
the staff are notified that RSV is in the com- 
munity, and information is distributed through 
a communication tree. Stage 2 requires that na- 
sopharyngeal aspirates be obtained from all chil- 
dren < 3 years of age who have respiratory 
symptoms. The aspirates are tested directly for 
RSV antigen and cultured for RSV. The chil- 
dren are placed on pediatric droplet precautions 
pending those results. RESULTS: The propor- 
tion of nosocomial RSV cases dropped from 
16.5% before the use of RSV control measures 
to 7.2% after the initiation of the control pro- 
gram. A case of RSV identified in the hospital 
was 2.6 times more likely to be nosocomially 
acquired before the intervention compared with 
after the intervention. Approximately 14 cases 
of RSV are prevented each year, which results 
in a savings of 56 hospital-days and more than 
$84,000 in direct hospital-related charges alone. 
CONCLUSIONS: The nosocomial spread of 
RSV can be reduced by a specific and feasible 
control plan that includes early identification 
and rapid isolation of potential RSV cases. 

Respiratory Care • July 1 999 Vol 43 No 7 



Bacterial Contamination of the Hands of Hos- 
pital Staff During Routine Patient Care — 

Pittet D. Dharan S, Touveneau S, Sauvan V, 
Pemeger TV, Arch Intern Med 1999 Apr 26; 

BACKGROUND: Cross-transmission of micro- 
organisms by the hands of health care workers 
is considered the main route of spread of nos- 
ocomial infections. OBJECTIVE: To study the 
process of bacterial contamination of health care 
workers' hands during routine patient care in a 
large teaching hospital. METHODS: Structured 
observations of 417 episodes of care were con- 
ducted by trained external observers (S.T. and 
V.S.). Each observation period started after a 
hand-cleansing procedure and ended when the 
health care worker proceeded to clean his or her 
hands or at the end of a coherent episode of 
care. At the end of each period of observation, 
an imprint of the 5 fingertips of the dominant 
hand was taken and bacterial colony counts were 
quantified. Regression methods were used to 
model the intensity of bacterial contamination 
as a function of method of hand cleansing, use 
of gloves during patient care, duration and type 
of care, and hospital ward. RESULTS: Bacte- 
rial contamination increased linearly with time 
on ungloved hands during patient care (aver- 
age, 1 6 colony-forming units [CPUs] per minute; 
9.S% confidence interval, 11-21 CPUs per 
minute). Patient care activities independently 
(p < 0.05 for all) associated with higher con- 
tamination levels were direct patient contact, 
respiratory care, handling of body fluid secre- 
tions, and rupture in the sequence of patient 
care. Contamination levels varied with hospital 
location; the medical rehabilitation ward had 
higher levels (49 CPUs; p = 0.03) than did 
other wards. Pinally, simple hand washing be- 
fore patient care, without hand antisepsis, was 
also associated with higher colony counts (52 
CPUs; p = 0.03). CONCLUSIONS: The dura- 
tion and type of patient care affect hand con- 
tamination. Furthermore, because hand antisep- 
sis was superior to hand washing, intervention 
trials should explore the role of systematic hand 
antisepsis as a cornerstone of infection control 
to reduce cross-transmission in hospitals. 

In-Hospital Cardiopulmonary Resuscitation: 
Prearrest Morbidity and Outcome — de Vos 

R, Koster RW, De Haan RJ, Oosting H, van der 
Wouw PA, Lampe-Schoenmaeckers AJ. Arch 
Intern Med 1999 Apr 26;l59(8):845-850. 

BACKGROUND: Considerations about the ap- 
plication of cardiopulmonary resuscitation 
(CPR) should include the expected probability 
of survival. The survival probability after CPR 
may be more accurately estimated by the oc- 
currence in time of the prearrest morbidity of 
patients. OBJECTIVE: To identify risk factors 
for poor survival after CPR in relation to the 
dynamics of prearrest morbidity. METHODS: 

Medical records of CPR patients were reviewed. 
Prearrest morbidity was established by catego- 
rizing the medical diagnoses according to 3 func- 
tional time frames: before hospital admission, 
on hospital admission, and during hospital ad- 
mission. Indicators of poor survival after CPR 
were identified through a logistic regression 
model. RESULTS: Included in the study were 
553 CPR patients with a median age of 68 years 
(age range, 18-98 years); 21.7% survived to 
hospital discharge. Independent indicators of 
poor outcome were an age of 70 years or older 
(odds ratio [OR] =0.6, 95% confidence interval 
[CI] = 0.4-0.9), stroke (OR=0.3, 95% CI=0. 1- 
0.7) or renal failure (OR=0.3, 95% CI=0.1- 
0.8) before hospital admission, and congestive 
heart failure during hospital admission 
(OR=0.4, 95% CI=0.2-0.9). Indicators of good 
survival were angina pectoris before hospital 
admission (OR = 2. 1 , 95% CI= 1 .3-.3.3) or ven- 
tricular dysrhythmia as the diagnosis on hospi- 
tal admission (OR=11.0, 95% CI=4.1-33.7). 
Ba,sed on a logistic regression model, 17.4% of 
our CPR patients (n= 96) were identified as 
having a high risk for a poor outcome (< 10% 
survival). CONCLUSIONS: Time of prearrest 
morbidity has a prognostic value for survival 
after CPR. Patients at risk for poor survival can 
be identified on or during hospital admission, 
but the reliability and validity of the model needs 
further research. Although decisions will not be 
made by the model, its information can be use- 
ful for physicians in discussions about patient 
prognoses and to make decisions about CPR 
with more confidence. 

Spontaneous Breathing During Ventilatory 
Support Improves Ventilation-Perfusion Dis- 
tributions in Patients with Acute Respira- 
tory Distress Syndrome — Putensen C, Mutz 
NJ, Putensen-Himmer G, Zinserling J. Am J 
Respir Crit Care Med 1999 Apr;159(4 Pt 1): 

Ventilation-perfusion (V^/Q) distributions were 
evaluated in 24 patients with acute respiratory 
distress syndrome (ARDS), during airway pres- 
sure release ventilation (APRV) with and with- 
out spontaneous breathing, or during pressure 
support ventilation (PSV). Whereas PSV pro- 
vides mechanical assistance of each inspiration, 
APRV allows unrestricted spontaneous breath- 
ing throughout the mechanical ventilation. Pa- 
tients were randomly assigned to receive APRV 
and PSV with equal airway pressure limits (Paw) 
(n = 12) or minute ventilation (V^-) (n = 12). 
In both groups spontaneous breathing during 
APRV was associated with increases (p < 0.05) 
in right ventricular end-diastolic volume, stroke 
volume, cardiac index (CI), P„o,, oxygen deliv- 
ery, and mixed venous oxygen tension (Pvo,) 
and with reductions (p < 0.05) in pulmonary 
vascular resistance and oxygen extraction. PSV 
did not consistently improve CI and ?„„, when 
compared with APRV without spontaneous 

breathing. Improved V^/Q matching during 
spontaneous breathing with APRV was evi- 
denced by decreases in intrapulmonary shunt 
(equal Paw: 33 ± 4 to 24 ± 4%; equal V^: 
32 ± 4 to 25 ± 2%) (p < 0.05), dead space 
(equal Paw: 44 ± 9 to 38 ± 6%; equal W^: 
44 ± 9 to 38 ± 6%) (p < 0.05), and the dis- 
persions of ventilation (equal Paw: 0.96 ± 0.23 
to 0.78 ± 0.22; equal V^: 0.92 ± 0.23 to 0.79 ± 
0.22) (p < 0.05), and pulmonary blood flow 
distribution (equal Paw: 0.89 ± 0.12 to 0.72 ± 
0.10; equal V^: 0.94 ± 0.19 to 0.78 ± 0.22) 
(p < 0.05). PSV did not improve V^/Q distri- 
butions when compared with APRV without 
spontaneous breathing. These findings indicate 
that uncoupling of spontaneous and mechanical 
ventilation during APRV improves V^^/Q match- 
ing in ARDS presumably by recruiting nonven- 
tilated lung units. Apparently, mechanical as- 
sistance of each inspiration during PSV is not 
sufficient to counteract the V^/Q maldistribu- 
tion caused by alveolar collapse in patients with 

The Attributable Morbidity and Mortality 
of Ventilator-Associated Pneumonia in the 
Critically III Patient— Heyland DK, Cook DJ, 
Griffith L, Keenan SP, Brun-Buisson C. Am J 
Respir Crit Care Med 1999 Apr; 159(4 Pt 1): 

To evaluate the attributable morbidity and mor- 
tality of ventilator-associated pneumonia (VAP) 
in intensive care unit (ICU) patients, we con- 
ducted a prospective, matched cohort study. Pa- 
tients expected to be ventilated for > 48 h were 
prospectively followed for the development of 
VAP. To determine the excess ICU stay and 
mortality attributable to VAP, we matched pa- 
tients with VAP to patients who did not de- 
velop clinically suspected pneumonia. We also 
conducted sensitivity analyses to examine the 
effect of different populations, onset of pneu- 
monia, diagno.stic criteria, causative organisms, 
and adequacy of empiric treatment on the out- 
come of VAP. One hundred and .seventy-seven 
patients developed VAP. As compared with 
matched patients who did not develop VAP, 
patients with VAP stayed in the ICU for 4.3 d 
(95% confidence interval [CI]: 1.5 to 7. d) 
longer and had a trend toward an increase in 
risk of death (absolute risk increase: 5.8%; 95% 
CI: -2.4 to 14.0 d; relative risk (RR) increase: 
32.3%; 95% CI: -20.6 to 85.1%). The attrib- 
utable ICU length of stay was longer for med- 
ical than for surgical patients (6. 5 versus 0.7 d, 
p < 0.004), and for patients infected with "high 
risk" organisms as coinpared with "low risk" 
organisms (9. 1 d versus 2.9 d). The attributable 
mortality was higher for medical patients than 
for surgical patients (RR increase of 65% ver- 
sus -27.3%, p = 0. 04). Results were similar 
for three different VAP diagnostic criteria. We 
conclude that VAP prolongs ICU length of stay 
and may increase the risk of death in critically 


RESPIRATORY Care • JuLY 1999 VoL 43 No 7 

ill patients. The attributable risk of VAP ap- 
pears to vary with patient population and in- 
fecting organism. 

Isocapnic Hyperpnea Accelerates Carbon 
Monoxide Elimination — Fisher JA. Rucker J, 
Somnier LZ, Vesely A, Lavine E, Greenwald 
Y, et al. Am J Respir Crit Care Med 1999 Apr; 
159(4 Pt 1):1289-1292. 

A major impediment to the use of hyperpnea in 
the treatment of CO poisoning is the develop- 
ment of hypocapnia or discomfort of COj in- 
halation. We examined the effect of nonrebreath- 
ing isocapnic hyperpnea on the rate of decrease 
of carboxyhemoglobin levels (COHb) in five 
pentobarbital-anesthetized ventilated dogs first 
exposed to CO and then ventilated with room 
air at normocapnia (control). They were then 
ventilated with 100% O, at control ventilation, 
and at six times control ventilation without hy- 
pocapnia ("isocapnic hyperpnea") for at least 
42 min at each ventilator setting. We measured 
blood gases and COHb. At control ventilation, 
the half-time for elimination of COHb (tl/2) 
was 212 ± 17 min (mean ± SD) on room air 
and 42 ± 3 min on 100% O,. The tl/2 de- 
creased to 18 ± 2 min (p < 0.0005) during 
isocapnic hyperpnea. In two similarly prepared 
dogs treated with hyperbaric Oj, the tl/2 were 
20 and 28 min. We conclude that isocapnic 
hyperpnea more than doubles the rate of COHb 
elimination induced by normal ventilation with 
100% O,. Isocapnic hyperpnea could improve 
the efficacy of the standard treatment of CO 
poisoning, 1 00% Oj at atmospheric or increased 

Can Intensive Support Improve Continuous 
Positive Airway Pressure Use in Patients with 
the Sleep Apnea/Hypopnea Syndrome? — 

Hoy CJ, Vennelle M, Kingshott RN, Engleman 
HM. Douglas NJ. Am J Respir Crit Care Med 
1999 Apr;159(4 Pt 1):1096-1 100. 

Continuous positive airway pressure (CPAP) 
therapy is widely prescribed for patients with 
the sleep apnea/hypopnea syndrome (SAHS), 
but the use of CPAP for such patients is disap- 
pointingly low. We postulated that providing 
intensive educational programs and nursing sup- 
port to SAHS patients might improve CPAP 
use and outcomes. We also examined the hy- 
pothesis that CPAP use would be greater among 
patients who had initiated their own referral 
than among those asked to seek help by a part- 
ner. We randomized 80 consecutive, new pa- 
tients with SAHS to receive either usual sup- 
port or additional nursing input including CPAP 
education at home and involving their partners, 
a 3-night trial of CPAP in our institution's sleep 
center, and additional home visits once they 
had begun CPAP. The primary outcome vari- 
able was objective CPAP use; symptoms, mood, 
and cognitive function were also assessed after 


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6 mo. CPAP use over 6 mo was greater (p = 
0.003) among patients receiving intensive than 
among those receiving standard support (5.4 ± 
0.3 versus 3.9 ± 0. 4 h/night [mean ± SEM]), 
with greater improvements (p < 0.05) in SAHS 
symptoms, mood, and reaction time in the in- 
tensively supported group. CPAP use was 
greater (p = 0.002) among patients who initi- 
ated their own referrals. CPAP use and out- 
comes of therapy can be improved by provision 
of a nurse-led intensive CPAP education and sup- 
port program. CPAP use is lower among patients 
whose partners ask them to seek treatment. 

Long-Term Use of CPAP Therapy for Sleep 
Apnea/Hypopnea Syndrome — McArdle N, 
Devereux G, Heidarnejad H, Engleman HM, 
Mackay TW, Douglas NJ. Am J Respir Crit 
Care Med 1999 Apr; 159(4 Pt l):l 108-1 1 14. 

Patients with the sleep apnea/hypopnea syn- 
drome (SAHS) treated by nasal continuous pos- 
itive airway pressure (CPAP) need to use CPAP 
long-term to prevent recurrence of symptoms. 
It is thus important to clarify the level of long- 
term CPAP use and the factors influencing long- 
term use. We examined determinants of objec- 
tive CPAP use in I, 211 consecutive patients 
with SAHS who were prescribed a CPAP trial 
between 1986 and 1997. Prospective CPAP use 
data were available in 1, 155 (95.4%), with a 

median follow-up of 22 mo (interquartile range 
[IQRl, 12 to 36 mo). Fifty-two (4.5%) patients 
refused CPAP treatment (these were more often 
female and current smokers); 1 . 1 03 patients took 
CPAP home, and during follow-up 20% stopped 
treatment, primarily because of a lack of ben- 
efit. Methods of survival analysis showed that 
68% of patients continued treatment at 5 yr. 
Independent predictors of long-term CPAP use 
were snoring history, apnea/hypopnea index 
(AHI), and Epworth score; 86% of patients with 
Epworth > 10 and an AHI a 30 were still 
using CPAP at 3 yr. Average nightly CPAP use 
within the first 3 mo was .strongly predictive of 
long-term use. We conclude that long-term 
CPAP use is related to disease severity and 
subjective sleepiness and can be predicted 
within 3 mo. 

Patient Perception of Sleep Quality and Eti- 
ology of Sleep Disruption in the Intensive 
Care Unit — Freedman NS, Kotzer N, Schwab 
RJ. Am J Respir Crit Care Med 1999 Apr;I59(4 

Pt 1):1 155-1 162. 

The etiology of sleep disruption in patients in 
intensive care units (ICUs) is poorly understood, 
but is thought to be related to environmental 
stimuli, especially noise. We sampled 203 pa- 
tients (121 males and 82 females) from differ- 
ent ICUs (cardiac [CCU], cardiac stepdown 

Respiratory Care • July 1999 Vol 43 No 7 



[CICU], medical [MICU], and surgical [SICU]) 
by questionnaire on the day of their discharge 
from the unit, to determine the perceived effect 
of environmental stimuli on sleep disturbances 
in the ICU. Perceived ICU sleep quality was 
significantly poorer than baseline sleep at home 
(p = 0.0001 ). Perceived sleep quality and day- 
time sleepiness did not change over the course 
of the patients' stays in the ICU, nor were there 
any significant differences (p > 0.05) in these 
parameters among respective units. Disruption 
from human interventions and diagnostic test- 
ing were perceived to be as disruptive to sleep 
as was environmental noise. In general, patients 
in the MICU appeared to be more susceptible to 
sleep disruptions from environmental factors 
than patients in the other ICUs. Our data show 
that; ( I ) poor sleep quality and daytime sleep- 
iness are problems common to all types of ICUs, 
and affect a broad spectrum of patients; and (2) 
the environmental etiologies of sleep disruption 
in the ICU are multifactorial. 

The Effect of Mode, Inspiratory Time, and 
Positive End-Expiratory Pressure on Partial 
Liquid Ventilation — Fujino Y, Kirmse M, Hess 
D. Kacmarek RM. Am J Respir Crit Care Med 
1999 Apr;159(4 Pt 1);1087-1095. 

Partial liquid ventilation (PLV) has been shown 
to be an effective means of improving oxygen- 
ation in the injured lung. However, little is 
known about how approach to ventilation dur- 
ing PLV affects gas exchange and pulmonary 
mechanics. We hypothesized that gas exchange 
and pulmonary mechanics would be best with 
positive end-expiratory pressure (PEEP) set 
above the lower inflection point (LIP) of the 
pressure-volume (P-V) curve regardless of mode 
of ventilation or inspiratory to expiratory time 
(I:E) ratio and that the efficiency of ventilation 
would be greatest with volume-controlled ven- 
tilation (VCV) compared with pressure-con- 
trolled ventilation (PCV) and with long inspira- 
tory time as compared with short inspiratory 
time. Lung injury was induced in 14 sheep by 
lavage, 10 of which were studied. Sheep were 
then assigned to high-PEEP (Group H, n = 5) 
and low-PEEP (Group L, n = 5) groups. In 
Group H applied PEEP was set at the LIP and 
in Group L applied PEEP was set at 5 cm HiO 
after the lung was filled with perflubron (PFB). 
We randomly compared VCV and PCV with 
I;E ratios of 1 :2, 1:1, and 2: 1 . Peak inspiratory 
pressure and V^ were adjusted to maintain a 
constant end-inspiratory plateau pressure (Ppi,,,) 
of about 25 cm H^O in both groups and a con- 
stant total PEEP of about 5 cm H,0 in Group L 
and about 12 cm HjO in Group H. There were 
no differences in oxygenation among modes in 
Group H. In Group L VCV 2: 1 and all of the 
PCV modes in Group L had a lower P.,,,, than 
VCV I;l (p < 0.05). P,„,, and V, At were 
significantly different (p < 0.05) among modes. 
ViAt was highest during PCV I ;2 with PEEP 

of 5 cm HjO (p < 0.05). Quasi-static compli- 
ance in Group H was higher than in Group L 
(p < 0.05). We conclude that during low PEEP 
gas exchange deteriorated in VCV with long 
inspiratory time and in PCV. Oxygenation was 
enhanced during VCV 1 ; I when compared with 
VCV at longer I:E ratios or PCV at any I;E 
ratio. With PEEP set at the LIP, adequate gas 
exchange and improved lung mechanics could 
be obtained in all modes assessed. 

Pressure- Volume Curves and Compliance in 
Acute Lung Injury: Evidence of Recruitment 
Above the Lower Inflection Point — Jonson B, 
Richard JC, Straus C, Mancebo J, Lemaire F. 
Brochard L. Am J Respir Crit Care Med 1999 
Apr; 159(4 Pt I ):1 172-1 178. 

Measuring elastic pressure-volume (Pel-V) 
curves of the respiratory system and the volume 
recruited by a positive end-expiratory pressure 
(PEEP) allows one to study the pressure range 
over which recruitment occurs in acute lung 
injury (ALI), and to explain how recruitment 
affects the compliance. Pel-V curves were mea- 
sured with the low flow inflation technique in 
1 1 patients mechanically ventilated for ALI. 
Curve I was recorded during inflation from the 
volume attained after a prolonged expiration (6 
s) at PEEP (9.0 ± 2.2 cm H,0), and Curve II 
after expiration to the elastic equilibrium vol- 
ume at zero end-expiratory pressure (ZEEP). 
By using the end-expiratory volume of the 
breaths, the curves were aligned on a common 
volume axis to determine the effect of a single 
complete expiration. In each patient. Curve II 
(from ZEEP) was shifted toward lower volumes 
than Curve I. The volume shift, probably due to 
derecruitment, was 205 ± 100 mL at 15 cm 
H,0 (p < 0.0 1 ) and 78 ± 93 mL at 30 cm H,0 
(p < 0.01); thus, during inflation from ZEEP, 
the volume deficit was successively regained 
over a pressure range up to at least 30 cm HjO. 
At any pressure, compliance was higher on the 
curve from ZEEP than from PEEP, by 10.0 ± 
8.7 mL/cm H^O at 15 cm HjO (p < 0.01), and 
by 5.4 ± 5.5 at 30 cm H,0 (p < 0.01). It is 
concluded that in ALI, a single expiration to 
ZEEP leads to lung collapse. High compliance 
during insufflation from ZEEP indicates that 
lung recruitment happens far above the lower 
inflection point of the Pel-V curve. 

The Presence and Sequence of Endotracheal 
Tube Colonization in Patients Undergoing 
Mechanical Ventilation — Feldman C, Kassel 
M, Cantrell J, Kaka S. Morar R, Goolam Ma- 
homed A, Philips JI. Eur Respir J 1999 Mar; 

Endotracheal tube colonization in patients un- 
dergoing mechanical ventilation was investi- 
gated. In the first part of this prospective study, 
the airway access tube was examined for the 
presence of secretions, airway obstruction and 

bacterial colonization, in cases undergoing ex- 
tubation or tube change. In the second part of 
the study, the sequence of oropharyngeal, gas- 
tric, respiratory tract and endotracheal tube col- 
onization was investigated by sequential swab- 
bing at each site twice daily for 5 days in 
consecutive noninfected patients. In the first 
part, it was noted that all airway access lubes of 
cases undergoing extubation had secretions lin- 
ing the interior of the distal third of the tube 
which were shown on scanning electron mi- 
croscopy to be a biofilm. Gram-negative micro- 
organisms were isolated from these secretions 
in all but three cases. In the second part, it was 
noted that the sequence of colonization in pa- 
tients undergoing mechanical ventilation was 
the oropharynx (36 h), the stomach (3660 h), 
the lower respiratory tract (60-84 h), and there- 
after the endotracheal tube (60-96 h). Nosoco- 
mial pneumonia occurred in 1 3 patients and in 
eight cases identical organisms were noted in 
lower respiratory tract secretions and in secre- 
tions lining the interior of the endotracheal tube. 
The endotracheal tube of patients undergoing 
mechanical ventilation becomes colonized rap- 
idly with micro-organisms commonly associ- 
ated with nosocomial pneumonia, and which 
may represent a persistent source of organisms 
causing such infections. 

Aerosol Recovery from Large- Volume Res- 
ervoir Delivery Systems Is Highly Dependent 
on the Static Properties of the Reservoir — 

van der Veen MJ, van der Zee JS. Eur Respir J 
1999 Mar;13(3):668-672. 

In this study, the role of electrostatic fields on 
aerosol recovery from a system with a large 
collapsible reservoir (30 L) was investigated. In 
addition, the efficacy of the reservoir method 
for bronchial challenge procedures was as.sessed 
in vivo. Aerosol recovery was determined by 
measuring the fraction of aerosol (0.05% 
99mTc-tagged human albumin solution) re- 
trieved from the reservoir. Before aerosol re- 
covery experiments, electrostatic fields in the 
reservoir were measured. Aerosol recovery var- 
ied significantly with wall thickness of the res- 
ervoir and presence of an antistatic coating 
(range 6.0-70.3%). A inverse relation- 
ship was found between the mean electrostatic 
field in the reservoir and aerosol recovery. The 
nebulized provocative concentration of hista- 
mine causing a 20% fall in forced expiratory 
volume in one second in asthmatics was found 
to be approximately half that of a standard 
method when compared with the reservoir sys- 
tem (mean ratio 2.24 (95% confidence interval, 
1.60-3.12)). Recovery from an aerosol deliv- 
ery sy.stem with a relatively large collapsible 
aerosol reservoir was highly dependent on the 
electrostatic field in the reservoir. In these sys- 
tems the use of electrostatic field dissipative 
material for the reservoir is therefore recom- 


Respiratory Care • July 1999 Vol 43 No 7 


Washing Plastic Spacers in Houseliold De- 
tergent Reduces Electrostatic Charge and 
Greatly Improves Delivery — Pierart F, 
Wildhaber JH. Vrancken I, Devadason SG, Le 
Souef PN. Eur Respir J 1999 Mar;13(3):673- 

Ionic detergents reduce electrostatic charge on 
plastic spacers, thereby improving in vitro drug 
delivery. The aim of this study was to gain 
practical information on the use of detergents 
and to evaluate the relevance of this informa- 
tion on in vivo drug deposition. Measurement 
of electrostatic charge and salbutamol particle 
size distribution was carried out on detergent- 
coated and noncoated plastic spacers. The effi- 
ciency of four household detergents was com- 
pared, and the influence of dilution and the 
duration of the antistatic effect were studied. In 
addition, the level of radiolabelled salbutamol 
deposition in the lungs of eight healthy adults 
was compared after inhalation through a new 
versus a detergent-coated spacer. In vitro, all 
tested detergents reduced the electrostatic charge 
on the spacer surface. This resulted in a mean 
increase of 37.4% (range 33.5-41.2) in small 
particle (< 6.8 microm) salbutamol output com- 
pared with water-rinsed/drip-dried spacers. Di- 
lution had no influence on the results and the 
effect lasted for at least four weeks. In vivo, the 
mean lung deposition of radiolabeled salbuta- 
mol in healthy subjects was 45.6% (range 43.4- 
49.5) through a detergent-coated spacer com- 
pared to 1 1. 5% (range 7.6-1 7. 9) through a static 
spacer (p < 0.001). In conclusion, hou.sehold 
detergents offer a simple and practical solution 
to the problem of static on plastic spacers and 
significantly improve both in vitro and in vivo 
delivery of salbutamol. 

Physiological Basis of Improvement After 
Lung Volume Reduction Surgery for Severe 
Emphysema: Where Are We? — Marchand E, 
Gayan-Ramirez G, De Leyn P, Decramer M. 
Eur Respir J 1999 Mar;13(3):686-696. 

Lung volume reduction surgery has become an 
accepted therapeutic option to relieve the symp- 
toms of selected patients with severe emphy- 
sema. In a majority of these patients, it causes 
objective as well as subjective functional im- 
provement. A proper understanding of the phys- 
iological determinants underlying these benefi- 
cial effects appears very important in order to 
better select patients for the procedure that is 
f. currently largely carried out on an empirical 
; basis. Lung volume reduction surgery has two 
' . distinct effects. Firstly, it causes an increa.sed 
i elastic recoil, which at least partially explains 
the enhanced maximal expiratory flow. Sec- 
ondly, it is associated with a reduction of hy- 
perinflation which allows for an increase in 
global inspiratory muscle strength and in dia- 
phragmatic contribution to tidal volume as well 
as a decrease in the inspiratory elastic load im- 

posed by the chest wall. Taken together, these 
effects result in a reduced work of breathing 
and in an enhanced maximal ventilation which 
both contribute to the increa.sed exercise capac- 
ity and reduced dyspnoea after surgery. The 
improved lung recoil and the reduced hyperin- 
flation after volume reduction surgery were the 
primary postulates upon which the usual selec- 
tion criteria for the procedure were based. It is 
now likely that these are correct. Nevertheless, 
some patients do not benefit from lung volume 
reduction surgery and the current literature does 
not allow for a refinement of the selection pro- 
cess from a physiological point of view. The 
exact mechanisms underlying the improvement 
in lung recoil, lung mechanics, and respiratory 
muscle function remain incompletely under- 
stood. Moreover, the effects of lung volume 
reduction surgery on gas exchange and pulmo- 
nary haemodynamics still need to be more fully 
investigated. An analysis of the characteristics 
of patients who do not benefit from the proce- 
dure and the development of an animal model 
for lung volume reduction surgery would prob- 
ably help address these important issues. 

Effects of Randomized Assignment to a 
Smoking Cessation Intervention and 
Changes in Smoking Habits on Respiratory 
Symptoms in Smokers with Early Chronic 
Obstructive Pulmonary Disease: The Lung 
Health Study— Kanner RE, Connett JE, Wil- 
liams DE, Buist AS. Am J Med 1999 Apr; 

PURPOSE: To evaluate the effects of randomly 
assigning smokers who have early chronic ob- 
structive pulmonary disease (COPD) to a smok- 
ing-cessation intervention on the symptoms of 
chronic cough, chronic phlegm production, 
wheezing and shortness of breath, and to deter- 
mine the effects of quitting smoking on these 
total of 5,887 male and female smokers 35 to 
60 years of age with early COPD [defined as a 
forced expiratory volume in the first second 
(FEV,) of 55% to 90% of predicted and FEV,/ 
forced vital capacity (FVC) < 0.70] were en- 
rolled in a 5-year clinical trial. Two-thirds of 
participants were randomly assigned to smok- 
ing-intervention groups and one-third to a usu- 
al-care group. The intervention groups attended 
1 2 intensive smoking-cessation .sessions that in- 
cluded behavior modification techniques and the 
use of nicotine chewing gum. One intervention 
group was treated with ipratropium bromide by 
inhaler; the other intervention group received 
placebo inhalers. The usual-care group was ad- 
vi.sed to stop smoking. All participants were 
followed annually. Smoking status was bio- 
chemically validated by salivary cotinine mea- 
surements or exhaled carbon monoxide values. 
RESULTS: Validated 5-year sustained smok- 
ing cessation occurred in 22% of participants in 
the intervention compared with only 5% of par- 

ticipants in the usual-care group. At the end of 
the study, the prevalence of each of the four 
symptoms in the two intervention groups was 
significantly less than in the usual-care group 
(p < 0.0001). For example, among participants 
who did not report cough at baseline, 15% of 
those in the intervention groups had cough at 
least 3 months during the year, compared with 
23% of those in usual care. Sustained quitters 
had the lowest prevalence of all four symp- 
toms, whereas continuous smokers had the great- 
est prevalence of these symptoms. Changes in 
symptoms occurred primarily in the first year 
after smoking cessation. Respiratory symptoms 
were associated with greater declines in FEV, 
during the study (p < 0.001). Ipratropium bro- 
mide had no long-term effects on respiratory 
symptoms. CONCLUSIONS: In this prospec- 
tive randomized trial using an intention-to-treat 
analysis, smokers with early COPD who were 
assigned to a smoking-cessation intervention 
had fewer respiratory symptoms after 5 years of 

Scintigraphy for Evaluating Early Aspira- 
tion After Oral Feeding in Patients Receiv- 
ing Prolonged Ventilation Via Tracheosto- 
my— Schonhofer B, Barchfeld T, Haidl P, 
Kohler D. Intensive Care Med 1999 Mar;25(3): 

OBJECTIVE: In tracheotomised patients the in- 
cidence of aspiration is difficult to determine 
because investigators often apply different cri- 
teria. In this study a scintigraphic method was 
used to visualise feeding aspiration directly and 
the results were compared with clinical evidence 
of a.spiration. DESIGN: Prospective study in 
difficult-to-wean patients with tracheostomy. 
METHODS: The study population consisted of 
62 con.secutive patients ( 1 6 females, age: 64. 1 ± 
11.1 years). All patients were tracheotomised 
and had previously been long-term ventilated in 
other ICUs due to weaning failure. The scinti- 
graphic test was performed during spontaneous 
breathing. The standard nutrition consisted of a 
liquid, semi-liquid and solid meal which was 
labelled with l(X) MBq 99mTc-human .serum 
Scintigraphic aspiration (SA) was defined as 
positive if radioactivity was detected in the bron- 
chial .system using a scintillation camera. Fur- 
thermore, aspiration was proven clinically (CA). 
CA and SA yielded identical results in 54 of the 
62 patients [ 10 positive (16%) and in 44 nega- 
tive (71%)]. CA, but not SA, was seen in 4/62 
(6.5%) and SA, but not CA, was found in 4/62 
(6.5%) patients. CONCLUSIONS: Our data re- 
emphasise that aspiration in tracheotomised pa- 
tients is common (in our study approximately 
30%). The scintigraphic method failed to iden- 
tify all tracheotomised patients with clinically 
significant aspiration; however, it did suggest 
that some patients had subclinical aspiration. 

Respiratory Care • July 1999 Vol 43 No 7 


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Dynamic Measurement of Intrinsic PEEP 
Does Not Represent tlie Lowest Intrinsic 

PEEP — Fujino Y, Nishimura M, Uchiyama A, 
Taenaka N, Yoshiya I. Intensive Care Med 1999 


OBJECTIVE: Dynamic intrinsic PEEP (PEEPi- 
dyn) is thie airway pressure required to over- 
come expiratory tlow and is considered to rep- 
resent the lowest regional PEEPi. However, 
there are few data to validate this assumption. 
We investigated if PEEPi-dyn represents the 
lowest PEEPi. SETTING: The animal labora- 
tory at the Osaka University Medical School. 
pared static PEEPi (PEEPi-stat) and PEEPi-dyn 
in healthy animals. Five adult white rabbits 
(2.77 ±0.05 kg) were anesthetized, tracheos- 
tomized, and intubated with several different 
sizes of endotracheal tubes (ETT) (2.0, 2.5, 3.0, 
3.5, or 4.0 mm i.d.). The animals were para- 
lyzed and ventilated (Siemens Servo 9(K)C). 
Baseline ventilator settings were at a rate of 
50/min, inspiratory:expiratory (I:E) ratio of 2:1 
or 4: 1 , and minute ventilation was manipulated 
to create 3 or 5 cm HjG PEEPi-stat. PEEPi-stat 
was measured using the expiratory hold button 
of the ventilator. PEEPi-dyn showed large vari- 
ations. In all ventilator settings, PEEPi-dyn was 
higher than PEEPi-stat (p < 0.001). The larger 
the ETT, the higher the PEEPi-dyn at an l:E 
ratio of 2:1 (p < 0.05). The higher the minute 
ventilation, the greater the difference between 
PEEPi-stat and PEEPi-dyn. The tidal volume 
and the difference showed a significant corre- 
lation (r^ = 0.514, p < 0.001). CONCLU- 
SIONS: The value of PEEPi-dyn was depen- 
dent on ventilatory settings, and PEEPi-dyn does 
not necessarily represent (he lowest regional 
PEEPi within the lungs. 

Bronchodilator Delivered by Metered Dose 
Inhaler and Spacer Improves Respiratory 
System Compliance More Than Nebulizer- 
Delivered Bronchodilator in Ventilated Pre- 
mature Infants — Sivakumar D. Bosque E. 
Goldman SL.PediatrPulmonoll 999 Mar;27(3): 

We compared the change in passive respiratory 
system compliance (Crs) and resistance (Rrs) 
after albuterol aerosol treatment administered 
by either low-flow nebulizer (NEB) or a me- 
tered dose inhaler (MDl) and spacer into a ven- 
tilator circuit. We hypothesized that albuterol 
delivered to ventilated infants older than 7 days 
of life by an MDI and a spacer would improve 
Crs more than albuterol delivered by a low- 
flow nebulizer. The treatments were adminis- 
tered 6 hr apart to premature infants with Crs £ 
0.8 mL/cm H2O per kg, requiring ventilation 
after 7 days of age. Patients served as their own 
controls and treatment order was randomized. 
Eighteen studies were performed in eight in- 
fants before and 1 and 3 hr after treatment. 

Differences between methods were compared 
by analyses of variance. Mean (range) birth 
weight and study age were 888 (619-1,283) g 
and 12 (7-29) days, respectively. Mean respi- 
ratory system compliance increased by 34% with 
MDI and by 1 1 % with NEB at 1 hr after treat- 
ment (p < 0.02). By 3 hr after treatment, Crs 
returned to baseline with both methods of aero- 
sol delivery. There was no significant differ- 
ence in Rrs between the two methods at 1 and 
3 hr after treatment. We conclude that albuterol 
delivered by MDI improves Crs more than low- 
tlow NEB in ventilated premature infants. 

Effect of Neck Position on Endotracheal Tube 
Location in Low Birth Weight Infants — Rost 
JR, Frush DP, Auten RL. Pediatr Pulmonol 1999 

Mar:27(3): 199-202. 

Neck position can affect the position of the tip 
of the endotracheal tube (ETT) in normal neo- 
nates; this has not been .systematically investi- 
gated in low birth weight (LBW) neonates. It 
was our intention to determine the effect of 
neck flexion and extension on ETT position in 
LBW infants. Eight LBW orotracheally-intu- 
bated infants underwent postmortem anteropos- 
terior chest radiographs with the neck in a neu- 
tral position, in 55 degrees flexion, and in 55 
degrees extension. Measurements from the tho- 
racic inlet to the ETT were obtained in each 
position. The ETT always moved caudad with 
neck flexion (p = 0.001) and cephalad with 
neck extension (p = 0.001 ). The mean extent of 
ETT displacement was 3. 1 mm (SD, 1 .7 mm) 
with neck flexion, and 7.4 mm (SD, 5.2 mm) 
with extension (p < 0.05). We conclude that in 
LBW infants: 1) the direction of ETT move- 
ment with neck flexion and extension is pre- 
dictable and identical to that seen in term in- 
fants and children, and 2) neck flexion should 
not be a principal consideration in management 
of ETT location. 

Cost Reduction and Outcome Improvement 
in the Intensive Care Unit — Marx WH, De- 
Maintenon NL, Mooney KF, Mascia ML, Medi- 
cis J. Franklin PD, et al. J Trauma 1999 Apr: 
46(4):625-629; discussion 629-630. 

OBJECTIVE: Decreasing reimbursement pro- 
vided by third-party payors necessitates reduc- 
tion of costs for providing critical care services. 
If academic medical centers are to remain via- 
ble, methods must be instituted that allow cost 
reduction through practice change. METHODS: 
We used short cycle improvement methodol- 
ogy to rapidly achieve these goals. Short cycle 
improvement methodology involves identifying 
the areas for improvement, defining a mecha- 
nism to evaluate outcome, initiating an improve- 
ment plan on a small number of patients, and 
repeating the cycle with new adjustments based 
on outcome. Baseline data on areas for improve- 
ment was prospectively collected, and proto- 

cols to initiate change were developed and tested 
by short improvement cycles. Outcomes were 
evaluated, protocols were modified, and another 
cycle was performed. This methodology was 
continued until the desired goals had been 
achieved. To adjust outcomes for severity of 
illness. Acute Physiology and Chronic Health 
Evaluation II methodology was used. Using this 
methodology, we focused on three areas for 
improvement. Standing orders for laboratory 
studies, electrocardiograms, and chest x-ray 
films were eliminated. Protocols were devel- 
oped for the appropriate use of sedation, anal- 
gesics, and neuromuscular blocking agents. Fi- 
nally, a protocol for weaning from mechanical 
ventilation was developed to allow respiratory 
therapists to proceed through the weaning pro- 
cess, which was ordered by a physician. RE- 
SULTS: Laboratory tests were reduced by 65% 
(from 510 to 180 tests per day) with an annual 
cost .savings of $21,593. Chest x-ray reduction 
of 56% resulted in an annual savings of $3,941. 
There was a 75% reduction in cost of neuro- 
muscular blocking agents. The use of neuro- 
muscular blocking agents resulted in a 75% re- 
duction in drug costs. Ventilator hours were 
reduced by 35% from 140 to 90 hours. The 
average length of overall intensive care unit 
stay was reduced by 1.5 days (5.0 to 3.5 days). 
The cost per patient day decreased with an an- 
nualized cost savings of 4% per patient day. 
Unexpected outcomes included a reduction in 
intensive care unit days from 54 days at base- 
line to 7 days at the 6-month interval. The in- 
fection rates for blood stream infections, uri- 
nary tract infections, and nosocomial pneumonia 
were reduced. Using national nosocomial in- 
fection data, these rates represented a reduction 
from the fiftieth percentile to the twenty-fifth 
percentile for all measured indicators. Acute 
Physiology and Chronic Health Evaluation II 
scores were 19.54 at baseline and increased to 
21.2 (p = 0.001) at the 6-month interval. Mor- 
tality rates were 16.7% at baseline and were 
17.6% (p = 0.89) at the 6-month interval. CON- 
CLUSION: We concluded that utilization of 
short cycle improvement methodology provided 
an ongoing method for reducing costs of criti- 
cal care services in our patient population with 
no change in mortality. 

Extracorporeal Life Support in Pulmonary 
Failure After Trauma — Michaels AJ, Schrie- 
ner RJ, Kolla S, Awad SS, Rich PB, Reickert C, 
et al. J Trauma 1999 Apr;46(4):638-645. 

OBJECTIVE: To present a series of 30 adult 
trauma patients who received extracorporeal life 
support (ECLS) for pulmonary failure and to 
retrospectively review variables related to their 
outcome. METHODS: In a Level I trauma cen- 
ter between 1989 and 1997, ECLS with contin- 
uous heparin anticoagulation was instituted in 
30 injured patients older than 15 years. Indica- 
tion was for an estimated mortality risk greater 

Respiratory Care • July 1999 Vol 43 No 7 


than 80%, defined by a PaOj-FiOj ''^tio 'ess than 
100 on 100% FiQj, despite pressure-mode in- 
verse ratio ventilation, optimal positive end-ex- 
piratory pressure, reasonable diuresis, transfu- 
sion, and prone positioning. Retrospective 
analysis included demographic information 
(age, gender. Injury Severity Score, injury mech- 
anism), pulmonary physiologic and gas-ex- 
change values (pre-ECLS ventilator days 
[VENT days], PaOj'FiOj ratio, mixed venous ox- 
ygen saturation [S^.oJ, and blood gas), pre- 
ECLS cardiopulmonary resuscitation, compli- 
cations of ECLS (bleeding, circuit problems, 
leukopenia, infection, pneumothorax, acute re- 
nal failure, and pressors on ECLS), and sur- 
vival. RESULTS: The subjects were 26.3±2.1 
years old (range, 15-59 years), 50% male, and 
had blunt injury in 83.3%. Pulmonary recovery 
sufficient to wean the patient from ECLS oc- 
curred in 17 patients (56.7%), and 50% sur- 
vived to discharge. Fewer VENT days and more 
normal S^qj *^''s associated with survival. The 
presence of acute renal failure and the need for 
venoarterial support (venoarterial bypass) were 
more common in the patients who died. Bleed- 
ing complications (requiring intervention or ad- 
ditional transfusion) occurred in 58.6% of pa- 
tients and were not associated with mortality. 
Early use of ECLS (VENT days £ 5) was as- 
sociated with an odds ratio of 7.2 for survival. 
Fewer VENT days was independently associ- 
ated with survival in a logistic regression model 
(p = 0.029). Age, Injury Severity Score, and 
faOj'PiOi ■'a''" ^^■'^ ""' related to outcome. 
CONCLUSION: ECLS has been safely used in 
adult trauma patients with multiple injuries and 
severe pulmonary failure. In our series, early 
implementation of ECLS was associated with 
improved survival. Although this may repre- 
sent selection bias for less intractable forms of 
acute respiratory distress syndrome, it is our 
experience that early institution of ECLS may 
lead to improved oxygen delivery, diminished 
ventilator-induced lung injury, and improved 

Kinetics of Absorption Atelectasis During 
Anesthesia: A Mathematical Model — Joyce 
CJ, Williams AB. J Appl Physiol 1999 Apr; 

Recent computed tomography studies show that 
inspired gas composition affects the develop- 
ment of anesthesia-related atelectasis. This sug- 
gests that gas absorption plays an important role 
in the genesis of the atelectasis. A mathemati- 
cal model was developed that combined models 
of gas exchange from an ideal lung compart- 
ment, peripheral gas exchange, and gas uptake 
from a closed collapsible cavity. It was assumed 
that, initially, the lung functioned as an ideal 
lung compartment but that, with induction of 
anesthesia, the airways to dependent areas of 
lung closed and these areas of lung behaved as 
a closed collapsible cavity. The main parameter 

of interest was the time the unventilated area of 
lung took to collapse; the effects of preoxygen- 
ation and of different inspired gas mixtures dur- 
ing anesthesia were examined. Preoxygenation 
increased the rate of gas uptake from the un- 
ventilated area of lung and was the most im- 
portant determinant of the time to collapse. In- 
creasing the inspired Oj fraction during 
anesthesia reduced the time to collapse. Which 
inert gas (Nj or NjO) was breathed during an- 
esthesia had minimal effect on the time to col- 
lapse. See the related editorial: Kinetics of Ab- 
sorption Atelectasis During Anesthesia: A 
Mathematical Model. Hedenstierna G. J Appl 
Physiol 1999 Apr:86(4):l 114-1115. 

Pulmonary Perfusion Is More Uniform in the 
Prone Than in the Supine Position: Scintig- 
raphy in Healthy Humans — Nyren S, Mure 
M, Jacobsson H, Larsson S A, Lindahl SG. J Appl 
Physiol 1999 Apr;86(4):l 135-1 141. 

The main purpose of this study was to find out 
whether the dominant dorsal lung perfusion 
while supine changes to a dominant ventral lung 
perfusion while prone. Regional distribution of 
pulmonary blood flow was determined in 10 
healthy volunteers. The subjects were studied 
in both prone and supine positions with and 
without lung distension caused by 10 cm HjO 
of continuous positive airway pressure (CPAP). 
Radiolabeled macroaggregates of albumin, 
rapidly trapped by pulmonary capillaries in pro- 
portion to blood flow, were injected intrave- 
nously. Tomographic gamma camera examina- 
tions (single-photon-emission computed 
tomography) were performed after injections in 
the different positions. All data acquisitions were 
made with the subject in the supine position. 
CPAP enhanced perfusion differences along the 
gravitational axis, which was more pronounced 
in the supine than prone position. Diaphrag- 
matic sections of the lung had a more uniform 
pulmonary blood flow distribution in the prone 
than supine position during both normal and 
CPAP breathing. It was concluded that the dom- 
inant dorsal lung perfusion observed when the 
subjects were supine was not changed into a 
dominant ventral lung perfusion when the sub- 
jects were prone. Lung perfusion was more uni- 
formly distributed in the prone compared with 
in the supine position, a difference that was 
more marked during total lung distension 
(CPAP) than during normal breathing. 

Multicentre Randomised Controlled Trial of 
Nursing Intervention for Breathlessness in 
Patients with Lung Cancer — Bredin M, Cor- 
ner J, Krishnasamy M, Plant H, Bailey C, 
A'Hem R. BMJ 1999 Apr 3;318(7188):901- 

OBJECTIVE: To evaluate the effectiveness of 
nursing intervention for breathlessness in pa- 
tients with lung cancer. DESIGN: Patients di- 

agnosed with lung cancer participated in a mul- 
ticentre randomised controlled trial where they 
either attended a nursing clinic offering inter- 
vention for their breathlessness or received best 
supportive care. The intervention consisted of a 
range of strategies combining breathing con- 
trol, activity pacing, relaxation techniques, and 
psychosocial support. Best supportive care in- 
volved receiving standard management and 
treatment available for breathlessness, and 
breathing assessments. Participants completed 
a range of self assessment questionnaires at base- 
line, 4 weeks, and 8 weeks. SETTING: Nursing 
clinics within 6 hospital settings in the United 
Kingdom. PARTICIPANTS: 119 patients diag- 
nosed with small cell or non-small cell lung 
cancer or with mesothelioma who had com- 
pleted first line treatment for their disease and 
reported breathlessness. OUTCOME MEA- 
SURES: Visual analogue scales measuring dis- 
tress due to breathlessness, breathlessness at best 
and worst, WHO performance status scale, hos- 
pital anxiety and depression scale, and Rotter- 
dam symptom checklist. RESULTS: The inter- 
vention group improved significantly at 8 weeks 
in 5 of the 1 1 items assessed: breathlessness at 
best, WHO performance status, levels of de- 
pression, and two Rotterdam symptom check- 
list measures (physical symptom distress and 
breathlessness) and showed slight improvement 
in 3 of the remaining 6 items. CONCLUSION: 
Most patients who completed the study had a 
poor prognosis, and breathlessness was typi- 
cally a symptom of their deteriorating condi- 
tion. Patients who attended nursing clinics and 
received the breathlessness intervention expe- 
rienced improvements in breathlessness, per- 
formance status, and physical and emotional 
states relative to control patients. 

Effects of Ventilator Resetting on Indirect 
Calorimetry Measurement in the Critically 
III Surgical Patient— Brandi LS, Bertolini R, 
Santini L, Cavani S. Crit Care Med 1999 Mar; 

27(3):53 1-539. 

OBJECTIVE: To evaluate the effect of acute 
changes in minute ventilation (Vg) on oxygen 
consumption (Vq^, carbon dioxide production 
(Vc-oj). respiratory quotient, and energy expen- 
diture during volume-controlled mechanical 
ventilation in the critically ill surgical patient. 
The effects on some oxygen transport variables 
were assessed as well. DESIGN: Prospective, 
randomized clinical study SETTING: Adult sur- 
gical intensive care unit of a university teaching 
hospital. PATIENTS: Twenty adult critically ill 
surgical patients were studied during volume- 
controlled mechanical ventilation. INTERVEN- 
TIONS: After a basal period of stability (no 
changes over time in body temperature, energy 
expenditure, blood gases, acid-base status, car- 
diac output, and ventilatory parameters), Vg was 
then randomly either increased or reduced 
( ± 35%) by a change in tidal volume ( Vj), while 


Respiratory Care • July 1999 Vol 43 No 7 

respiratory rale and inspiratory/expiratory ratio 
were kept constant. Settings were then main- 
tained for 120 mins. During the study, patients 
were sedated and paralyzed. MEASURE- 
and respiratory quotient were measured contin- 
uously by a Nellcor Puritan Bennett 7250 met- 
abolic monitor (Nellcor Puritan Bennett, Carls- 
bad, CA). Hemodynamic and oxygen transport 
parameters were obtained every 15 mins during 
the study. Despite large changes in V^, Vq, and 
energy expenditure did not change significantly 
either in the increased or in the reduced Vg 
groups. After 15 mins. V^o, and respiratory 
quotient changed significantly after ventilator 
resetting. V(~„, increased by 10.5 ± 1.1% (from 
2.5 ±0.10 to 2.8 ± 0.12 mLymin/kg,p< 0.01) 
in the increased Vp; group and decreased by 
12.4 ± 2.1% (from 2.7 ± 0.17 to 2.4 ± 0.16 
mL/min/kg, p< 0.01) in the reduced V,, group. 
Similarly, respiratory quotient increased by 
16.2% ± 2.2% (from 0.87 ± 0.02 to 1.02 ± 
0.02, p < 0.01) and decreased by 17.2% ± 
1.8% (from 0.88 ± 0.02 to 0.73 ± 0.02, p < 
0.01 ). V|-.„, normalized in the reduced Vp group, 
but remained higher than baseline in the in- 
creased V|.; group. Respiratory quotient did not 
normalize in both groups and remained signif- 
icantly different from baseline at the end of the 
study. Cardiac index, oxygen delivery, and 
mixed venous oxygen saturation increased, 
while oxygen extraction index decreased sig- 
nificantly in the reduced Vg group. Neither of 
the mentioned parameters changed significantly 
in the increased V^ group. CONCLUSIONS; 
We conclude that, during controlled mechani- 
cal ventilation, the time course and the magni- 
tude of the effect on gas exchange and energy 
expenditure measurements caused by acute 
changes in Vp suggest that V^, and energy ex- 
penditure measurements can be used reliably to 
evaluate and quantify metabolic events and that 
V(.(,, and respiratory quotient measurements are 
useless for metabolic purposes at least for 120 
mins after ventilator resetting. See the related 
editorial: Effects of Ventilator Resetting on 
Indirect Calorimetry Measurement: The Im- 
portance of Patience. Kirkland L. Crit Care 
Med 1999 Mar:27(3):459-460. 

Pulmonary Function Monitoring During 
Adenosine Myocardial Perfusion Scintigra- 
phy in Patients with Chronic Obstructive Pul- 
monary Disease — Johnston DL, Scanlon PD, 
Hodge DO, Glynn RB, Hung JC, Gibbons RJ. 
Mayo Clin Proc 1999 Apr;74(4);339-346. 

OBJECTIVE: To determine whether adenosine 
could be safely administered to patients with 
chronic obstructive pulmonary disease (COPD) 
lor coronary vasodilatation during perfusion 
scintigraphy without causing bronchospasm. 
divided into two phases. In the monitoring phase, 
patients with COPD were pretreated with an 




principles and applications 
8th Annual Course 

• Highlights of recent developments 
"Hands-on" small group workshops 
• Close faculty interaction 
• Intensive tutorials 

September 16-19, 1999 

Minneapolis, Minnesota, USA 

Course director: John Marini, MD 
Guest lecturers: 

Richard Albert, MD 
Marcelo Amato, MD 
Lluis Blanch, MD 
Richard Branson, RRT 
John Downs, MD 

Dean Hess, PhD, RRT 
Giorgio lotti, MD 
Nicholas Hill, MD 
Robert Kacmarek, PhD, RRT 
David Pierson, MD 

For further information, contact Continuing Medical Education, 

University of Minnesota, 107 Radisson Hotel Metrodome, 

615 Washington Avenue SE, Minneapolis, Minnesota 55414 (USA) 

Telephone (612)626-7600: FAX: (612)626-7766 

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inhaled bronchodilator (albuterol) and had pul- 
monary function monitored during the infusion 
of a graduated dose of adenosine. Eligibility for 
entry into this phase of the study was deter- 
mined on the basis of results of pulmonary func- 
tion testing (PPT) during resting. Once we had 
shown that adenosine could be safely adminis- 
tered to patients with COPD, an implementa- 
tion phase was begun. Entry did not require 
resting PFT, and patients were administered 
adenosine without monitoring of pulmonary 
function. Differences between patients with nor- 
mal pulmonary function or mild COPD and those 
with more severe COPD were analyzed statis- 
tically. RESULTS: Of 94 patients entered into 
the monitoring phase, none had obvious bron- 
chospasm. The dosage of adenosine was re- 
duced in four patients because of a decrease in 
forced expiratory volume in 1 second (FEV,) 
of 20% in comparison with baseline (FEV, be- 
fore administration of albuterol). The mean 
FEV, decrea.sed slightly from 1.83 L after ad- 
ministration of albuterol to 1.78 L during the 
maximal adenosine dose. Patients with a re- 
mote history of asthma, positive result of a 
methacholine challenge test, or mild COPD 
(FEV I 60 to 80% of the maximal predicted value 
for age) did not differ significantly in their re- 
sponse to infusion of adenosine from those with 
moderate or severe COPD (FEV, 30 to 59% of 
the maximum predicted for age). Of 117 pa- 

tients in the implementation phase, 2 had bron- 
chospasm during infusion of adenosine that was 
quickly terminated by stopping the administra- 
tion in one patient and reducing the dose of 
adenosine in the other. CONCLUSION: This 
study shows that adenosine can be safely ad- 
ministered intravenously to selected patients 
with known or suspected COPD to produce cor- 
onary vasodilatation for myocardial perfusion 
imaging. Patients who are within the guidelines 
established for this study should be considered 
for adenosine coronary vasodilatation with use 
of bronchodilator pretreatment, a graduated dose 
of adenosine, and regular chest auscultation dur- 
ing the infusion. 

Adult Immunizations: Recommendations for 

Practice— Reid KC, Grizzard TA, Poland GA. 
Mayo Clin Proc 1999 Apr:74(4):377-384. 

Each year in the United States, 50,000 to 90,000 
adults die of pneumococcal disease, influenza, 
and hepatitis infections. These figures vastly 
exceed mortality due to vaccine-preventable dis- 
eases in children. In addition, adult immuniza- 
tions are cost-effective and lifesaving measures. 
Nonetheless, surveys reveal that both physicians 
and patients underuse adult immunizations as 
an effective means of disease prevention. The 
goal of achieving higher adult immunization 
rates is critically dependent on improving the 

Respiratory Care • July 1999 Vol 43 No 7 



attitudes and practices of health-care providers. 
In this article, we review several vaccines rou- 
tinely used in the practice of adult medicine. 

Hyperbaric Oxygen Therapy for Massive Ar- 
terial Air Embolism During Cardiac Oper- 
ations — Ziser A, Adir Y, Lavon H, Shupak A. 
J Thorac Cardiovasc Surg 1999 Apr;117(4): 

BACKGROUND: Massive arterial air embo- 
lism is a rare but devastating complication of 
cardiac operations. Several treatment modali- 
ties have been proposed, but hyperbaric oxygen 
is the specific therapy. METHODS: The Israel 
Naval Medical Institute is the only referral hy- 
perbaric center in this country for acute care 
patients. We reviewed our experience in the 
hyperbaric oxygen treatment of massive arterial 
air embolism during cardiac operations. RE- 
SULTS: Seventeen patients were treated be- 
tween 1985 and 1998. Eight patients (47.1%) 
experienced a complete neurologic recovery; 6 
patients (35.3%) remained unconscious at dis- 
charge, and 3 patients (17.6%) died. Mean (± 
SD) delay from the end of the operation to hy- 
perbaric therapy was 9.6 ±7.4 hours (range, 
1-20 hours). This delay was 4.0 ± 3.4 hours 
(1-12 hours) for patients who had a full neu- 
rologic recovery, 12.8 ± 7.1 hours (5-20 hours) 
for patients with severe neurologic disability, 
and 18.0 ± 2.0 hours (16-20 hours) for pa- 
tients who died (1-way analysis of variance; 
p = 0.002). The source of variance among the 
groups mainly resulted from the short delay for 
patients who experienced complete recovery 
compared with the other 2 groups (Tukey test). 
All 5 patients who were treated within 3 hours 
from the operation and 50% (2 of 4 patients) of 
those patients treated 3 to 5 hours from opera- 
tion experienced a full neurologic recovery. 
With a delay of 9 to 20 hours, only 1 of 8 
patients had a full neurologic recovery. The as- 
sociation between outcome and treatment de- 
lay was found to be statistically significant (T 
= 0.65 with exact 2-sided p value = 0.0007). 
CONCLUSION: Hyperbaric oxygen therapy 
should be administered as soon as possible after 
massive arterial air embolism during cardiac 

Prospective Multicenter Study of Relapse 
Following Treatment for Acute Asthma 
Among Adults Presenting to the Emergency 
Department. MARC Investigators. Multi- 
center Asthma Research Collaboration. 
Emerman CL, Woodruff PG, Cydulka RK, 
Gibbs MA, Pollack CV Jr, Camargo CA Jr. 
Chest 1999 Apr;115(4):919-927. 

STUDY OBJECTIVE: To identify factors as- 
sociated with relapse following treatment for 
acute asthma among adults presenting to the 
emergency department (ED). DESIGN: Pro- 
spective inception cohort study performed dur- 

ing October 1996 to December 1996 and April 
1997 to June 1997, as part of the Multicenter 
A.sthma Research Collaboration. SETTING: 
Thirty-six EDs in 18 states. PATIENTS: ED 
patients, aged 18 to 54 years, with physician 
diagnosis of acute asthma. For the present anal- 
ysis, we restricted the cohort to patients sent 
home from the ED (n = 971), then further ex- 
cluded patients with comorbid respiratory con- 
ditions (n = 32). This left 939 eligible subjects 
to have follow-up data. Interventions: None. 
weeks after being sent home from the ED, pa- 
tients were contacted by telephone. A relapse 
was defined as an urgent or unscheduled visit to 
any physician for worsening asthma symptoms 
during the 14-day follow-up period. Complete 
follow-up data were available for 641 patients, 
of whom 17% reported relapse (95% confidence 
interval, 14 to 20). There was no significant 
difference in peak expiratory flow rate (PEER) 
between patients who suffered relapse and those 
who did not. In a multivariate logistic regres- 
sion analysis (controlling for age, gender, race, 
and primary care provider status), patients who 
suffered relapse were more likely to have a his- 
tory of numerous ED (odds ratio [OD] 1.3 per 
5 visits) and urgent chnic visits (OR 1.4 per 5 
visits) for asthma in the past year, use a home 
nebulizer (OR 2.2), report multiple triggers of 
their asthma (OR 1 . 1 per trigger), and report a 
longer duration of symptoms (OR 2.5 for 1 to 7 
days). CONCLUSION: Among patients sent 
home from the ED following acute asthma ther- 
apy, 17% will have a relapse and PEER does 
not predict who will develop this outcome. By 
contrast, several historical features were asso- 
ciated with increased risk. Further research 
should focus on ways to decrease the relapse 
rate among these high-risk patients. The clini- 
cian may wish to consider these historical fac- 
tors when making ED decisions. See the related 
editorial: Emergency Department Care of the 
Asthma Patient: Predicting "Bounce-Back" 
Patients. Varon J, Fromm RE Jr. Chest 1999 

Effect of Continuously Nebulized Ipratro- 
pium Bromide Plus Albuterol on Emergency 
Department Length of Stay and Hospital Ad- 
mission Rates in Patients with Acute Bron- 
chospasm: A Randomized, Controlled Tri- 
al — Weber EJ, Levitt MA, Covington JK, 
Gambrioli E. Chest 1999 Apr;l 15(4):937-944. 

OBJECTIVE: To compare the outcome of pa- 
tients with acute bronchospasm treated with con- 
tinuously nebulized albuterol plus ipratropium 
bromide vs albuterol alone. SETTING: The 
Emergency Department (ED) at the University 
of California San Francisco Medical Center. 
PARTICIPANTS: Patients > 18 years old pre- 
senting to the ED with acute bronchospasm and 
a peak expiratory flow rate (PEER) of < 70% 
predicted. INTERVENTIONS: This was a pro- 

spective, randomized, double-blind, placebo- 
controlled trial. Subjects were treated with ei- 
ther a combination of albuterol (10 mg/h) plus 
ipratropium bromide (1.0 mg/h) or albuterol 
alone via continuous nebulization for a maxi- 
mum of 3 h. Vital signs, Borg dyspnea score, 
and PEER were recorded hourly. Primary out- 
come measures were improvement in PEFR, 
hospital admission rates, and length of stay in 
Data was analyzed for 67 subjects. The mean 
age (± SD) was 47.5 ±18.8, and mean initial 
PEFR was 44.8± 12.5% of predicted. The me- 
dian length of stay for all subjects was 225 min, 
and 31% of all subjects were admitted. Patients 
given combination therapy averaged 6.3% 
greater improvement in PEFR compared with 
control subjects (95% confidence interval [CI], 
-15% to 27%. The odds ratio for admission 
with combination therapy was 0.88 (95% CI, 
0.28 to 2.8). The median length of stay in the 
ED was 35 min shorter for those receiving com- 
bination treatment (210 vs 245 min; p = 0.03). 
However, when adjusted for initial PEFR, there 
was no statistically significant difference (p = 
0.26). CONCLUSION: Although the direction 
of all three outcome measures favored combi- 
nation therapy, there was no statistically signif- 
icant difference between ED patients with acute 
bronchospasm receiving continuous albuterol 
plus ipratropium bromide and those receiving 
albuterol alone. See the related editorial: Bron- 
chodilator Therapy in Status Asthmaticus. Tee- 
ter JG. Chest 1999 Apr;115(4):91 1-912. 

The Laboratory-Clinical Interface: Point-of- 
Care Testing— Kost GJ, Ehrmeyer SS, Cher- 
now B, Winkelman JW, Zaloga GP, Dellinger 
RP, Shirey T. Chest 1999 Apr;l 15(4):1 140- 

POC testing provides an opportunity for clini- 
cians and laboratorians to work together to con- 
sider how best to serve the patients within an 
individual institution. Each health system has 
unique characteristics relative to patient popu- 
lation, as well as a unique laboratory structure. 
If physicians, nurses, laboratorians, and pathol- 
ogists work collaboratively, the best interests of 
patients will be served. In some institutions that 
cater to specific patient groups, POC testing 
may offer clear and distinct advantages. In other 
institutions with sophisticated transport systems 
and established rapid response capabilities, the 
quality resulting from central laboratory testing 
may outweigh any advantages of bedside test- 
ing. Clearly, attention to regulatory issues, QC 
issues, the importance of proper documenta- 
tion, proficiency testing, performance enhance- 
ment, and cost-effectiveness is requisite. As the 
technology for diagnostic testing advances 
through more microcomputerization, micro- 
chemistry, and enhanced test menus, the con- 
cept of POC testing will need perpetual revis- 
iting. We hope that the information provided 


Respiratory Care • July 1999 Vol 43 No 7 


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ministrators in their quest to best serve their 
patients. See the related editorial: Point-of-Care 
Blood Testing: More Than Simply Changing 
Venue. Shapiro BA. Chest 1999 Apr: 115(4): 

The Clinical Utility of Invasive Diagnostic 
Techniques in the Setting of Ventilator-As- 
sociated Pneumonia. Canadian Critical Care 
Trials Group— Heyland DK, Cook DJ, Mar- 
shall J, Heule M, Guslits B, Lang J, Jaeschke R. 
Chest 1999 Apr;l 15(4): 1076-1084. 

OBJECTIVE: To evaluate the clinical utility of 
bronchoscopy with protected brush catheter 
(PBC) and BAL for patients with ventilator- 
associated pneumonia (VAP). DESIGN: Pro- 
spective cohort study. SETTING: Ten tertiary 
care ICUs in Canada. PATIENTS: Ninety-two 
mechanically ventilated patients with a clinical 
suspicion of VAP who underwent bronchos- 
copy were compared with 49 patients with a 
clinical suspicion of pneumonia who did not. 
MENTS AND RESULTS: We compared anti- 
biotic use, duration of mechanical ventilation, 
ICU stay, and mortality. In addition, for pa- 
tients who received bronchoscopy, we admin- 
istered a questionnaire (before and after bron- 
choscopy) to evaluate the effect of PBC or BAL 
on (I) physician perception of the probability 
of VAP, (2) physician confidence in the diag- 
nosis of VAP, and (3) changes to antibiotic 
management. After bronchoscopy results be- 
came available, from the physician's perspec- 
tive, the diagnosis of VAP was deemed much 
less likely (p < 0.001), confidence in the diag- 
nosis increased (p = 0.03), and level of comfort 
with the management plan increased (p = 0.02). 
Following the results of invasive diagnostic 
tests, in the group that underwent bronchos- 
copy, patients were receiving fewer antibiotics 
(31/92 vs 9/49, p = 0.05) and more patients had 
treatment with all their antibiotics discontinued 
(18/92 vs 3/49, p = 0.04) compared with the 
group that did not undergo bronchoscopy. Du- 
ration of mechanical ventilation and ICU stay 
were similar between the two groups, but mor- 
tality was lower in the group that underwent 
bronchoscopy with PBC or BAL (18.5% vs 
34.7%, p = 0.03). CONCLUSIONS: Invasive 
diagno.stic testing may increase physician con- 
fidence in the diagnosis and management of 
VAP and allows for greater ability to limit or 
discontinue antibiotic treatment. Whether per- 
forming PBC or BAL affects clinically impor- 
tant outcomes requires further study. See the 
related editorial: Not a Matter of Life and 
Death! Johanson WG Jr. Che.\t 1999 Apr; 

Safety of Long-Term Treatment with HFA 
Albuterol— Ramsdell JW, Klinger NM, Ek- 

holm BP, Colice GL. Chest 1999 Apr;l 15(4): 

BACKGROUND: Chlorofluorocarbons (CFCs) 
used as propellants in metered-dose inhalers de- 
plete stratospheric ozone, which results in se- 
rious public health concerns. Albuterol has been 
reformulated in the non-ozone-depleting pro- 
pellant, hydrofluoroalkane-134a (HFA albu- 
terol). OBJECTIVES: The primary objective 
was to compare the safety of HFA albuterol to 
an albuterol product formulated in chlorofluo- 
rocarbon propellants (CFC albuterol) during 1 
year of treatment in asthmatics. Bronchodilator 
efficacy of the two products was assessed as a 
secondary objective. METHODS: The results 
from two open-label, parallel-group trials of sim- 
ilar design in asthmatics requiring short-acting 
beta-agonists for symptom control were com- 
bined. Patients took two puffs bid of either HFA 
albuterol or CFC albuterol for I year. Addi- 
tional puffs of study drug were allowed as needed 
to control asthma symptoms. Adverse events 
were recorded at clinic visits. Patients self-ad- 
ministered study drug at quarteriy visits and 
underwent serial spirometry during a 6-h period 
postdose. Bronchodilator efficacy variables, 
based on FEV, to study drug, were 
proportion of responders, time to onset of ef- 
fect, peak percent change, time to peak effect, 
duration of effect, and area under the curve. 
Differences between products and changes over 
time in efficacy variables were assessed using 
an analysis of variance model. Regression anal- 
yses with FEV, as a covariate were performed 
post-hoc to analyze changes in bronchodilator 
efficacy over time. RESULTS: Demographic 
and baseline characteristics were similar for pa- 
tients receiving HFA albuterol (n = 337) and 
CFC albuterol (n = 132). Total reported ad- 
verse events were similar for the two treatments. 
Differences in only four individual adverse 
events were noted: the HFA albuterol group 
reported more gastroenteritis and dizziness; the 
CFC albuterol group reported more epistaxis 
and expectoration. Adverse events attributed to 
study drug use were infrequent. No serious ad- 
verse events were related to study drug use. 
Predose FEV, at quarterly visits increased to a 
small extent in both groups from month to 
month 12. The bronchodilator efficacy of HFA 
albuterol was comparable to that of CFC albu- 
terol at the quarteriy visits, but decreased from 
baseline for both products over the 12 months 
of treatment. Use of inhaled corticosteroids, na- 
sal corticosteroids, or theophylline did not ex- 
plain the increase in predose FEV, over time 
and did not protect patients from developing 
reduced bronchodilator efficacy by month 12. 
The change in predose FEV, did not entirely 
account for the reduced bronchodilator efficacy 
over time. CONCLUSIONS: HFA albuterol has 
a safety profile similar to that of CFC albuterol 
during chronic, scheduled, and both drugs 
are well tolerated. HFA albuterol and CFC al- 

buterol provided comparable bronchodilator ef- 
ficacy, but bronchodilator efficacy decreased 
for both products with I year of use. 

Clickhaler (A Novel Dry Powder Inhaler) 
Provides Similar Bronchodilation to Pressur- 
ized Metered-Dose Inhaler, Even at Low 
Flow Rates— Newhouse MT, Nantel NP, 
Chambers CB, Pratt B, Parry-Billings M. Chest 
1999 Apr;ll5(4):952-956. 

STUDY OBJECTIVE: Comparison of the bron- 
chodilator response to an albuterol novel dry 
powder inhaler (DPI) (Clickhaler |CH]; ML 
Laboratories PLC; St. Albans, UK) activated at 
various inspiratory flow rates and to an albu- 
terol pressurized metered-dose inhaler (pMDI) 
by patients with moderate to moderately severe 
stable a.sthma. DESIGN: Randomized, double- 
blind, placebo-controlled comparison of the 
bronchodilator response to albuterol DPI (200 
microg) at inspiratory flow rates of approxi- 
mately 15, 30, and 60 L/min in patients with 
.stable a.sthma with demonstrated reversibility 
to albuterol. Active (albuterol via pMDI inhaled 
at 30 L/min) and placebo controls were included. 
SETTING: Single center study at the chest/al- 
lergy unit of a teaching hospital in Canada. PA- 
TIENTS: Sixteen patients with moderate to 
moderately severe stable asthma. MEASURE- 
MENTS AND RESULTS: Efficacy end points 
were FEV,, FVC, FEV,/FVC. maximum expi- 
ratory flow, and forced expiratory flow between 
25% and 75% of vital capacity. Safety end points 
included heart rate, BP, and tremor. There was 
no significant difference between the broncho- 
dilator response to albuterol via the CH at 15, 
30, and 60 L/min inspiratory flow rate and, at 
all flow rates, no significant difference was 
found comparing albuterol CH with the pMDI. 
All of the techniques for delivering albuterol 
provided significantly better bronchodilatation 
than placebo. Adverse events were minimal and 
did not differ between CH and pMDI or be- 
tween the various flow rates inhaled through 
the CH. CONCLUSION: A novel passive al- 
buterol DPI (CH) provides a similar broncho- 
dilator response at 15, 30, and 60 L/min in- 
spiratory flow rates compared with a pMDI used 

Efficacy of Salmeterol Xinafoate in the Treat- 
ment of COPD— Mahler DA, Donohue JF, Bar- 
bee RA, Goldman MD, Gross NJ, Wisniewski 
ME, et al. Chest 1999 Apr; 1 15(4):957-965. 

STUDY OBJECTIVES: To examine and com- 
pare the efficacy and safety of salmeterol xin- 
afoate, a long-acting inhaled beta2-adrenergic 
agonist, with inhaled ipratropium bromide and 
inhaled placebo in patients with COPD. DE- 
SIGN: A stratified, randomized, double-blind, 
double-dummy, placebo-controlled, parallel 
group clinical trial. SETTING: Multiple sites at 
clinics and university medical centers through- 


Respiratory Care • July 1999 Vol 43 No 7 

Now Earn 

out the United States. PATIENTS: Four hun- 
dred eleven symptomatic patients with COPD 
with FEV| s 65% predicted and no clinically 
significant concurrent disease. Interventions; 
Comparison of inhaled salmeterol (42 microg 
twice daily), inhaled ipratropium bromide (36 
microg four times a day), and inhaled placebo 
(2 puffs four times a day) over 12 weeks. RE- 
SULTS: Salmeterol xinafoate was significantly 
(p < 0.0001) better than placebo and ipratro- 
pium in improving lung function at the recom- 
mended doses over the 12-week trial. Both sal- 
meterol and ipratropium reduced dyspnea 
related to activities of daily living compared 
with placebo; this improvement was associated 
with reduced use of supplemental albuterol. 
Analyses of time to first COPD exacerbation 
revealed salmeterol to be superior to placebo 
and ipratropium (p < 0.05). Adverse effects 
were similar among the three treatments. CON- 
CLUSIONS; These collective data support the 
use of salmeterol as first-line bronchodilator 
therapy for the long-term treatment of airflow 
obstruction in patients with COPD. 

The Combination of Ipratropium and Albu- 
terol Optimizes Pulmonary Function Revers- 
ibility Testing in Patients with COPD— Dor- 

insky PM. Reisner C, Ferguson GT, Menjoge 
SS, Serby CW, Witek TJ Jr. Chest 1999 Apr; 

STUDY OBJECTIVES: To determine whether 
the combination of ipratropium bromide and 
albuterol results in greater and more consistent 
pulmonary function test (PFT) response rates 
than ipratropium bromide or albuterol alone in 
patients with COPD. DESIGN: Retrospective 
review of two recently completed 3-month, ran- 
domized, double-blind, parallel, multicenter. 
phase III trials. SETTING: Outpatient. PA- 
TIENTS: A total of 1 ,067 stable patients with 
COPD. INTERVENTIONS: Ipratropium bro- 
mide (36 microg qid), albuterol base (180 mi- 
crog qid), or an equivalent combination of ipra- 
tropium bromide and albuterol sulfate (42 
microg and 240 microg qid, respectively). MEA- 
rates were analyzed using 12% and 15% in- 
creases in FEV| compared with baseline values 
and were measured in the various treatment 
groups on days 1, 29, 57, and 85 in these trials. 
Regardless of whether a 1 2% or a 1 5% increase 
in FEV| was used to define a positive response, 
an equivalent combination of ipratropium bro- 
mide and albuterol sulfate was superior to the 
individual agents (p < 0.05; all comparisons 
within 30 min). In addition, a 15% or more 
increase in FEV, was seen in > 80% of pa- 
tients who received the combination of ipratro- 
pium and albuterol sulfate during the initial PFT 
and continued to be observed 3 months after 
initial testing. CONCLUSIONS: Use of a com- 
bination of ipratropium bromide and albuterol 
sulfate is superior to the individual agents in 



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identifying PFT reversibility in patients with 

A Comparative Analysis of Arranging In- 
Flight Oxygen Aboard Commercial Air Car- 
riers — Stoller JK, Hoisington E, AugerG. Chest 
1999 Apr;ll5(4):991-995. 

INTRODUCTION: As air travel has become 
more commonplace in today's society, so too 
has air travel by oxygen-using individuals. Be- 
cause there is little oversight or standardization 
of in-fiight oxygen by the Federal Aviation Ad- 
mini.stration, individual airlines' policies and 
practices may vary greatly. On the premise that 
such variation may cause confusion by prospec- 
tive air travelers, we undertook the current study 
to describe individual air carriers' policies and 
practices and to provide guidance to future air 
travelers. METHODS; Data were collected by 
a series of telephone calls placed by the study 
investigators to all commercial air carriers listed 
in the 1997 Cleveland Metropolitan Yellow 
Pages. The callers were registered respiratory 
therapists who identified themselves as inexpe- 
rienced oxygen-requiring travelers wishing to 
arrange in-flight oxygen for an upcoming trip. 
Standard questions were asked of each carrier 
that included the following: Did the carrier have 
a special "help desk" to with oxygen ar- 
rangements? What oxygen systems, liter flow 

options, and interface devices were available? 
What was the charge for oxygen? How was the 
charge determined? What documentation from 
the physician was required? How much notifi- 
cation was required by the airline before the 
actual night? In addition to recording these re- 
sponses, the total amount of time spent on the 
telephone by the caller was logged along with 
the number of telephone calls and number of 
people spoken to in arranging in-flight oxygen. 
To compare oxygen charges between airlines, 
we calculated charges based on a "standard trip," 
which was defined as a nonstop, round-trip last- 
ing 6 h in which the traveler used a flow rate of 
2 L/min. RESULTS: Of the 33 commercial air 
carriers listed in the directory, 1 1 were US- 
based carriers and 22 were international-based 
carriers. Seventy-six percent of the airlines of- 
fered in-flight oxygen. For the 25 carriers of- 
fering in-flight oxygen, mean phone time re- 
quired to make the arrangements was 9.96±4.8 
min (range, 3 to 20 min). No more than two 
telephone calls were required to make oxygen 
arrangements. Most carriers required 48- to 72-h 
advance notice, with a single carrier requiring 
1 -month advance notice. Most carriers required 
some notification of oxygen needs by the trav- 
eler's physician. There was a great variation in 
oxygen device and liter flow availability. Liter 
flow options ranged from only two flow rates 
(36% of carriers) to a range of 1 to 15 L/min 

Respiratory Care • July 1999 Vol 43 No 7 



(one carrier). All carriers offered nasal cannula, 
which was the only device available for 21 car- 
riers (84%). Actual charges for in-flight oxygen 
also varied greatly. Six carriers supplied oxy- 
gen free and 18 carriers charged a fee (range, 
$64 to $1,500). One airline allowed the traveler 
to bring one "E" cylinder with no fee assessed. 
For 14 of the 18 carriers that charged, the charge 
for the standard trip ranged from $1(X) to $250. 
CONCLUSIONS: ( 1 ) As expected from the lack 
of standard regulations, the availability, costs, 
and ease of implementing in-flight oxygen vary 
greatly among commercial air carriers. (2) Be- 
cause the expense of in-flight oxygen is usually 
borne by the traveler (rather than by insurers), 
prospective travelers should consider charges 
for oxygen use when choosing an airline. (3) In 
the context that the current study shows sub- 
stantial variation in oxygen policies, costs, and 
services among commercial air carriers and that 
such policies may change over time, our find- 
ings encourage the prospective air traveler need- 
ing in-flight oxygen to "shop around." 

Immediate and Long-Term Results of Bron- 
chial Artery Embolization for Life-Threat- 
ening Hemoptysis — Mai H, Rullon I, Mellot 
F, Brugiere O, Sleiman C, Menu Y, Fournier 
M. Chest 1999 Apr;115(4):996-1001. 

STUDY OBJECTIVES: Bronchial artery em- 
bolization (BAE) has been established as an 
effective technique in the emergency treatment 
of life-threatening hemoptysis, but few data con- 
cerning long-term results and complications of 
the procedure are available. The aim of this 
study was to analyze retrospectively the expe- 
rience of BAE in our center with particular em- 
phasis on medium-term and long-term results 
and on morbidity. SETTING: University hos- 
pital. PATIENTS: Fifty-six patients underwent 
bronchial arteriography from 1986 to 1996 in 
our center for the management of life-threaten- 
ing hemoptysis. Of them, BAE was performed 
in 46 patients. Their mean age was 51 years 
(range, 19 to 89 years). The most frequent eti- 
ologies of hemoptysis were active or inactive 
tuberculosis, bronchiectasis, or idiopathic he- 
moptysis. RESULTS: BAE resulted in an im- 
mediate cessation of hemoptysis in 43 of the 
initial 56 patients (77%). During the first month 
after BAE, four patients who died from causes 
other than hemoptysis or who were referred to 
surgery were excluded from follow-up and in 
the 39 remaining patients, a complete cessation 
of hemoptysis was observed in 32 patients. A 
remission was noted in 28 of the 29 patients 
followed up between 30 and 90 days after BAE. 
Long-term control of bleeding was achieved in 
25 of the initial 56 patients (45%) followed up 
beyond 3 months after BAE (median follow-up 
of 1 3 months; range, 3 to 76 months). Overall, 
complications of BAE consisted of two epi- 

sodes of mediastinal hematoma and three epi- 
sodes of neurologic damage, two of which 
improved without permanent sequelae. CON- 
CLUSION: We conclude that BAE may result 
in long-term as well as immediate control of 
life-threatening hemoptysis but that complica- 
tions are not unusual. See the related editorial: 
Bronchial Artery Embolotherapy for Control 
of Acute Hemoptysis: Analysis of Outcome. 
White RI Jr. Chest 1999 Apr:115(4):9I2-9l5. 

Late Outcome from Percutaneous Tracheos- 
tomy Using the Portex Kit — Leonard RC, 
Lewis RH, Singh B, van Heerden PV. Chest 
1999 Apr;I15(4):1070-1075. 

OBJECTIVE: To assess late outcome follow- 
ing percutaneous tracheostomy using the Por- 
tex kit (Hythe, Kent, UK). DESIGN: Prospec- 
tive observational cohort study. SETTING: 
Teaching hospital. PATIENTS: Forty-nine con- 
secutive patients who underwent percutaneous 
tracheostomy in the ICU using the Portex kit 
and who survived 6 months after the procedure. 
INTERVENTIONS: Questionnaires regarding 
six symptoms were sent to all 49 surviving pa- 
tients; the 39 respondents were invited to attend 
for review. Thirteen patients underwent pulmo- 
nary function testing, of whom 1 also under- 
went fiberoptic laryngotracheoscopy under lo- 
cal anesthesia. RESULTS: The most common 
symptom was a minor change in voice. One 
patient had required treatment for symptomatic 
tracheal stenosis by the time of review; one was 
referred for revision of a tethered scar. Pulmo- 
nary function testing was easily performed by 
all patients and revealed no evidence of upper 
airway obstruction. Tracheoscopy likewise 
showed no evidence of tracheal stenosis. CON- 
CLUSIONS: One of 49 patients had developed 
tracheal stenosis. None of the patients attending 
for detailed review showed any sign of late com- 
plications other than one tethered scar. 

The Incidence of and Clinical Variables As- 
sociated with Vancomycin-Resistant Entero- 
coccal Colonization in Mechanically Venti- 
lated Patients — Bhorade SM, Christenson J, 
Pohlman AS, Arnow PM, Hall JB. Chest 1999 

STUDY OBJECTIVES: (1) To determine in 
our ICU the incidence of vancomycin-resistant 
enterococcus (VRE) colonization in mechani- 
cally ventilated patients without a history of 
VRE infection or colonization; and (2) to de- 
termine the risk factors and outcome variables 
associated with VRE colonization in these pa- 
tients. DESIGN: A prospective cohort study con- 
ducted between January 1996 and March 1998. 
SETTING: Medical and cardiac critical care 
units in a tertiary care urban university hospital. 
PATIENTS: Mechanically ventilated patients 

without evidence of pneumonia at the onset of 
ventilation. INTERVENTIONS: None. MEA- 
derwent rectal cultures by standard methods on 
day 1, day 3 or 4, day 6 or 7, and day 14 of 
intubation to detect VRE. Thirteen of 83 pa- 
tients ( 1 6%) had rectal cultures positive for VRE 
(VRE+) at some point while being mechani- 
cally ventilated during their stay in the ICU. In 
comparison, approximately 15 of 2,100 medi- 
cal ICU patients (0.7%) had clinical VRE in- 
fections as determined by the hospital's infec- 
tion control program during a 2-year period. 
VRE-t- patients had a higher incidence of im- 
munosuppression than padents who had rectal 
cultures negative for VRE (VRE-) (9 of 1 3 [69%] 
vs 16 of 70 [23%], respectively; p < 0.01) and 
neutropenia (4 of 13 [31%] vs 5 of 70 [7%], 
respectively; p < 0.01). Hospital length of stay 
(LOS) was longer in VRE-)- patients than in 
VRE- patients (27±17 days vs 17±14 days, 
respectively; p = 0.05), whereas pre-ICU hos- 
pital LOS and ICU LOS were similar in both 
patient groups. Five of 67 patients (7%) were 
VRE -I- on day 1 of intubation, suggesting col- 
onization at a prior site of care. Three of 29 
patients who had subsequent rectal cultures con- 
verted to VRE -I- while in the ICU. This group 
had a higher incidence of immunosuppression 
and neutropenia, and received more vancomy- 
cin compared with the patients who remained 
VRE- (p < 0.01). However, there was no sig- 
nificant difference in the use of other broad- 
spectrum antibiotics (such as antipseudomonal 
penicillins, third-generation cephalosporins, 
quinolones, and clindamycin), enteral tube feed- 
ings, or sucralfate between the two groups. In 
addition, a topical antibiotic paste (a gentami- 
cin, nystatin, polymixin slurry) that was placed 
in the oropharynx to prevent bacterial over- 
growth was not found to increase the incidence 
of VRE colonization in this patient population. 
CONCLUSIONS: The incidence of VRE colo- 
nization was surprisingly high: 16% in mechan- 
ically ventilated patients in a hospital in which 
VRE was not previously known to be endemic. 
Risk factors for the acquisition of VRE coloni- 
zation included immunosuppression, neutrope- 
nia, and vancomycin use. Increased LOSs and 
hospital costs were seen in VRE -I- patients com- 
pared to VRE- patients. Whether VRE coloni- 
zation is a contributor to severe disease that 
leads to prolonged hospitalization and increased 
resource allocation or whether it is simply a 
marker of disease severity cannot be determined 
from this study. To the extent that specific an- 
tibiotic protocols are used to reduce antibiotic- 
resistant flora in the ICU, monitoring the inci- 
dence of VRE in the stool specimens of 
immunocompromised, mechanically ventilated 
patients can be a simple and u.seful tool to as- 
sess one effect of these strategies. 


Respiratory Care • July 1999 Vol 43 No 7 

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Requires Windows 3.1 or higher • Available on 31/2" disk • PC Format only 

Hhest Trauma Simulation 

imulates a 62-year-old man involved in a motor vehicle 
ccident. The user must perform initial assessment and 
ecommend initial therapy to stabilize the patient. In the course 
f the treatment, the patient undergoes surgery for a thoraco- 
smy and is then placed on a mechanical ventilator. The user is 
sked to recommend initial ventilator settings. Subsequent 
ecision-making sections include recommending fiberoptic 
ronchoscopy, making further ventilator changes based on 
lBG values, and evaluating the patient for possible extubation. 
tem SPIO 

Status Asthmaticus Simulation 

nvolves the initial assessment of a 35-year-old man with a 
istory of allergic asthma. Low-flow oxygen is administered 
litially, followed by bronchodilator therapy. As the simulation 
rogresses, the patient is intubated and receives mechanical 
entilation. The user is required to make initial settings and 
djustments according to ABG results and patient response. 
lIso included in the simulation is a switch to IMV mode, 
edation, and eventual extubation and placement on a 40 per 
ent aerosol mask. 
tem SP12 

Acute Respiratory Distress Syndrome 
(ARDS) Simulation 

This simulation presents a 30-year-old man 36 hours after 
emergency surgery for excision of a large duodenal ulcer; the 
patient is now restless and complaining of dyspnea. The 
simulation proceeds through initial oxygen therapy, followed 
by increasing F[o,, and then CPAP. The patient is eventually 
intubated and placed on a mechanical ventilator, where 
deteriorating ABGs and static compliance call for increasing 
PEEP, which is gradually increased to 25 cmwp. ABGs, 
compliance, and shunt studies are used to evaluate the 
effectiveness of the PEEP therapy. 
Item SP15 

Epiglottitis Simulation 

Presents a 4-year-old girl entering the ER with a "cold" and 
elevated temperature. A lateral neck x-ray reveals massive 
edema of the epiglottis, whereupon the child is taken to surgery 
and intubated. The user is asked to recommend appropriate 
airway and size for the patient. After further assessment, CPAP 
is initiated with room air, and two days later the patient is 
evaluated for extubation and postextubation therapy. 
Item SP16 


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Hhest Tubes and Pleural Drainage 

lelps you understand the purpose of pleural drainage, 
low it might affect the patient's respiratory status, and what 
irecautions you must take when working with patients 
/ho are receiving pleural drainage, 
tem CP3 

fracheal Intubation I: 
Jpper Airway Anatomy 
ind Goals of Intubation 

Vfter completing this IISP, you will 
inderstand the rationale for tracheal 
ntubation and be able to identify the 
mportant landmarks of upper airway 
tem CP4 

Equipment Procedures for Intubation 

Identifies all equipment required to perform either oral or nasal 
tracheal intubation, while explaining necessary steps before and 
after intubation. Discusses common errors and differences in 
procedures for infants and pediatric patients. 
Item CP6 

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Tracheal Intubation II: 
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Describes the four routes of tracheal 

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Part ir of II Special Issues 

Presented by the Editorial Board of the 

Respiratory Care journal 

Containing the manuscripts and discussions from the Journal 
Conference held December 4-6, 1998, Cancun, Mexico 

Supported by the American Association for Respiratory Care 

Conference faculty members — front row, from left: Michael ] Bishop MD, Maxine Orringer MA CCC-SLP. Charles G Durbin 
]r MD, Charles B Watson MD, Richard D Branson RRT, William E Hurford MD. Second row, from left: John L StaufPer MD, 
Ann E Thompson MD, James K Stoiler MD. Ray Ritz RRT. James F Reibel MD, John E Heffner MD, Robert S Campbell RRT, 
Dean R Hess PhD RRT FAARC. ::^^!^^^^sm^mmimsmemmmsimKmmiiimmmimmmmiBmimssmi^^mmHmm 


Richard D Branson RRT — Cincinnati, Oiiio 
and Ciiarles G Durbin Jr MD — Charlottesville, Virginia 


Michael ) Bishop MD 
Seattle, Washington 

Richard D Branson RRT 

Robert S Cambeii RRT 
Cincinnati, Ohio 

Charles G Durbin jr MD 

Charlottesville, Virginia 

John E Heffner MD 
Charleston, South Carolina 

Dean R Hess PhD RRT FAARC 

Boston, Massachusetts 

William E Hurford MD 
Boston, Massachusetts 

Maxine Orringer MA CCC-SLP 

Pittsburgh, Pennsylvania 

James F Reibel MD 

Charlottesville, Virginia 

Ray Ritz RRT 

Boston, Massachusetts 

John L Stauffer MD 
Hershey, Pennsylvania 

James K Stoiler MD 
Cleveland, Ohio 

Ann E Thompson MD 
Pittsburgh, Pennsylvania 

Charles B Watson MD 
Bridgeport, Connecticut 

Conference Proceedings 

Who Should Perform Intubation? 

Michael J Bishop MD 


Legal Issues 

Practice Guidelines 

Intubation Training and Studies of Intubation Performance 

A Two-Tiered Approacli to Airway Management 


[Respir Care 1999;44(7):750-755] Key words: intratracheal intubation, airway 

obstruction, cardiopulmonary resuscitation, practice guidelines. 


Clearing and maintaining a patent airway is first and 
foremost during resuscitation. "Airway" is the "A" in the 
ABC's of resuscitation. Perhaps because of the importance 
of opening the airway, it is a skill that often becomes an 
area of controversy and "turf wars." Failure to manage the 
airway adequately tends to lead to criticism, recrimina- 
tions, and a significant number of medical malpractice 
actions.' Such failures are especially likely to occur during 
intubations outside of the operating room (OR), where 
conditions are not as controlled, patients are more likely to 
be on the floor or on soft beds, vomitus may be present, 
and other conditions may be sub-optimal.^-^ This article 
explores the questions of what personnel are qualified to 
manage the airway during in-hospital resuscitations, and 
what training they should have. 

Since precedents seem clearly established for paramed- 
ical personnel to perform outside-of-hospital intubation, 
the present discussion considers resuscitations and endo- 
tracheal intubations that occur in the hospital but outside 
of the OR. In-hospital OR intubations are generally carried 
out by the anesthesia staff, who have been extensively 
trained in airway management. Thus, the outside-of-OR 
patient seems to be the subject of greatest controversy. 

Michael J Bishop MD is affiliated with the Department of Anesthesiol- 
ogy, Veterans Administration Puget Sound Health Care System, and with 
the University of Washington School of Medicine, Seattle, Washington. 

Correspondence: Michael J Bishop MD, Department of Anesthesiology, 
Puget Sound Veterans Affairs Health Care System, 1I2A, 1660 South 
Columbian Way, Seattle WA 98108. E-mail: bish@u. 

Decisions about who performs intubation need to be 
site-specific. Within the academic medical center, there 
may be many groups vying to perform intubation in order 
to satisfy training requirements (Table 1 ). Conversely, small 
community hospitals may have a dearth of individuals 
interested in undergoing the required training. 

Numerous articles exist concerning the question of who 
should perform endotracheal intubation." Most of these 
articles assess the likelihood of the tube ending up in the 
trachea, with various comparisons made as to whether the 
letters after the intubator's name are MD, RRT, or EMT. 
This review summarizes the existing literature and legal 
issues, and proposes a two-tiered system in which respi- 
ratory therapists are allowed to perform endotracheal in- 

Legal Issues 

Regulatory and legal literature provide relatively little 
guidance in determining who should manage the airway, 
and there are no legal precedents as to who should manage 
the airway or who should perform endotracheal intubation. 
A search of a legal database (Westlaw, West Publishing 
Co, Eagan, Minnesota) revealed no appellate decisions 
bearing directly on this question. However, what is clear is 
that nonphysician personnel who undertake medical ser- 
vices are subject to the same standards of performance as 
the physicians who would usually perform the same ser- 
vice (Belmon v St Frances Cabrini Hospital, All So 2d 
541 [1983]). 

The only legal decision relating to a failed intubation 
was in the case of a patient who arrested; the respiratory 
therapist was unable to intubate the patient, and the patient 


Respiratory Care • July 1999 Vol 44 No 7 

Who Should Perform Intubation? 

Table 1 . Groups Vying for Intubation Experience 

Respiratory therapy students 

Respiratory therapists (pediatric and neonatal transport teams) 

Respiratory therapists (resuscitation team) 

Student nurse anesthetists 

Flight team personnel 

Critical care fellows 

Resident physicians 



Thoracic diseases — pulmonary medicine 

Medical students 

Table 2. Required Skills for Intubation Certification 

From Reference 4. 

was intubated by a physician. The hospital was found 
Hable for the original failed intubation, but the basis of the 
liability was the lack of immediate availability of a Macin- 
tosh #4 laryngoscopy blade for the respiratory therapist, 
not the personnel involved {Dickson v Taylor, 431 SE 2d 
778 [1993]). 

Medico-legal cases often revolve around the "standard 
of care." The standard of care is not a written code but is 
defined on an ad hoc basis by a judge or jury during the 
case.^ The standard may vary from region to region, state 
to state, or even within states. In terms of "standard-of- 
care," the standard might vary between a major tertiary 
urban trauma center and a rehabilitation hospital. It would 
be a reasonable assumption that the former would be pre- 
pared to handle the complexities of the airway in a patient 
with major head and neck trauma requiring possible sur- 
gical intervention, whereas for the latter, the standard of 
care might be basic life support until community paramed- 
ics arrive. 



Access airway for difficult 

Describe views of larynx 
Understand indications 

and contraindications 

of muscle relaxants 
Plan for failed intubation 
Identification of successful 


1) Using bulb syringe 

2) Using end-tidal CO2 

Bag and mask ventilation 
Application of cricoid pressure 
Intubation using Macintosh and Miller 

Intubation over a gum elastic bougie 
Placement of a laryngeal mask airway 

ation,' and the American Association for Respiratory Care 
Clinical Practice Guideline for Resuscitation in Acute Care 
Hospitals.* Both of these sources address the training of 
individuals involved in airway management during resus- 

Who should manage the airway during in-hospital re- 
suscitation? In teaching hospitals, it often seems that ev- 
eryone wants to get in on the act. In community hospitals, 
there may be no anesthesiologist on duty during off-hours, 
or the anesthesiologists may all be occupied in the oper- 
ating room.' The key questions then are (1) Who is avail- 
able to manage the airway? (2) Who has the educational 
background to do so? and (3) Who has the skills to do so? 

While no specific guidelines are available, the Advanced 
Cardiac Life Support manual notes "As soon as practical 
during the resuscitative effort, the trachea should be intu- 
bated by trained personnel . . . who either perform intuba- 
tions frequently or are retrained frequently."^ 

Intubation Training and 
Studies of Intubation Performance 

Practice Guidelines 

There are no absolute standards determining who should 
intubate, but some guidelines do exist. Practice guidelines 
are created to assist practitioners and institutions in mak- 
ing appropriate decisions and to provide them with input 
regarding presumed optimal practice. They are generally 
created by a group of experts whose combined experience 
exceeds that of any of the individuals involved in their 
development. Guidelines are not standards,^'' and follow- 
ing a guideline or a standard obviously can never guaran- 
tee a desirable outcome. Also, guidelines differ from writ- 
ten standards in that they permit a practitioner or an 
institution to exercise judgment within reasonable limits. 

Existing guidelines relevant to airway management dur- 
ing resuscitation include the Advanced Cardiac Life Sup- 
port guidelines published by the American Heart Associ- 

Endotracheal intubation is within the respiratory thera- 
pist's scope of practice, but intubation by therapists is 
dependent on local and regional practice. Almost all reg- 
istry-level respiratory therapy programs instruct students 
in the technique, and 300 of 400 accredited respiratory 
care education programs teach intubation. 'o Certainly all 
therapists are routinely trained in evaluation of tube place- 
ment, tube manipulation, and measurements of cuff pres- 
sures and volumes. The exam content outline for registry 
status from the National Board for Respiratory Care in- 
cludes endotracheal intubation as part of the exam con- 
tent.* Table 2 lists the cognitive and procedural skills we 
feel are critical in order to competently perform emer- 

National Board for Respiratory Care Registry Examination content 
outline. National Board for Respiratory Care, Lenexa, Kansas. 

Respiratory Care • July 1999 Vol 44 No 7 


Who Should Perform Intubation? 

gency endotracheal intubation. At our institution we place 
great emphasis on instructing therapists in backup plans in 
case initial intubation attempts are unsuccessful. 

A survey of non-OR emergency airway management 
reported that in 1 34 hospitals with anesthesiology residen- 
cies, respiratory therapists were responsible for floor in- 
tubations in only one of the hospitals." However, these 
hospitals were all greater than 200 beds, and the majority 
were more than 500 beds. Thus, they were likely to have 
routinely available full-time in-hospital physicians with 
airway training. Furthermore, the vast majority of hospi- 
tals do not have anesthesiology training programs. The 
number of anesthesiology training programs in the United 
States has declined in each of the last 3 years and as of 
July 1 999 has declined to approximately 1 40, representing 
only a small minority of hospitals in the country.* Many of 
the existing programs have cut back on the number of 
residents being trained, limiting staffing. 

The frequency of failed intubation in the anesthesia lit- 
erature is generally well under 1%.'2-|4 Of course, these 
are under well controlled conditions in the OR and may 
not apply outside of the OR. Given that the rate of failed 
intubations is low, any study to demonstrate a difference 
among personnel in intubation skills would, in order to be 
valid, require enormous numbers of patients. Consider the 
following statistical example: If anesthesiologists had a 
true failed intubation rate of 2%, and we assumed a para- 
medic group to have a true failure rate double that, a 
patient population of approximately 1 ,000 patients would 
need to be studied before this 100% difference in failure 
rate became statistically significant at the p < 0.05 level ! 
Thus, the most likely conclusion of such studies will be 
that there is no difference, but such studies are often flawed 
by insufficient numbers of patients. 

One of the most widely cited papers supporting the use 
of nonanesthesiologists found that there was no difference 
in complication rates during emergency room intubation 
whether the procedure was performed by anesthesiology 
staff or by emergency department staff. '^ Reanalysis of 
these data reveals several critical flaws. Staff included as 
anesthesiology staff included obstetric and surgery resi- 
dents who were rotating through the service and thus had 
little specialized training. In addition, all levels of anes- 
thesiology training were included. Therefore, complica- 
tions may have resulted from attempts by junior residents 
with no real specialized training. The study found that 14 
of 23 patients intubated by emergency department staff 
died, and 1 2 of 20 intubated by anesthesiology staff died 
(no significant difference). This seems a poor indicator of 
who holds greater competence. A second piece of evi- 

* Information from the American Association of Anesthesia Program 
Directors, Parle Ridge, lUinois. 

dence offered by these authors is that there were compli- 
cations in 20 of 23 patients intubated by the emergency 
department, and in 14 of 23 intubated by the anesthesiol- 
ogy staff. Again, they note no significant difference by 
chi-square analysis. If the more appropriate Fisher's exact 
test is used, we find p < 0.05. Given that the complication 
rate was nearly 43% higher in the emergency department 
group, these data could be reinterpreted as supporting the 
routine use of anesthesiologists! That this has become one 
of the most widely cited papers on the topic is unfortunate, 
and demonstrates the difficulties in citing studies when 
"turf wars" arise. 

Most physicians receive little training in airway man- 
agement, so the alternative provider to an anesthesiologist 
should be someone specifically trained in these skills, rather 
than a physician without airway management training. Cer- 
tified registered nurse anesthetists routinely perform en- 
dotracheal intubation. Since the 1970s, paramedics in some 
regions have been trained in intubation. In 1977, DeLeo"' 
reported a 91% success rate by paramedical personnel in a 
field intubation, versus 89% for physicians. Paramedic suc- 
cess rates in other studies have generally ranged from 90 
to 98%." One study found that unsuccessful intubations 
by field personnel were generally in patients who could 
not be intubated by emergency room physicians.'** 

What data do we have concerning respiratory thera- 
pists? In 1981, McLaughlin and Scott reported that 50 
consecutive patients were intubated on an emergency basis 
by respiratory therapists.'* The therapists each had per- 
formed 12 operating room intubations and 2 supervised 
emergency intubations prior to the start of the study. Ten 
percent of these cases required more than 5 minutes for 
intubation. This seems surprisingly high. Twenty-five dif- 
ferent therapists were involved, raising the possibility that 
even though the initial training was adequate, there may 
have been insufficient opportunity for reinforcement of the 

Another 1981 study in a community hospital found a 
complication rate of 18% when respiratory therapy per- 
sonnel performed intubations and 57% when a physician 
attempted the intubation. ** When the data are examined 
more closely, it becomes clear that the high physician 
complication rate was due to a greater than 50% initial 
esophageal placement by nonanesthesiologist physicians. 
Therapists had a 10% initial esophageal placement. No 
data are given as to whether this was recognized in all 
cases. In any case, this study again supports the success of 
nonphysician providers when compared with nonanesthe- 
siology physicians. 

Thalman et al report^" that at Duke University Medical 
Center, where respiratory therapists have performed intu- 
bation for many years, the therapists were successful in 
791 of 833 intubations (95%) with anesthesiologists avail- 
able for backup as needed. A key feature of this service 


Respiratory Care • July 1999 Vol 44 No 7 

Who Should Perform Intubation? 

Table 3. Reported Results for Intubations Conducted Outside of the Operating Room 




Experience {% failure) 

Mascia & Matjasko'' 
McLaughlin & Scott'' 
Conley & Smith'' 





Certified nurse anesthetists 

Other physicians 

Critical care physicians 



House physicians or anesthesiologists 


In-hospital 13/613 failed (2) 

In-hospital 50/50 intubated, but 10% required longer than 5 minutes 

In-hospital 3/74 failed (4) 

0/30 failed 

0/5 failed 

4/34 failed (12) 

0/297, 13 required > 4 attempts, 2 required 10 attempts 

42/833 (5) 

18/178 (10) 

1/97 failed (1) 

20% required > 4 attempts 

70/779 (8) 

74/785 failed (9) 

Schwartz et al"" 
Thalman et al"" 
Zyla & Carson^' 
Stauffer et al^' 

Stewart et aP" 

From Hussey JD, Bishop MJ, Massey L. Lakshniinarayan S. Joy J. Finley J. Two-tiered response for emergency airway managemenl by respiratory therapists and anesthesiologists. Respir Care 1998: 


Intensive care unit 

Field cardiac arrest 

was a core group of therapists designated for airway sup- 
port. In a large institution, having a highly trained sub- 
group of therapists may be a useful strategy. 

The Respiratory Care Department at Butterworth Hos- 
pital, Grand Rapids, Michigan, published their experience 
as back-up providers of endotracheal intubation following 
failed attempts by nonanesthesiologist physicians.-' Their 
success rate of 90% is remarkable given that these were 
cases in which a physician had already failed. In the case 
where the therapist failed, most patients were eventually 
intubated by an anesthesiologist or required a tracheos- 
tomy. The providers in this study all performed 12-15 
successful OR intubations and kept up their skills by per- 
forming a minimum of 15 intubations every 2 years. 

Table 3 summarizes the data from 9 studies of outside- 
of-OR intubations. Clearly, the vast majority of intuba- 
tions can be performed successfully by therapists. What is 
an acceptable rate for failure? Ten percent would obvi- 
ously be far too high if all patients died as a result of the 
failed intubation. However, when an esophageal intuba- 
tion is recognized, consequences can usually be minimized 
by returning to mask ventilation. In rare cases, surgical 
access to the airway may be required. With the advent 
during the last 10 years of reliable devices for detecting 
esophageal intubation, unrecognized misplacement should 
virtually disappear, and the reported rates of initial intu- 
bation failure seem less and less worrisome. 
* Whether respiratory therapists should be providers of 
intubation services on a routine basis should probably de- 
pend on the level of other personnel available. It would 
seem reasonable to use the most skilled practitioners in the 
hospital. Few would disagree that anesthesiologists, accus- 
tomed to performing several intubations a day, have the 
highest skill level. However, cost considerations, as well 

as their preoccupation in the operating room, may prevent 
having an anesthesiologist routinely available. Under those 
circumstances, the practitioner with the next greatest ex- 
perience and familiarity with intubation and airway main- 
tenance should probably be designated. With appropriate 
training and skill maintenance, this will often be the re- 
spiratory therapist. Furthermore, respiratory therapists have 
the ability to manage the airway should intubation fail, 
since they have substantially more experience in bag-and- 
mask ventilation than most physicians. 

A Two-Tiered Approach to Airway Management 

At the Puget Sound Veterans Affairs Health Care Sys- 
tem we recently implemented a two-tiered response sys- 
tem for emergency airway management. This system was 
developed based on the experience that the most complex 
intubations tended to be urgent rather than emergency. 
Cardiac arrest cases rarely require pharmacologic inter- 
vention to produce muscle relaxation or sedation, whereas 
unstable but not arrested patients are at high risk of dete- 
rioration. A study of emergency room intubations found 
that 9 of 22 nonarrested patients required prolonged at- 
tempts at intubation versus only 3 of 2 1 patients who had 
suffered cardiac arrest,-' supporting the concept that the 
nonarrest patients were more complex. 

Our model was designed to have respiratory therapists 
intubate the trachea of patients suffering cardiac arrest, 
with the anesthesiologist available for backup consulta- 
tion. When the anesthesiologist was not in-hospital, the 
consultations took place by telephone as needed. Patients 
requiring intubation for respiratory failure, airway main- 
tenance, or other progressive conditions were considered 
more complex situations, and an anesthesiologist was rou- 

Respiratory Care • July 1999 Vol 44 No 7 


Who Should Perform Intubation? 

Need for tracheal 
intubation identified 

Emergency (< 30 minute 
response needed) 



In house 



Out of house 
anesthesiologist notified 




performs airway 
management or 
supervises respiratory 

Respiratory therapist 
manages airway and 
provides consultation by 
mobile phone. 

Urgent (30 minute 
delay acceptable) 

Anesthesiologist notified 
and proceeds to hospital 



Patient remains 
stable until 

Fig. 1 . Algorithm for two-tiered response system for emergency airway management. This was the basic model for the procedure to be 
followed when the need was identified for tracheal intubation outside of the operating room. (Modified From Hussey JD, Bishop MJ, Massey 
L, Lakshminarayan S, Joy J, Finley J. Two-tiered response for emergency airway management by respiratory therapists and anesthesiol- 
ogists. Respir Care 1 998;43[7]552-556.) 

164 Out-of-operating 
room intubations 

89 Cardiac arrests 


75 Non-code cases 

39 - Anesthesiologist 
present (all intubated) 

50 - No anesthesiologist 


65 - Anesthesiologist 
present (all intubated) 

10 Emergency (no 
(all intubated) 

48 Successful intubations 

Fig. 2. Results of the 164 consecutive intubations performed outside of the operating room during the first 18 months of implementation 
of the model shown in Fig. 1. (Modified From Hussey JD, Bishop MJ, Massey L, Lakshminarayan S, Joy J, Finley J. Two-tiered response 
for emergency airway management by respiratory therapists and anesthesiologists. Respir Care 1998;43[7]552-556.) 

tinely present for such cases. The complete algorithm for 
this model is shown in Figure 1 . The results of the first 1 8 
months of using this model are shown in Figure 2. Of 164 
patients, 162 were successfully intubated, which compares 
favorably with the published experience summarized in 
Table 3. 

The training required for respiratory therapists to intu- 
bate depends on the nature of the patients to be intubated 
and the availability of physician support. Training in the 
pharmacology of sedative drugs, neuromuscular blocking 
drugs, and drugs required for hemodynamic support would 

require extensive coursework, and administration of such 
drugs is not generally within the scope of practice of the 
respiratory therapist. Our two-tiered response system lim- 
its the need for such training, since a physician trained in 
intubation is always available, via cell telephone if not in 
person. Furthermore, a house medical officer is always 
present at all arrests and can provide assistance as needed. 
However, even in arrest and near-arrest situations, there 
still may arise a need for neuromuscular blockade to fa- 
cilitate intubation. Neuromuscular blocking drugs have 
been shown to increase the success rate of field intubations 


Respiratory Care • July 1999 Vol 44 No 7 

Who Should Perform Intubation? 

and may be critical for intubation success in the patient 
who has remaining muscle tone.-^ Consequently, training 
should be provided in understanding the onset of action of 
succinylcholine, as well as a nondepolarizing muscle re- 
laxant. In our institution, we have provided each therapist 
with a laminated card noting a suitable dose of succinyl- 
choline, or, for patients with a history of neurologic deficit 
or bum, the appropriate dose of a nondepolarizing relax- 
ant. This card can then be shown to the medical house 
officer to order the drug, even if they are not completely 
familiar with the dose. 

There is no set answer to deciding how much training is 
required before an individual is prepared to intubate pa- 
tients independently. One report used 12 intubations as a 
minimum for therapist certification.''* In our institution, 
the supervising anesthesiologist must provide final certi- 
fication that all skills have been achieved. This requires a 
mean of 31 ± 17 (mean ± SD) attempts, with a range of 
15-46. This mean correlates well with a study of anesthe- 
siology trainees learning to perform intubation: the learn- 
ing curve is steep initially, with an 80% success rate after 
30 intubations, but then flattens out, with only gradually 
increasing success rates with further training.-'' 


The literature clearly suggests that respiratory therapists 
are generally well qualified to conduct endotracheal intu- 
bations. While the respiratory therapist certainly does not 
possess the knowledge of pharmacology and underlying 
conditions that a physician does, many respiratory thera- 
pists have more intubation experience than the some phy- 
sicians, and most respiratory therapists can provide rapid 
and efficient airway management with a high degree of 
safety. Anesthesiologists and certified registered nurse 
anesthetists have the most intubation experience, but are 
not always available, and respiratory therapists can per- 
form intubations at a lower cost. For this reason, we rec- 
ommend a two-tiered system in which the respiratory ther- 
apist is permitted to conduct intubations in the context of 
rapidly-available consultation from the anesthesiologist. 


1. Cheney FW, Posner KL. Caplan RA. Adverse respiratory events 
infrequently leading to malpractice suits, a closed claims analysis. 
Anesthesiology 1991 ;75(6):932-939. 

2. Mon TC, Tiernan JF. Airway related complications of emergency 
intubation (abstract). Chest 1993;104:48S. 

3. Mascia MF. Maljasko MJ. Emergency airway management by an- 
esthesiologists (abstract). Anesthesiology I993;79(3):A1054. 

4. Buck C, Southorn PA. Who should perfonn endotracheal intubation? 
A summary of i.ssues. (editorial) Respir Care I994;39(l):17-I8. 

5. Gin.sburg WH Jr. When does a guideline become a standard? The 
new American Society of Anesthesiologists guidelines give us a 
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6. Practice guidelines for management of the difficult airway. A report by 
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of the Difficult Airway. Anesthesiology 1993;78(3):597-602. 

7. Guidelines for cardiopulinonary resuscitation and emergency cardiac 
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JAMA 1992:268(16):2I99-2241. PiihUshecl ermiiim JAMA 1994: 

8. Clinical Practice Guidelines. Resu.scitation in acute care hospitals. 
Respir Care 1993;38(1 1):1 179-1 188. 

9. Conley JM. Smith DJ. Emergency endotracheal intubation by respi- 
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10. Kacmarek RM. The role of the respiratory therapist in emergency 
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1 1 . Nayyar P, Lisbon A. Non-operating room emergency airway man- 
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12. Benumof JL. Management of the difficult adult airway. With special 
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13. Samsoon GL, Young JR. Difficult tracheal intubation; a retrospec- 
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14. Lyons G. Failed intubation; six years' experience in a teaching ma- 
ternity unit. Anaesthesia 1985:4()(8);759-762. 

15. Taryle DA. Chandler JE. Good JT, Potts DE. Sahn SA. Emergency 
room intubations — complications and survival. Chest 1979:75(5); 

16. DeLeo BC. Endotracheal intubation by rescue squad personnel. Heart 
Lung l977;6(5);851-854. 

17. Pepe PE, Copass MK. Joyce TH. Prehospital endotracheal intuba- 
tion; rationale for training emergency medical personnel. Ann Emerg 
Med 1985:14(1 1);1085-1092. 

18. Jacobs LM. Berrizbeitia LD. Bennett B. Madigan C. Endotracheal 
intubation in the prehospital phase of emergency medical care. JAMA 

19. McLaughlin AJ Jr, Scott W. Training and evaluation of respiratory 
therapists in emergency intubation. Respir Care 198l:26(4);333- 

20. Thalman JJ. Rinaldo-Gallo S. Maclnlyre NR. Analysis of an endo- 
tracheal intubation service provided by respiratory care practitioners. 
Respir Care 1993;38(5);469^73. 

21. Zyla EL, Carson J. Respiratory care practitioners as secondary pro- 
viders of endotracheal intubation; one hospital's experience. Respir 
Care 1994:39(1 );.30-33. 

22. Schwartz DE. Matthay MA, Cohen NH. Death and other complica- 
tions of emergency airway management in critically ill adults; a 
prospective investigation of 297 tracheal intubations. Anesthesiol- 
ogy 1995:82(2);367-376. 

23. Stauffer JL, Olson DE, Petty TL. Complications and conse- 
quences of endotracheal intubation and tracheostomy; a prospective 
study of 150 critically ill adult patients. Am J Med 1981:7()(1);65- 

24. Stewart RD. Paris PM. Winter PM, Pelton GH. Cannon GM. Field 
endotracheal intubation by paramedical personnel, success rates and 
complications. Chest 1984:85(3);341-345. 

25. Murphy-Macabobby M, Marshall WJ. Schneider C. Dries D. Neu- 
romuscular blockade in aeromedical airway management. Ann Emerg 
Med l992:21(6);664-669. 

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skills in anesthesiology; is there a recommended number of cases 
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Respiratory Care • July 1999 Vol 44 No 7 


Who Should Perform Intubation? 


Hurford: That was a very nice pre- 
sentation of the situation at your hos- 
pital, and I imagine it parallels the sit- 
uation at hospitals where there is either 
no emergency department or a not- 
very-busy one, and where intubation 
is relatively infrequent, as it is in your 
institution. The frequency of intuba- 
tion events occurring when there is no 
anesthesiologist present is extremely 
low, it seemed, by your data, a rela- 
tively rare event — 1.5 per month or 
something like that. Obviously, other 
hospitals are different. Level 1 trauma 
centers have young, healthy, salvage- 
able people arrive at the emergency 
department in respiratory distress. Ev- 
erybody wants to play like the TV 
show ER. Those types of scenarios are 
much more dangerous to health care 
in general today, because you're los- 
ing a certain proportion of salvage- 
able patients. Pediatric ERs are an- 
other case in point. The types of 
patients in the hospital (difficult air- 
way patients, ear-nose-throat patients, 
for example), are also important. In 
our hospital, for example, we have sim- 
ilar difficulties where we are so large 
that we cannot supply anesthesiolo- 
gists to outlying facilities, neighbor- 
hood health care centers, or doctors' 
offices that are 3 blocks away when 
they want a code response team. We' ve 
had to work out a code response team 
to try to do that, but one of the options 
that has been described, and certainly 
occurs in rehab hospitals and chronic 
care hospitals, is to call 9 1 1 and have 
the paramedics come. 

Bishop: That's actually the response 
plan in our hospital for the outlying 
buildings. For instance, radiation on- 
cology is in an outlying building. We 
have a couple of other facilities that 
are in outlying buildings, and that's 
the plan. We had a code call in one of 
the outlying buildings on our campus, 
and not only were the paramedics there 
before anybody from the main hospi- 
tal, they also had the equipment to 

take care of things that occur in the 
field. We didn't have suction; they had 
a portable suction set up. They were 
used to doing things in the field, and I 
think that's absolutely right. 

Hurford: Is there a point in a hos- 
pital's activity level at which an emer- 
gency department physician or in- 
house anesthesiologist becomes cost- 
effective? Or is it never reasonable to 
have an additional person in-house to 
cover codes? 

Bishop: I think it depends on the 
particular way you've set things up. 
We've set it up so that the frequency 
of emergency intubations is pretty low. 
I think you just have to make the cal- 
culations. Look at the value added, 
and go through it for your individual 
situation. I think you brought the point 
up that, obviously, at, say, an outpa- 
tient 5-doctor facility, you're not go- 
ing to have a highly trained intubator, 
but at a place like Massachusetts Gen- 
eral Hospital or Harborview the equa- 
tion is absolutely clear. I would say 
that there are some added benefits in 
any case to having trained the respi- 
ratory therapists in the OR, because, 
in general, the respiratory therapists 
are usually among the first responders 
to a code, and I believe it has resulted 
in excellent initial bag-and-mask ven- 

Hurford: No argument there. Now, 
your current frequency of events cer- 
tainly isn't enough to keep up compe- 
tency. What sort of program do you 
have for continuing education of the 
respiratory therapists? 

Bishop: Gee, that's next year's pa- 
per! We're actually doing a study on 
that right now, and one of the things 
that I've proposed when we set this 
program up was that I wanted to set 
up a core group of maybe 8 therapists 
(2 for each shift) who would be trained 
and retrained and would be doing them 
to keep up competency. Our respira- 
tory therapy group managers wanted 

everyone to be trained, and it turns 
out they were probably right to insist 
that everyone get trained, because hav- 
ing a trained assistant is very useful. 
We have a core group who are doing 
most of the intubations, and we have 
another group of therapists who are 
trained but not really actively doing 
the intubations. This year we have re- 
quired everyone to come back for re- 
training and recertification. We're do- 
ing a study with an observer who 
determines which skills have and have 
not been retained, to see whether do- 
ing the intubations on the ward has 
resulted in enough retention of skills. 
Hopefully, we'll have more informa- 
tion about skill retention, but for the 
moment, we decided everybody had 
to come back to the OR for retraining. 
It's not a huge expense, but it's a fair 
bit of effort; it sometimes means push- 
ing aside the medical students and den- 
tal residents, or whoever has come to 
the operating room to intubate. 

Durbin: The following question is 
intended to be provocative. A promi- 
nent ethicist was concerned that by 
substituting respiratory therapists for 
anesthesiologists in emergency intu- 
bations, a hospital in New York was 
violating the Geneva Convention by 
experimenting on patients without 
their consent. Is this a concern about 
your study? Didn't you just substitute 
one process of care for another with- 
out any evidence that they were equiv- 
alent? In fact, you started off by say- 
ing it would be hard to show by any 
scientific method that they're really 
equivalent. I have heard you say at 
public meetings before that an anes- 
thesiologist is still the most skilled per- 
son in that environment. Is this change 
ethically acceptable without asking pa- 
tient consent? Lest there be any mis- 
understanding, I want to make it clear 
that 1 think therapists have a unique 
role in airway intubation in that they 
are credentialed, certified, and recer- 
tified to do the procedure. They are 
carefully watched under an organiza- 
tional process, whereas physicians and 


Respiratory Care • July 1999 Vol 44 No 7 

Who Should Perform Intubation? 

residents, in general, are not similarly 
certified. I think the therapist's care- 
ful preparation is a huge advantage 
for respiratory care. The most quali- 
fied person should be responsible for 
critical skills such as airway manage- 
ment, and therapists have a broad view 
of airway management, while most 
other physicians do not. Most patients 
are helped by expert management of 
the airway, not just by intubation, 
and 1 think that the global approach 
to airway management is the unique 
and important skill that respiratory 
therapists bring, and they definitely 
should be part of it. 

Bishop: I think you have to look at 
it as we do everything else. You look 
at the cost and benefits. I think we 
have certain requirements for Level 1 
trauma centers that we don't have for 
other hospitals. We calculated the like- 
lihood of what we thought was an ad- 
verse event, and felt that it fell within 
acceptable guidelines, but the truth is 
that I've had anesthesia residents on 
call in-house after 2 weeks of train- 
ing, and they were responsible for the 
airway. Now, the ones we put on call 
those first few days, we usually would 
call them in advance and ask them if 
they did rotations through anesthesia 
as a medical student, and we try to use 
the most trained ones, but still we're 
not talking about huge amounts of 
training. We now at least have quality 
control in advance — we have observed 
the therapists. I think the level of care 
is a lot higher than in many other places 
where whatever physician happens to 
show up may be attempting the intu- 
bation at a code. In fact, one signifi- 
cant problem we had to work through 
was first or second year medical res- 
ident saying "Oh, you're a respiratory 
therapist? /'// do the intubation." 
We've trained the respiratory thera- 
pists to say "No, the hospital policy is 
that I'm supposed to take care of that. 
If the anesthesiologist gets here and 
wants to supervise you, that's fine, but 
it's my job to do this." 

Thompson: I really like the way 
you've developed your program, in 
part because it makes me more com- 
fortable in our own transition from a 
physician-led transport team to a 
nurse/therapist team. You give me con- 
fidence that we're doing the right 
thing. I have concerns about the knowl- 
edge of some anesthesia residents. At 
least with respect to pediatric man- 
agement, I find that their ability to 
anticipate, recognize, and treat physi- 
ologic instability is limited. Do you 
see this? 

Bishop: Yes. I think I'd like to be 
there for a lot of the cases. Patients 
get intubated and ventilated, and sud- 
denly they're relatively hypovolemic. 
Yes, that's a problem. We try to edu- 
cate people. It's something we espe- 
cially try to make our therapists aware 
of, especially in the bronchospastic pa- 
tient — don't overventilate them. 

Thompson: It's most concerning 
when they take on the mantle of air- 
way expert, but fail to attend to the 
physiologic rather than technical as- 
pects of airway management. 

Bishop: One thing I think we've 
made very clear is that when the ther- 
apist is doing the intubation, they are 
there to do the intubation. But, most 
of the physiologic management of the 
patient is still up to the primary service, 
and I know I'll have some disagreement 
on that: I can tell you that from the last 
Journal Conference 1 attended, where 
therapist involvement in other aspects 
of resuscitation was a fairly controver- 
sial subject. But we've emphasized that 
that's really the primary service provider 
who is going to care for that. 

Thompson: In many hospitals there 
may be no formally trained person 
available to handle airway emergen- 
cies. What about the smaller commu- 
nity hospitals that don't have any phy- 
sicians in-house on a regular basis? 
What recommendations would you 
make for these institutions? What are 

the opportunities to spread your good 
efforts to more places? What can we 
do to develop a guideline or perhaps 
even a standard for hospitals? 

Bishop: I think the first problem 
with that is that it takes a lot of work 
from the anesthesiologists and the ther- 
apists. Another question is the finan- 
cial one. I think Medicare pays some- 
thing like $45 to $50 for an intubation. 
The intubation is going to take a couple 
hours of someone's time by the time 
they go in, assess the patient, write the 
note. etc. 1 would think that in small 
private hospitals there would be finan- 
cial disincentive to call someone in to 
intubate for a code call. I'm able to do 
it because I have residents on hand, but 
different models might have to be set 
up for the 80-bed hospital in rural Texas. 

Stauffer: Your excellent presenta- 
tion and this discussion raise questions 
about the whole issue of training, cre- 
dentialing, and proficiency for physi- 
cians in various disciplines in airway 
management. I'm thinking particularly 
about training in primary care fields 
like pediatrics, general internal medi- 
cine, family medicine, and so forth. 
To my knowledge, there aren't any 
national standards or guidelines that 
would indicate how much training a 
physician should have in intubation, 
how much in applying for staff priv- 
ileges in insfitutions, and how much 
in maintaining proficiency. To be pro- 
vocative, let me ask if we should even 
be training internal medicine residents 
in endotracheal intubation rather than 
in use of alternative airway methods 
such as laryngeal mask airways? 

Bishop: The reality for most of them 
is that they would be very unlikely to 
use that skill with any frequency. For 
the pulmonary fellows, we now re- 
quire an anesthesia rotation because 
they're going to be involved with some 
frequency. But, no. There's no national 
standard for anything. As you know, 
once a person receives an MD they 
can, legally speaking, go do hernia sur- 

Respiratory Care • July 1999 Vol 44 No 7 


Who Should Perform Intubation? 

gery tomorrow if they can get a hos- 
pital or ambulatory surgery facility to 
allow them on their staff. 1 think it would 
be impossible to legislate for every pro- 
cedure, but that's part of what hospital 
credentialing and privileging is about. 

Hurford: The problems you point 
out are important ones, and we face 
them as well. One response to them 
was a series of conferences that we 
had in 1994 and 1995 to establish 
guidelines for the Massachusetts Gen- 
eral Hospital, Brigham and Women's 
and Children's, Deaconess, and Bos- 
ton Children's Hospital anesthesia de- 
partments for endotracheal intubation. 
They were a bit more extensive than 
you use at the Veterans Administra- 
tion hospital in that our anesthesia re- 
sponders had to have at least 6 months 
of operating room experience prior to 
carrying the bag, which would be about 
300-400 endotracheal intubations or 
at least episodes of airway manage- 
ment. They did not respond to pedi- 
atric airways as a primary responder, 
just as a secondary responder. The pri- 
mary responder was always a pediat- 

ric intensivist (fellow or staff), with 
the anesthesia responder coming sec- 
ondarily on a clear chain of command 
to help the pediatrician. Board certi- 
fied surgeons and surgeons with 
greater than 3 years of operating room 
experience, were also permitted to han- 
dle the airway. We do not teach our 
anesthesiologists how to do cricothy- 
roidotomies or recommend jet venti- 
lation as a rescue method. Instead, we 
decided to focus our teaching on la- 
ryngeal mask airways. Interestingly, 
these guidelines have been adopted by 
all the various Harvard hospitals as 
our minimal standards for response to 

Bishop: It was nice you were able 
to set up those standards at Harvard 
hospitals, but in rural communities, 
that isn't going to work. 

Hurford: I agree. Standards or 
guidelines must be different for dif- 
ferent places. 

Stoller: I would like to make one 
comment that follows Dr Thompson's 

question, regarding the generic issue 
of how to extend best practices from 
larger centers to smaller institutions. 
Although there are many problems as- 
sociated with the amalgamation of 
health care institutions, there are also 
some opportunities. 

Watson: This is a complex issue; 
there's no real consensus, and there's 
a great deal of variation from group to 
group. This in mind, a rhetorical ques- 
tion: What is the difference between 
tracheal intubation and any otheremer- 
gency lifesaving procedure (for exam- 
ple, chest tube insertion, of which I've 
probably done 5 in my professional 
life and, despite this, feel very com- 
fortable doing)? Why do we expect 
more of our intubators in a code situ- 
ation than we do of the fellow who 
puts the pacemaker in? 

Durbin: My answer is that if you 
fail at intubation, everybody knows it, 
and the recriminations follow very 
quickly, whereas those other proce- 
dures are considered adjuvant to life. 


Respiratory Care • July 1999 Vol 44 No 7 

Managing the Artificial Airway 

Dean R Hess PhD RRT FAARC 


Assessing Proper Endotracheal Tube Position 

Recognition of Esophageal Intubation 

Recognition of Bronchial Intubation 
Securing the Endotracheal Tube 
Cuff Issues 
Secretion Clearance 



Airway Trauma 



Selective Bronchial Suctioning 

Increased Intracranial Pressure 

Coughing and Bronchospasm 
Closed Suction Catheters 
Saline Instillation 

[RespirCare 1999;44(7):759-772] Keywords: colorimetric capnometry, esoph- 
ageal detector device, endobronchial intubation, esophageal intubation, un- 
planned extubation, airway cuff pressure, airway cuff leak, endotracheal suc- 
tion, airway management. 


Management of the airway is one of the most important 
aspects of critical care practice. There is potential for se- 
rious morbidity and mortality related to mismanagement 
of the airway.' Airway complications can generally be 
avoided by appropriate attention to detail. Every critical 
care clinician has a responsibility to assess the airway and 
make appropriate interventions to avoid airway-related 
complications. This paper reviews assessing proper airway 

Dean R Hess is affiliated with Respiratory Care Services, Department of 
Anaesthesia and Critical Care, Massachusetts General Hospital, Harvard 
Medical School, Boston, Massachusetts. 

Correspondence: Dean R Hess PhD RRT FAARC. Respiratory Care 
Services, Ellison 401, Massachusetts General Hospital, 55 Fruit Street. 
Boston MA 02114. E-mail: 

position, securing the endotracheal tube, cuff-related is- 
sues, and secretion management. 

Assessing Proper Endotracheal Tube Position 

Misplacement of the endotracheal tube is a serious com- 
plication, and potentially life-threatening if not recog- 
nized.^-'' After placement, endotracheal tubes can become 
misplaced due to chewing, coughing, bucking, tongue 
movement, or head movement.' The tube can move ceph- 
alad into the pharynx and potentially into the esopha- 
gus, or caudad into a main bronchus (usually the right 

Recognition of Esophageal Intubation 

Several methods are used to differentiate esophageal 
and tracheal intubation (Table 1).*'** Unfortunately, none 
of these techniques is foolproof and all have been shown 

Respiratory Care • July 1999 Vol 44 No 7 


Managing the Artificial Airway 

Table 1 . Techniques to Differentiate Tracheal from Esophageal 

Direct visualization 

Chest movement 

Breath sounds 

Epigastric auscultation and observation 

Exhaled tidal volumes with spontaneous breathing 

Gastric contents in tube 

"Feel" of manual ventilation 

Condensation in tube 

Lighted stylette 

Chest x-ray 

Pulse oximetry 

End-tidal COj 

Esophageal detection device 


None of the techniques has been shown to be reHable in 

all circumstances. 







1 1 1 1 1 

I u n 








1 1 1 I n esophageal 

1 1 1 H 



U\\\ .™'°" 


Fig. 1. Capnogram from an animal with the endotracheal tube 
placed into the trachea and into the esophagus. (From Reference 
10, with permission.) 

to fail under certain circumstances. Assessing expired car- 
bon dioxide (COj) is considered by many to be the stan- 
dard for detection of esophageal intubation.'-" This ap- 
proach assumes that no COj is present in the stomach and, 
therefore, absence of exhaled COj indicates esophageal 
placement of the airway (Fig. 1). Quantitative and quali- 
tative approaches are available for COj detection.*'^ Fig- 
ure 2 shows a colorimetric end-tidal COj detector. This 
device uses paper impregnated with a pH-sensitive, non- 
toxic chemical indicator. The paper reversibly changes 
color in the presence of COj.'^"-^^ 

A limitation of COj detection methods is that exhaled 
COj concentration is determined, in part, by pulmonary 
blood flow. When pulmonary blood flow is low or absent, 
exhaled COj concentration is low or absent, and in this 
circumstance CO2 measurement cannot assist in the deter- 
mination of proper tracheal placement. 2** '♦^ 

A method that does not use CO2 detection is the esoph- 
ageal detection device (EDD).*^-,^ jhg eDD (Fig. 3) uses 
either a syringe or an inflatable bulb attached to the prox- 
imal endotracheal tube. If the endotracheal tube is in the 
esophagus, attempts to aspirate air from the tube should 
collapse the unsupported walls of the esophagus around 
the end of the endotracheal tube and create a vacuum in 
the endotracheal tube. If the tube is in the trachea, the 

Fig. 2. Colorimetric end-tidal CO2 detector used to assess endo- 
tracheal tube position. 

tracheal rings prevent tracheal collapse and air should be 
readily withdrawn from the tube. The accuracy of the EDD 
to differentiate tracheal from esophageal intubation has 
been reported by many investigators. The EDD accurately 
indicates esophageal intubation in nearly 100% of cases. 
Unfortunately, the EDD also indicates esophageal intuba- 
tion in some cases in which the endotracheal tube is cor- 
rectly placed in the trachea.'*''-''^-'''* The reasons for this 
false indication of esophageal intubation are unclear, but 
may relate to obesity, cuff inflation, or secretions in the 

Recognition of Bronchial Intubation 

A rate of endotracheal tube malposition as high as 30% 
has been reported.'''' The ideal position for the endotra- 
cheal tube is in the mid-trachea, 5 cm from the carina, with 
the head in a neutral position.''^ Endobronchial intubation 
leads to atelectasis of the nonventilated lung, hypoxemia, 
and hyperinflation of the contralateral lung. Conversely, 
care must be taken to prevent placement of the endotra- 
cheal tube too cephalad in the trachea, which can result in 
injury to the larynx upon cuff inflation. Techniques that 
are commonly used to detect endobronchial misplacement 
of the tube include auscultation, depth of insertion of the 
tube, bronchoscopy, and chest radiography. Cuff palpation 
in the suprasternal notch has also been used to confirm that 
the endotracheal tube tip is a safe distance from the cari- 
na.''^ In the cuff palpation method, the endotracheal tube is 
withdrawn or advanced while gentle digital pressure is 


Respiratory Care • July 1999 Vol 44 No 7 

Managing the Artificial Airway 




Fig. 3. A: Squeeze-bulb esophageal detection device. B: Syringe 
esophageal detection device. C: Squeeze bulb esophageal detec- 
tion device attached to endotracheal tubes placed into the trachea 
(left) and the esophagus (right). Note that the bulb on the tube 
placed into the esophagus (right) does not inflate. (Fig. 3C from 
Salem MR, Wafai Y, Joseph NJ, Baraka A, Czinn EA. Efficacy of 
the self-inflating bulb in detecting esophageal intubation: does the 
presence of a nasogastric tube or cuff deflation make a differ- 
ence? Anesthesiology 1994; 80(1):42-48, with permission.) 

applied to the suprasternal space. The pilot balloon is si- 
multaneously palpated with the other hand. When the pilot 
balloon distends with pressure applied to the suprasternal 
notch, the tube is secured. Comparison of this method to 
chest radiography or bronchoscopy has not been reported. 
Of concern is that this method could result in placement of 
the tube at a position too cephalad in the trachea, which 
could result in cuff injury to laryngeal structures. 

Guidelines have been published for proper depth of in- 
sertion of endotracheal tubes. For orotracheal tubes, Ea- 
gle^^ suggested the following depth of insertion: 

teeth to midpoint of trachea = height (cm)/ 10 -I- 2 

For nasotracheal tubes, the following was suggested by 

external naris to midpoint of trachea = 
height (cm)/ 10 + 8 

Owen and Cheney'''^ examined endotracheal tube position 
in 388 men and 190 women admitted to a critical care unit. 
They reported that securing endotracheal lubes at the 23 
cm mark in men and the 21 cm mark in women (measured 
at the upper incisor teeth or gums) significantly reduced 
the likelihood of endobronchial placement. These results 
have been confirmed by others.*" 

Several studies have compared physical assessment with 
radiographic determination of endotracheal tube position. 
Gray et al''' reported a 30% incidence of endotracheal tube 
malposition, as determined by chest radiograph. Brunei et 
al aF reported that 14% of patients required endotracheal 
tube repositioning based on radiographic findings follow- 
ing intubation in the intensive care unit (ICU) and 5% had 
endobronchial intubation. Schwartz et aH reported an en- 
dotracheal tube malposition rate of 15.5% of emergency 
intubations performed in an ICU, with a greater risk for 
malpositioning in women. These data suggest that, al- 
though physical findings are useful in determination of 
endotracheal tube position, with many patients a chest 
radiograph is necessary to correctly position the endo- 
tracheal tube. 

The position of the endotracheal tube changes with 
changes in head position (Fig. 4). Conrardy et al"' found 
that the distal tip of the endotracheal tube moves about 2 
cm toward the carina with flexion of the neck and about 2 
cm away from the carina with neck extension. Thus, 
knowledge of head and neck position is important for 
proper radiographic interpretation of endotracheal tube 

KoUef et aP reported a 46% incidence of endotracheal 
tube misplacement in 246 patients, and that 74% of all 
endotracheal tube misplacements occurred after the day of 
initial intubation. This suggests that endotracheal tube po- 
sition should be assessed regularly. When proper endotra- 
cheal tube position has been established, the distance mark- 
ing on the endotracheal tube (measured at the upper teeth 
or gums for oral intubation or at the external naris for nasal 
intubation) should be recorded. This measurement should 
be reconfirmed on a regular basis (eg, every 8-12 hours) 
or with any intervention that might cause tube movement 
(eg, change of patient position, patient transport, move- 
ment of tube during mouth care, resecuring the tube). 

Respiratory Care • July 1999 Vol 44 No 7 

76 J 

Managing the Artificial Airway 

hard palate 

base of 




endotracheal p-j 

tube ^^^ 

neutral extension 


Fig. 4. A: The effect of flexion and extension of the neck on en- 
dotracheal tube movement. (From Reference 61 , with permission.) 
B: With flexion and extension of the neck, the tip of the endotra- 
cheal tube can move about 2 cm in either direction. (From Refer- 
ence 61 , with permission.) 

Securing the Endotracheal Tube 

An important aspect of airway management is adequately 
securing the tube to avoid accidental extubation or move- 
ment into a main bronchus. Unplanned extubation (acci- 
dental extubation or self-extubation) rates of 2-13% have 
been reported.*-'^" Although reintubation is not necessary 
for every case of unplanned extubation, the reintubation 
rate for unplanned extubation is greater than that for planned 
extubation. ''^•'^•''•* Unplanned extubation can result in se- 
rious complications, and deaths have been reported.*^'^* 
Using multivariate analysis, Boulain''^ identified 4 factors 
contributing to unplanned extubation: (1) chronic respira- 
tory failure, (2) orotracheal intubation, (3) lack of intra- 
venous sedation, and (4) endotracheal tube fixation with 
only thin adhesive tape. Quality improvement programs 
have been reported to decrease the incidence of unplanned 
extubation. ^■''2-7''-7<' A common feature of these programs 
was an improved method for securing the endotracheal 

Several methods are used to secure endotracheal 
tubes. <'2.77- 86 One common and inexpensive method uses 
adhesive cloth tape around the tube, upper lip, and face.^^ 

The adhesive tape strength on endotracheal tubes varies,^'' 
so it is important to use a tape that adequately adheres to 
the endotracheal tube. One-inch tape is cut long enough to 
go around the circumference of the patient's head 1.5-2 
times. So as to prevent the tape from sticking to the pa- 
tient's neck, a second piece of tape is cut long enough to 
fit over the midportion of the first piece, thus creating a 
section with no adhesive showing on either side. The tape 
is then placed around the patient's neck. The skin surface 
is dried and tincture of benzoin is placed on both cheeks 
where the tape will contact the skin. The tape is pulled 
snug against the neck and applied on the patient's cheeks 
up to the edge of the endotracheal tube. The remaining 
tape is split longitudinally so that at least two inches of 
tape is available to be wrapped around the endotracheal 
tube at the lips. The end of the tape can be folded back on 
itself to form a tab, which facilitates later removal of the 
tape. Some clinicians wrap both ends of the split tape 
around the tube, whereas others wrap one piece around the 
tube and the other piece is passed over the lip and fastened 
to the contralateral cheek. Care is taken to apply the tape 
snugly but not so tight as to produce facial skin break- 
down. The advantage of this method is that the tape passes 
completely around the neck — a method that is usually pref- 
erable to techniques in which one or two pieces of tape are 
used to tape the tube to the patient's cheeks. A similar 
method can be used for nasally placed tubes. The endo- 
tracheal tube, gastric tube, and oral airway (if present) 
should be separately taped so that one device can be re- 
positioned or removed without affecting the other. The 
tube should not be affixed to the mandible, because doing 
so increases the likelihood of tube movement resulting 
from jaw movement. Although a bite block (an oral airway 
is commonly used for this purpose) is useful to prevent 
biting on the tube, this is often not needed. The bite block 
decreases patient comfort and makes effective mouth care 
more difficult. 

Another common technique for securing the endotra- 
cheal tube uses twill tape.'** With this method, a 1 -meter 
length of twill tape is folded in half and looped around the 
endotracheal tube. The ends are brought through this loop 
and tightened around the tube. One end of the twill tape is 
passed around the patient's head below one ear and the 
other end is passed above the other ear. The two ends are 
tied in a bow on the cheek. Sometimes this is repeated with 
a second piece of twill tape so that two ties are used to 
secure the endotracheal tube. Barnason et al'*'' compared 
the use of twill tape and adhesive tape to secure endotra- 
cheal tubes, and reported that these methods are compa- 
rable in preventing unplanned extubation and maintaining 
oral mucosal and skin integrity. 

Several devices for securing endotracheal tubes are com- 
mercially available.''''-^'* The principal advantage of these 
is the speed with which they can be applied, and they are 


Respiratory Care • July 1999 Vol 44 No 7 

Managing the Artificial Airway 

therefore popular for field use. For the ICU, the adhesive 
tape or twill tape approach is effective and inexpensive. 
Some designs of commercial endotracheal tube holders 
can make certain procedures more difficult (eg, prone po- 

Securing the endotracheal tube can be particularly prob- 
lematic in burn patients, who often have facial swelling 
and may have burn injuries to the face and head. Achauer 
et al**** described methods in which the endotracheal tube is 
affixed to a wire that is anchored to a tooth, several teeth, 
the nasal spine, or the mandible. Perrotta et al**'' reported a 
similar method for children with facial burns, in which the 
tube is attached to a standard dental arch bar that is se- 
cured to maxillary teeth with stainless steel wire. Note that 
these approaches have the potential to cause dental injury, 
and make it more difficult to remove the tube in emer- 
gency situations (eg, if the tube becomes occluded). 

The position of the endotracheal tube in the mouth should 
be adjusted periodically to provide mouth care and to pre- 
vent pressure sores to the lips, gums, or mouth. Two peo- 
ple should be present when the endotracheal tube is unse- 
cured for this care: one is responsible for maintaining tube 
position and the other is responsible for providing mouth 
care and resecuring the tube. In some units, it is common 
practice to trim the excess endotracheal tube length, which 
decreases the risk of tube malposition or kinking; how- 
ever, it is important to determine that the tube is properly 
positioned before trimming. A swivel connector between 
the endotracheal tube and the breathing circuit should be 
used, and there should be support for the breathing circuit 
so that it does not promote tube movement. 

Cuff Issues 

High tracheal wall pressures exerted by the inflated cuff 
of the endotracheal or tracheostomy tube can produce tra- 
cheal mucosal injury.''"'^* The tracheal capillary perfusion 
pressure is normally 25-35 mm Hg. Because the pressure 
transmitted from the cuff to the tracheal wall is usually 
less than the pressure in the cuff, it is generally agreed that 
25 mm Hg (34 cm HoO) is the maximum acceptable in- 
tracuff pressure. If the cuff pressure is too low, silent 
aspiration is more likely. '"o"" Bemhard et al"" reported a 
greater risk for aspiration with cuff pressures less than 1 8 
mm Hg (25 cm HjO). Based on this evidence, it seems 
reasonable to maintain cuff pressures at 20-25 mm Hg 
(25-35 cm HiO) to minimize the risks of tracheal wall 
injury and aspiration. Cuff pressure is affected by airway 
pressure, and cuff pressure increases linearly with airway 
pressure. '"- 

The cuff is typically inflated using a minimum occlu- 
sion pressure or a minimum leak technique."""" With the 
minimum occlusion pressure method, the cuff is inflated to 
a volume that just eliminates an end-inspiratory leak dur- 


Fig. 5. Equipment set-up to measure cuff pressure. (From Refer- 
ence 105, with permission.) 

Digital P-V Gauge* 


Fig. 6. Commercially available device to measure cuff pressure. 

ing positive pressure ventilation. With the minimum leak 
technique, the cuff is inflated with a volume that allows a 
small leak to occur at end-inspiration. With either method, 
a leak around the cuff is assessed by auscultation over the 
suprasternal notch or the lateral neck. Although no com- 
parison of these approaches to cuff inflation have been 
reported, it may be prudent to use a minimal occlusion 
pressure to decrease the risk of silent aspiration of pha- 
ryngeal secretions. 

Monitoring cuff pressure is a standard for respiratory 
care practice. Intracuff pressure should be monitored and 
recorded at least once per shift, and more often if the tube 
position is changed, if the volume of air in the cuff is 
changed, or if a leak occurs.**'' Cuff pressure is measured 
with a syringe, stopcock, and manometer (Fig. 5),"''' '"<' 
which allows simultaneous measurement and adjustment 
of cuff pressure. Methods in which the manometer is at- 
tached directly to the pilot balloon are discouraged be- 
cause they cause air to escape from the cuff to pressurize 
the manometer. Commercially available systems can also 
be used to measure cuff pressure (Fig. 6). 

A common cause of high cuff pressure is the selection 
of too small an endotracheal tube, in which case higher 
cuff pressure is needed to achieve a seal. If the volume of 
air in the cuff required to achieve a seal exceeds the nom- 
inal volume of the cuff, the selected endotracheal tube size 
is too small. The nominal cuff volume is the volume below 
which the cuff pressure is < 25 mm Hg ex-vivo. Another 
common cause of high cuff pressure is malposition of the 

Respiratory Care • July 1999 Vol 44 No 7 


Managing the Artificial Airway 

, severed one-way valve and inflating tube 


Fig. 7. Method to maintain cuff pressure if 1-way valve and inflat- 
ing tube are severed. (From Reference 107.) 

endotracheal tube, particularly cephalad positioning, in 
which the cuff is inflated in the larynx or pharynx. Other 
causes of high cuff pressure include overfilling of the cuff, 
tracheal dilation, and use of a low-volume high pressure 

Occasionally, the pilot tube may be severed. To correct 
this problem, a short blunt needle can be passed into the 
pilot tube and a stopcock attached to the needle hub to add 
and maintain air in the cuff until the tube can be replaced 
(Fig. 7). 107.108 Cuff leaks can also occur, and a continuous 
flow of gas into the cuff can be used to temporarily main- 
tain cuff inflation until the tube can be changed.""^ 

Kearl et al"" reported that a large number of endotra- 
cheal tubes removed for presumed cuff rupture were ac- 
tually flawless. They speculated that tube malposition might 
be the reason clinicians sometimes incorrectly conclude 
that the cuff has ruptured. The cuff inflation method shown 
in Figure 5 represents a simple way to determine cuff 
rupture. If a leak occurs during this maneuver, there may 
be a ruptured cuff or incompetent pilot balloon. The cause 
of an observed leak can be further assessed by clamping 
the pilot tube. If a leak disappears with the clamp in place, 
then the pilot balloon or valve is incompetent. Figure 8 
shows an algorithm for cuff management. 

Secretion Clearance 

Intubated patients should be suctioned whenever phys- 
ical examination reveals the presence of secretions in the 
airway." '"2 Because suctioning is an uncomfortable and 
potentially hazardous procedure, it should be performed 
only when indicated, and not at a fixed frequency."^ The 
upper airway should also be suctioned periodically to re- 
move oral secretions. 

Several general features apply to all suction catheters: '"'"^ 
(1) they should be long enough to enter the mainstem 

bronchi — usually 22 inches (56 cm); (2) a thumb port is 
provided at the proximal end of the catheter to control 
suction to the catheter; (3) the catheter must be rigid enough 
to allow passage through an artificial airway, but flexible 
enough to prevent damage to the airway mucosa; (4) to 
prevent damage to the airway mucosa, the catheter should 
also have smooth, molded ends, one or more side holes 
near the catheter tip, minimal frictional resistance when 
passed through the airway; and (5) the catheter should be 
transparent so that the aspirated secretions can be assessed. 
There are numerous recognized potential complications of 
airway suctioning,' ' '"4' is ^jj^j g suction technique should 
be used to minimize these complications. 


The causes of suction-related hypoxemia are: (1) inter- 
ruption of mechanical ventilation during the suctioning 
procedure (loss of ventilation, inspired oxygen, and posi- 
tive end-expiratory pressure), (2) the aspiration of gas from 
the respiratory tract during the application of suction, (3) 
the entrainment of room air into the lungs, (4) the duration 
of the suction procedure, and (5) suction-related atelecta- 
gjg 111,116-121 Hyperoxygenation is the best technique to 
avoid suction-related hypoxemia, and should be used with 
all suction procedures. '^-'-'^ This is most commonly ac- 
complished by increasing the fraction of inspired oxygen 
(Fio,) to 1 .0, but increasing the F|o, by 0.20 may be ade- 
quate. '^^ 

Hyperinflation and/or hyperventilation to prevent suc- 
tion-related hypoxemia'^** should be used cautiously be- 
cause of the possibility of over-distention lung injury.'-** A 
recruitment maneuver (eg, 40 cm HjO for 40 seconds) 
following the suction procedure has been recommended, 
particularly for patients with acute respiratory distress syn- 
drome requiring high levels of positive end-expiratory pres- 
sure.'-''" In some critical care units, a manual ventilator 
(resuscitator) is used for hyperinflation and hyperoxygen- 
ation during suctioning procedures. Several studies report 
that this method might be inferior to hyperinflation and 
hyperoxygenation using the ventilator.'""''''' It has also 
been shown that manual ventilators found at the bedside of 
mechanically ventilated patients can be a source of con- 
tamination of the lower respiratory tract.'""' One of the 
difficulties related to use of a manual ventilator during 
suctioning is that tidal volume delivery and airway pres- 
sure are not usually measured. Singer et al'-^'' reported that 
lung hyperinflation is frequently not achieved by manual 
ventilation, and that adverse hemodynamic sequelae can 
result if hyperinflation is achieved. Glass et al'"''' reported 
that when nurses used a manual ventilator during endotra- 
cheal suctioning, the mean F,o, was 0.71, the mean respi- 
ratory rate was 3 1 breaths per minute, and the mean tidal 
volume was 626 mL. 


Respiratory Care • July 1 999 Vol 44 No 7 

Managing the Artificial Airway 

assess for presence 

of leak around cuff; at 

_^ least once per shift, with tube 

movement, with gross leak, or 

when cuff volume is changed 

no leak 

20 -25 mm Hg 


- assess cuff pressure - 

leak present add air .^ 
to cuff 

< 20 mm Hg 

I >25 mm Hg 

no leak 

remove air from cuff 
until pressure is 25 mm Hg 

assess for presence 

of leak around cuff 

leak present 


^ ^° ^^^^ — — ^ assess tube position- 


I position satisfactory 

assess tube size- 


size appropriate 

small tube change to larger 

size if possible 

set cuff pressure 
at 25 mm Hg ■♦ 

assess for leak in cuff system; add 
air to cuff and assess cuff pressure 


pressure loss 
I yes 


add air to cuff and 

clamp pilot tube 

I no leak 

place stop cock on pilot 
balloon; remove clamp ' 

no leak 

incompetent 1 -way valve - 
Fig. 8. Algorithm for management of the endotracheal tube cuff. 



_^ ruptured cuff; 
change tube if possible 

incompetent pilot balloon; 

-► change tube if possible or ► 

clamp pilot tube 

change tube if possible or 
"^use stop cock on pilot balloon 

The duration of suction also affects the degree of hy- 
poxemia.'-" The duration of a suction attempt should be as 
short as possible. The suction procedure should be termi- 
nated at 15 seconds, with resumption of ventilation and 


Atelectasis during suctioning can occur as the result of 
evacuation of gases from the lower respiratory tract. This 
is more likely when excessive suction pressures are used 
and when the size of the suction catheter is large in rela- 
tion to the size of the endotracheal or tracheostomy tube.'^^ 

The suction pressure should be no greater than required to 
adequately remove secretions, and not greater than 100 
mm Hg for infants, 125 mm Hg for children, and 150 mm 
Hg for adults. Suction catheters are available in a variety 
of sizes. Catheter size is determined by outside diameter in 
French units, which refers to the circumference of the 
tube. Because circumference equals the value of tt (3.14) 
multiplied by the diameter, French size can be estimated 
by multiplying the diameter times 3. The outside diameter 
of the suction catheter should not exceed V2--A of the 
inside diameter of the artificial airway. A 14-F catheter is 
usually acceptable for adult patients. Too small a catheter 
will limit the effectiveness of secretion removal, but too 
large a catheter will increase the risk of complications. 

Respiratory Care • July 1999 Vol 44 No 7 


Managing the Artificial Airway 

Airway Trauma 

Airway edema, hyperemia, mucosal ulceration, hemor- 
rhage, and decreased mucociliary transport have been re- 
ported with airway suctioning. '^'^•''"' These effects are re- 
lated to operator technique and the amount of suction 
pressure used. Intermittent suction, rather than continuous 
suction, may be less traumatic to airway mucosa, but there 
is little evidence for this.""-"'^ The catheter tip should be 
smooth, molded, and atraumatic. ''*''■*■' Side holes near the 
tip of the catheter minimize trauma to the airway mucosa. 
Pneumothorax secondary to bronchial perforation by a suc- 
tion catheter has been reported in infants.'-*'' '•*'' In infants, 
the suction catheter should not be inserted more than one 
cm beyond the tip of the endotracheal tube. '•"*■'■*'' A similar 
practice should be used for patients with recent tracheal 
reconstructive surgery or pneumonectomy. 





catheter in 


Fig. 9. Closed suction system. 


Contamination of the lower respiratory tract can occur 
during tracheal suctioning, but this complication can be 
avoided by using sterile technique during the procedure. 
Care must be taken during suctioning to avoid contami- 
nation of the suction catheter, the ventilator circuit, or the 
valve of the manual ventilator. Care should also be taken 
to avoid contamination of the clinician performing the 


Arrhythmias can occur during tracheal suctioning, ''^"-'"'^ 
possibly as a result of hypoxemia or vagal stimulation. 
This complication can often be avoided by hyperoxygen- 
ating the patient during suctioning. Aerosolized atropine 
has also been used to prevent suction-related arrhythmias. ' ^ ' 

Selective Broncliial Suctioning 

Because the left main bronchus has a smaller diameter 
than the right and leaves the trachea at a more acute angle, 
the suction catheter is more likely to enter the right main 
bronchus.'''-' Therefore, secretions are more likely to be 
suctioned from the right lung than the left. Several tech- 
niques can be used for selective endobronchial suctioning 
(particularly the left bronchus). These include the use of 
curved tip catheters,'^''-''''* turning the head to the side''''"'" 
(eg, turning the head to the right to facilitate suctioning of 
the left bronchus), and lateral positioning"'' (eg. turning 
the patient onto the left side to facilitate passage of the 
catheter into the left main bronchus). The most successful 
method for selective endobronchial suctioning is the use of 
a curved-tip catheter. If a curved-tip catheter with a guide 
mark is used, successful endobronchial placement rates of 

nearly 90% have been reported. '""'' Factors that affect the 
success rate of selectively introducing a catheter into a 
main bronchus include ( 1 ) the anatomy of the carinal bi- 
furcation, (2) the body and head position of the patient, (3) 
the route of tracheal tube placement (endotracheal or tra- 
cheostomy), (4) the shape and direction of the bevel of the 
endotracheal tube, (5) the configuration and rigidity of the 
suction catheter, and (6) the location of the tip of the 
endotracheal tube.'-'''' Curved tip catheters may be more 
effective with tracheostomy tubes than with endotracheal 
tubes. '5S-' 59 

Increased Intracranial Pressure 

Increased intracranial pressure (ICP) can occur during 
tracheal suctioning, "'2-"'' which can be clinically impor- 
tant in patients with closed head injuries. When suctioning 
patients ICP is being monitored, ICP should be 
observed closely during the suctioning procedure. Preoxy- 
genation, hyperventilation, and pharmacologic support may 
be necessary when suctioning patients with elevated ICP. 

Coughing and Broncliospasm 

Tracheal suctioning is very irritating and uncomfortable 
for the patient. The presence of the catheter in the trachea 
can induce coughing, and may stimulate bronchospasm in 
patients with reactive airways."'**"'* 

Closed Suction Catheters 

With the closed suction system (Fig. 9) the catheter 
becomes part of the ventilator circuit. Closed system suc- 


Respiratory Care • July 1999 Vol 44 No 7 

Managing the Artificial Airway 

Table 2. Indications for Use of Closed Suction 

■ High ventilator requirements: positive end-expiratory pressure >I0 
cm HjO, mean airway pressure a20 cm H2O, inspiratory time 
> 1 .5 s, fraction of inspired oxygen &0.60 

• Mechanically ventilated patients receiving frequent suctioning (a6/ 


• Hemodynamic instability associated with ventilator disconnection 

• Mechanically ventilated patients with active tuberculosis 

• Patients receiving inhaled agents that cannot be interrupted by 

ventilator disconnection (eg. nitric oxide, heliox) 

tion catheters are available from several manufacturers — in 
adult, pediatric, and neonatal sizes. '^"'''^ The effective- 
ness of secretion clearance is similar for closed system 
catheters and conventional suction technique.'^-* In some 
hospitals, the use of closed suction catheters has been an 
emotional issue. At the Massachusetts General Hospital, a 
committee of respiratory therapists, nurses, physical ther- 
apists, and physicians recommended the indications for 
closed suction catheters listed in Table 2. 

Several studies have evaluated the ability of closed suc- 
tion to maintain adequate oxygenation during suctioning. 
Craig et al'^' evaluated the effect of ventilator mode with 
the use of closed suction. They found that with preoxy- 
genation, desaturation did not occur with either assist/con- 
trol or intermittent mandatory ventilation when a closed 
suction catheter was used. Without preoxygenation, how- 
ever, desaturation occurred on assist/control ventilation — 
but not on intermittent mandatory ventilation — when the 
closed system catheter was u.sed. These data are supported 
by a bench study that reported that closed suction can 
produce large intermittent drops in airway pressure, par- 
ticularly with a low inspiratory flow setting and in the 
control mode.'^'' Carlon et al'^^ reported no clinically im- 
portant difference in oxygenation between a closed system 
catheter and a conventional suction technique, even in 
patients receiving > 10 cm HjO positive end-expiratory 
pressure. Clark et al'''** found that mixed venous oxygen- 
ation was higher in patients suctioned with closed suction, 
and Mattar et al'^"* reported better oxygen delivery with 
closed suction compared to open suction. Johnson et al"*" 
reported that closed suction produced significantly fewer 
physiologic disturbances (such as dysrhythmias and de- 
saturation) than open suction. Harshbarger et a!"*' reported 
that use of a closed suction catheter without hyperoxygen- 
ation prevented desaturation in most, but not all, patients. 
The incidence of both patient contamination and environ- 
mental contamination has been reported to be less with the 
use of closed suction systems. "*--'**■* 
( A problem that has been reported with closed suction 
catheters is the catheter remaining in the airway following 
a suction procedure, or migrating into the airway between 
suction procedures.'**'' This can be of particular concern 

during pressure ventilation, in which the patient's tidal 
volume could be considerably compromised. Care must 
also be taken to avoid accidental patient lavage when the 
catheter is rinsed with saline. 

Although the closed catheter system costs many times 
more than a conventional suction catheter, it is used for 
many more suctioning attempts than a conventional cath- 
eter.'™ One study reported a cost savings of $6,600 in one 
year when closed suction was substituted for an open suc- 
tion procedure."*^ Johnson et al"*" reported that closed 
suction costs $1.88 per patient per day less than open 
suction, and that closed suction required 60 seconds less 
clinician time than open suction. 

Manufacturers recommend changing closed suction cath- 
eter systems on a daily basis. However, recent evidence 
suggests that this practice is not necessary. Kollef et al"*'' 
compared daily change to no routine change of closed 
suction catheters, and found no significant differences in 
hospital mortality, length of stay, or ventilator-associated 
pneumonia. Further, they reported large cost savings with 
the practice of no routine closed suction catheter changes. 
At the Massachusetts General Hospital, we compared daily 
and weekly changes of closed suction catheters in our 
medical ICU,"*** and found no difference in ventilator- 
associated pneumonia between the groups, and a signifi- 
cant cost savings with weekly changes of the closed suc- 
tion system. Our current practice is to change both ventilator 
circuits'**'' and closed suction'**** systems weekly. 

Saline Instillation 

Saline is often instilled into the airway as part of the 
suction procedure to facilitate the removal of secre- 
tions.'''"''^' However, this practice is controversial. ''^- Typ- 
ically, more saline is instilled than is retrieved by subse- 
quent suction attempts. This may result in an increase in 
the volume of secretions and a worsening of airway ob- 
struction. Ackerman''^"* reported that saline instillation dur- 
ing suctioning had an adverse effect on arterial oxygen 
saturation. Hagler and Traver''*'' reported that a 5 mL sa- 
line instillation dislodged large numbers of bacteria from 
the endotracheal tube lumen, thus increasing the likelihood 
of washing organisms from the endotracheal tube into the 
lower respiratory tract. Saline instillation may be useful to 
loosen and remove thick secretions in certain patients, but 
this procedure should be used judiciously and should not 
be a routine procedure. 


Managing the airway is an important aspect of respira- 
tory care practice. It involves attention to detail, such as 
regular assessment of tube position, adequately securing 
the endotracheal tube, and monitoring cuff pressure. Man- 

Respiratory Care • July 1999 Vol 44 No 7 


Managing the Artificial Airway 

aging the airway should also protect the patient from harm 
due to inappropriate cuff pressure, inadvertent extubation, 
and suction-related complications. 


I would like to thank the respiratory therapists and physicians at the 
Massachusetts General Hospital, who have taught me much about airway 
management. In particular, I would like to thank Ray Rilz, who has been 
a friend and who has appropriately tempered my ideas and enthusiasm 
with reason and prudence. 


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Heffner: Nice presentation. Dean. 
Let me ask you about measuring cuff 
pressures. There's a lot of controversy 
around the country as to whether we 
should measure cuff pressures and 
what we should do with the informa- 
tion. When patients are running very 
high cuff pressures, are we docu- 
menting potential difficulties from 
medical and legal standpoints? I 
agree with all of your comments, but 
others don't necessarily agree. What 
do you do in the ICU when you have 
a patient whom you're rounding on 
and you realize that to maintain a 
seal you have to tolerate high cuff 

Hess: We would have our respira- 
tory therapist discuss that with the team 

caring for that patient. Then the issue 
is how comfortable does the team feel 
about reintubating the patient, if the 
problem might be that the tube is too 
small. Or, we may try to determine 
whether this is an issue with some air- 
way anomaly, and maybe the tube 
needs to be repositioned so that we 
can get a seal with a lower cuff pres- 
sure. I think that, typically, the issue 
that would come up is whether a pa- 
tient needs to be reintubated with a 
larger tube so that we can achieve a 
seal with a lower pressure, and then, 
how comfortable does everyone feel 
about reintubating that patient with a 
minimum of risk. How do you address 
the issue? 

Heffner: Some physicians have told 
me that they'd rather not document 
cuff pressures, preferring to use min- 

imal leak technique or just go ahead 
and inflate until they have a good seal 
so that they don't discover the prob- 
lem and then have to document it. To 
me, it's really a spurious logic. Med- 
ically and legally it is better to docu- 
ment a problem and then justify the 
existence of that problem and why it's 
still best practice to maintain a high 
cuff pressure in a specific patient. I 
counsel people to do the same thing 
you do, which is to determine why the 
cuff pressure is elevated and why that 
might be necessary, or what they can 
do about it. Sometimes putting a larger 
tube in is important — sometimes put- 
ting a smaller tube is important if the 
cuff can't inflate to its full capacity 
and function the way it's supposed to 
in the airway. Occasionally, we have 
to reposition a tube at a different level. 
Also, it might be all right with some 


Respiratory Care • July 1 999 Vol 44 No 7 

Managing the Artificial Airway 

patients to tolerate a leak that may not 
cause a problem if they are intubated 
primarily for ventilatory respiratory 
failure rather than hypoxic respiratory 

Hess: I think you bring up another 
important issue. The important thing 
is the pressure the cuff actually ap- 
plies to the tracheal wall. If you have 
a very high cuff pressure but there is 
still a leak, the question is whether the 
cuff is producing any injury to the tra- 
cheal wall, since, even though pres- 
sure inside the cuff may be very high, 
if there is a leak, that indicates that the 
cuff is not in full contact with the tra- 
cheal wall, so, how could it injure the 
tracheal wall? That's actually a dis- 
cussion I get into sometimes with our 
respiratory therapists, who, appropri- 
ately, get concerned if the cuff pres- 
sure is high. But if there's still a leak, 
how could high cuff pressure be caus- 
ing a problem? 

Heffner: So, it's really the cuff ten- 
sion against the wall rather than the 
intracuff pressure that's important. 

Ritz: John, another important thing 
to realize regarding the routine mon- 
itoring of cuff pressure is that there 
are some indications that clinicians 
who don't have cuff manometers and 
are more concerned about leaks around 
the endotracheal tube may inadver- 
tently overpressurize cuffs, and that 
routine monitoring and limiting the 
number of people with access to the 
cuff lowers the incidence of tracheal 
injury. I think routine monitoring is 
probably a good idea. My read on the 
situation is similar to Dean's; I think 
we should use routine monitoring to 
prevent high cuff pressures. The high 
cuff pressures aren't because some- 
one has indiscriminately overin- 
flated it, but because of some other 

Heffner: I agree. 

Thompson: In my hospital we're in 
the midst of a discussion about the 
right way to conduct suctioning. Spe- 
cifically, do you pass the catheter be- 
yond the end of the endotracheal tube? 
I'm interested in other people's expe- 
rience and opinion about the impor- 
tance of shielding the tracheal mucosa 
from the catheter vs improved clear- 
ance of secretions after deep suction- 

Hess: 1 think the common teaching, 
and what I have taught over the years, 
is that for adults the suction catheter is 
passed until it meets resistance, and 
then is pulled back a centimeter and 
suction conducted from that point. I 
do know of literature that suggests that 
is not a good practice. '""^ In fact, in 
the neonatal and pediatric literature 
there have been reports of pneumo- 
thoraces associated with the passage 
of suction catheters past the tip of the 
endotracheal tube. Ray (Ritz) can cor- 
rect me if I'm wrong, but I think that 
at Massachusetts General Hospital our 
practice in the neonatal ICU is that the 
tip of the suction catheter is not passed 
beyond the tip of the endotracheal tube. 


1. Bailey C. Kattwinkel J, Teja K, Buckley 
T . Shallow versus deep endotracheal suc- 
tioning in young rabbits: pathologic ef- 
fects on the tracheobronchial wall. Pedi- 
atrics 1988;82(5):746-751. 

2. Anderson KD, Chandra R. Pneumothorax 
secondary to perforation of sequential 
bronchi by suction catheters. J Pediatr 
Surg 1976;ll(5):687-693. 

3. Grosfeld JL, Lemons JL, Ballantine TV, 
Schreiner RL . Emergency thoracotomy 
for acquired bronchopleural fistula in the 
premature infant with respiratory distress. 
J Pediatr Surg 1980;15(4):416-42l. 

Thompson: Actually, I'm more con- 
cerned about older infants and chil- 
dren, but would be interested in what 
the approach in adults is. Is your ap- 
proach widely accepted or is it con- 
troversial? It matches what I was 
taught to do, but recent observations 
of tracheal injury by the catheter have 

led many people to advocate limiting 
the passage of the catheter. 

Hess: The other patient population 
where that's a problem is in Bill Hur- 
ford's unit with the pneumonectomies 
and tracheal reconstruction patients 
where we're real careful about how 
far we pass the suction catheter. But I 
think that, beyond that, the typical 
practice is to pass the catheter until 
there's resistance and then pull back a 
centimeter or so and suction from that 

Stauffer: I think that's a reasonable 
practice, considering that we're often 
trying to evacuate secretions that are 
deep in the lower lobe bronchi. We 
often see, for example, left or right 
lower lobe atelectasis. In the absence 
of air bronchograms, we presume that 
mucus plugging has occurred, so deep 
suctioning is performed. I don't know 
how effective it is. 

Hess: The other issue about deep 
suctioning is that the suction catheter 
is only about 22 inches long. It's not 
very long. So the suction catheter prob- 
ably does well to get much past the 
carina. I don't think we do a lot of real 
deep suctioning. 

Hurford: I would agree with that, 
especially since the advent of respira- 
tory therapy-directed or -managed 
bronchoscopy services. So we have 
ready access to bronchoscopic suction- 
ing. Our problems with deep suction- 
ing aren't as large, and, to echo your 
point, we do limit catheter insertion 
when there is a bronchial stump or a 
lobectomy or an anastomotic line in 
the tracheobronchial tree. 

Watson: I'm interested in this prob- 
lem of cuff leak, since this is one of 
those classic situations where the ther- 
apists call us and we come to help out. 
I think it is the case that many of those 
leaking tubes (you cited a study show- 
ing 20% or so), have perfectly normal 
cuffs. The problem, really, is tube 

Respiratory Care • July 1999 Vol 44 No 7 

Managing the Artificial Airway 

movement, and that poses a number 
of problems. One is the difficult ques- 
tion of whether you pharmacologically 
restrain people, or whether you tie their 
heads down and restrain their tongues, 
which is obviously absurd. I've given 
up and accepted this as a part of life, 
but I think we could clean up our pro- 
tocol a bit since it's so commonly the 
case that the tube is affixed to the 
mouth in exactly the right place from 
the outside, and yet is moved inside 
by the patient's tongue movement. 
Typically, I'll get people to periodi- 
cally run a suction catheter down, drop 
the cuff, shove the tube in a little bit, 
and then pull it back until 1 can pal- 
pate the cuff below the cricoid in an 
adult, as a prophylactic measure. It 
used to be that we took daily chest 
x-rays and looked at where the tube 
was on the chest film. That, of course, 
became unaffordable. I'm curious to 
know what you do, or whether you 
just live with it and have people come 
and change the tube frequently and 
find out that the tube was really okay, 
but that the cuff was in the mouth or 
up in the larynx. 

Hess: Actually. I think it's very easy 
to determine whether there's a cuff 
rupture. All you need to do is use the 
set-up that I showed on the slide where 
you have the manometer and the sy- 
ringe attached to the cuff. If the sys- 
tem holds pressure even though there's 
a leak, it cannot be a cuff rupture. I 
think that's a simple thing that's often 
overlooked or is not done when there 
is a leak and somebody thinks that the 
problem is that the cuff is ruptured. 

Bishop: Dean. I think if the cuff 
comes back into the mouth, you actu- 
ally may have a change in pressure on 
your manometer, if you no longer have 
the tracheal wall restricting it. 

Hess: But. even if it's ruptured? 

Bishop: No, I'm saying that, in an 
unruptured cuff, you may see a de- 
cline in the pressure. In a chapter that 

Ray Ritz and I wrote for Dave Pier- 
son's respiratory therapy textbook' we 
laid out a protocol for dealing with 
the question of cuff rupture, and went 
through a variety of steps to handle a 
cuff that seems to leak. 


1. Bishop MJ. Ritz R. Airway managemenl. 
In: Pierson DJ. Kacmarek RM. editors. 
Foundations of respiratory care. New 
Yoric: Churchill Livingstone; 1992:82.^- 

Hess: If the tube has moved ceph- 
alad so that the cuff is inflated in the 
pharynx, that will result in a high cuff 
pressure, because it will require a high 
cuff volume. But that cuff will be able 
to hold pressure, so it should not act 
like a ruptured cuff. 

Bishop: Right. If it stays in one 
place, that's true. Jim (Reibel). maybe 
you can respond on this. One of my 
concerns has been seeing tubes with 
the cuffs too high, because I under- 
stand from my ear-nose-throat and tho- 
racic surgery colleagues that tracheal 
injuries are repairable, but subglottic 
injuries can be much more difficult to 
repair. A cuff inflated in the larynx 
can certainly cause damage. In rab- 
bits, inflating a cuff to exceed muco- 
sal perfusion pressure for one hour, 
we ended up with pretty significant 
laryngeal injury. So I worry about the 
cuff being too high and being just im- 
mediately subglottic. 

Reibel: You're correct. The cricoid 
is a complete circle. If you have an 
inflated tube up there, and the pres- 
sure if maintained, you're going to get 
problems. As you correctly point out, 
tracheal problems can be fixed, but 
laryngotracheal problems are much 
more difficult to fix. People have tried 
to adapt the anterior and posterior cri- 
coid split that they use in pediatric 
patients to adults. In my experience 
with very few of those, there is not a 
good extrapolation of pediatric expe- 
rience to the adult. Dr Grillo has a 

very interesting technique wherein he 
does a partial cricoid resection and de- 
velops a membranous tracheal flap. He 
does a circumferential subglottic ex- 
cision and then positions that mem- 
branous tracheal flap on the remain- 
der of the cricoid, protecting the 
cricoarytenoid joint. This technique 
has been successful in a great number 
of cases that otherwise would have 
been doomed to failure. This work has 
now been adopted and successfully re- 
produced at other institutions around 
the world. 

Bishop: I think the key point, 
though, is that in terms of prevention, 
people looking at chest films tend to 
be worried about the tube being down 
too far. but no one seems to be very 
worried about the cuff being too high 
up in the larynx. 

Hess: A technique that is sometimes 
described for determining proper tube 
placement is palpation of the cuff in 
the suprasternal notch. Would that im- 
ply that if you can palpate the cuff in 
the suprasternal notch that it may ac- 
tually be too high in the trachea? 

Heffner: High positioning is a con- 
cern, particularly considering that the 
cuff is going to move up and down in 
the airway with body position. Also, 
high tubes risk inadvertent extubation. 
The biggest concern is what Mike 
brought up — subglottic injury. That 
level of injury really shouldn't hap- 
pen from the cuff. It can happen from 
the tube going through the larynx. 
Dean. I think a source of confusion in 
monitoring cuff pressures is that some 
standard texts report pressures in cm 
HjO while others report it in mm Hg. 
It is difficult for caregivers to remem- 
ber how to convert from one to the 

Hess: Multiply mm Hg by 1.36. 

Heffner: Thank you. It seems that 
cuff pressure units should be standard- 
ized, because I've reviewed medical 


Respiratory Care • July 1999 Vol 44 No 7 

Managing the Artificial Airway 

records wherein from shift to shift dif- 
ferent therapists have measured with 
different devices in different units, and 
it really gets very confusing for the 

Hess: I think that happened to us 
when the therapists had the manome- 
ters that were in mm Hg and then we 
got them these fancy gadgets that were 
in cm HnO. 

Stauffer: Two questions. First, ex- 
actly how far should the tip of the 
endotracheal tube rest above the car- 
ina for a supine adult with head in 
neutral position in an intensive care 
unit? Second, when a cuff leak is 
present requiring inflation pressures of 
30-35 mm Hg or higher, what if any, 
are the indications for a foam cuff en- 
dotracheal tube placement? 

Hess: The chest radiology literature 
I saw while putting together this pa- 
per suggested that the tip of the endo- 
tracheal tube be 5 cm above the car- 
ina. As for the indications for the foam 
cuff, Charlie (Durbin) should address 
that question. To tell the truth, I've 
never known what to do with foam 
cuffs. There are times that we are asked 
to replace a trach tube with a foam 
cuff trach tube because the patient has 
a dilated trachea, and my experience 
with that is that it doesn't work very 
well, that the leak is just as great as it 
was with the conventional tube, and 
in fact you end up having to overpres- 
surize the foam cuff — essentially hav- 
ing to convert it to a conventional cuff 
in order to get a seal. So I have not 
been convinced that foam cuffs really 
add very much for the patient who has 
a cuff leak, particularly a cuff leak 
secondary to a tracheal dilation. 

Ritz: We don't use loads of them, 
but have found that if it is the first 
tube you put in, it works great. How- 
ever, if it is not the first tube used, the 
foam cuff does not seem to contribute 
much to solving cuff leak problems. 

Durbin: The foam cuffed tube is 
not a rescue device. It's designed to 
prevent tracheal damage. When used 
after tracheomalacia develops, just as 
with the Lantz tube, it may not form 
an adequate seal. Using either of these 
tubes after developing a dilated tra- 
chea does not make much sense. 

Watson: I disagree about the Lantz 
tube. It is possible to disarm the sys- 
tem, which I've done repeatedly in 
high pressure ventilating settings in 
the burn units and with bad ARDS. 
It's just a pain, and teaching every- 
body how to do it is very hard. 

Durbin: Well, you can overcome 
the protective pressure limitation with 
a Bivona cuff as well, but the point is 
it doesn't help the patient by doing 
that, and it costs more money than a 
conventional cuff. 

Campbell: You made a comment 
and showed a reference about closed 
circuit suction systems. And you al- 
luded that the cost effectiveness was 
improved versus the open technique. I 
think we're a little bit too quick to 
accept that, especially in light of the 
fact that they are maybe 1 times more 
expensive than an open suction cath- 
eter. In the majority of patients, the 
duration of mechanical ventilation is 
less than 24 hours. 

Hess: We costed that out in our 
medical ICU, looking at the distri- 
bution of mechanically ventilated 
days, and looking at the cost of 
changing the inline suction catheter 
once a day versus once a week, and 
changing the inline suction catheter 
once a week costs less to the insti- 
tution than doing open suction pro- 

Campbell: But doesn't that assume 
the patient is going to be ventilated 
for a week? 

Hess: No it doesn't. What we did 
was look at the distribution of me- 

chanically ventilated patients and 
costed it out based upon the fact that 
there were a percentage of patients 
ventilated for 1 day, 2 days, 3 days, 
and so forth. We took into consider- 
ation the distribution of ventilator 

Campbell: Bui the point still re- 
mains that if the patient is extubated 
in less than 24 hours, how could it be 
cheaper to apply a $10 device? 

Hess: Because we have other pa- 
tients who are ventilated for several 

Ritz: There's no price I can place 
on getting spit in the face. Inline suc- 
tion catheters prevent that from hap- 
pening so I don't care how much they 

Campbell: My point is that patient 
selection is probably warranted with 
that device — maybe not in your insti- 
tution, but in most institutions, I sus- 

Hess: I guess part of it, too, is how 
concerned you are about disconnect- 
ing patients from ventilators to suc- 
tion them. When you disconnect a pa- 
tient from a ventilator, you spray 
condensate and secretions out into the 
environment. You can attach a resus- 
citator bag to the airway to bag the 
patient during suctioning that may 
have a grossly contaminated valve or 
other kinds of issues that the closed 
suction system avoids. Closed versus 
open suctioning is clearly an emotional 
issue, including at our institution. 

Branson: You're talking about the 
medical ICU. I don't have that much 
experience in the medical ICU, but 
it's my experience from going up there 
that they don't have a lot of patients 
who are on for just a day. Do you 
have a lot of those patients, compared 
to the surgical ICU? 

Respiratory Care • July 1999 Vol 44 No 7 


Managing the Artificial Airway 

Hess: I can't tell you the exact num- 
ber, but it's more than 50%. 

Branson: Because what we see in 
the surgical ICU is that there's the 
group of patients who we would prob- 
ably use closed circuit suctioning on 
because we know they have bad ARDS 
and they're going to be on for a long 
time. And we have that other group of 
patients who we know are coming off 
today, and we wouldn't use it, and 
that would probably save money. 

Hess: Yes, but the problem with pa- 
tient selection is that it always works 
great in retrospect, but it never tells 
you what to do when the patient gets 
to the unit, at least not in my experi- 

Stoller: Dean. I think that, method- 
ologically, it comes down to what 
some would consider a sensitivity 

analysis. That is to say, if the distri- 
bution of duration of ventilation were 
to change radically toward a shorter 
duration of ventilation, there must be 
a cut point at which the cost-effec- 
tiveness no longer favors the inline 
suction catheter. And so the method- 
ologic question to address this discus- 
sion gets to that. Did you consider that? 

Hess: We did not do ROC curves. 

Stoller: Of course that would be the 

Hess: We don't use inline suction 
catheters in the post-anesthesia care 
unit, for example, nor in our cardiac 
surgery ICU, because those patients 
are extubated in hours. 

Hurford: We use them in the oper- 
ating room for thoracic operations on 
cystic fibrosis patients. It's the only 

way you can get enough suction cath- 
eters down there frequently enough to 
complete the case. 

Heffner: I was going to extend 
Jamie's (Stoller) point that 1 think we 
have to be careful with the use of "cost- 
effective" or "cost-effective analysis." 
We should only use that term if we've 
done a rigorous cost-effectiveness 
analysis that includes the societal per- 
spective of all the costs and all the 
benefits across the health care contin- 
uum. Really, what we're talking about 
is capital budget decisions in terms of 
what's cost-saving with a reasonable 
short-term benefit for the patient 
within the domain of the hospital, from 
the hospital's perspective. So that's 
really different than cost-effective 

Hess: That point is well taken. 


Respiratory Care • July 1999 Vol 44 No 7 

Prediction of a Difficult Intubation: Methods for Successful Intubation 

Charles B Watson MD 


Deflnition of a Difficult Airway 

Conventionally Trained Personnel 

Conventional Training — A Relative Concept 

Emergency Credentials 
Recognition of Difficult Intubation 
Incidence of Difficult Intubation 

Laryngeal Exposure 

Is the Setting or the Airway Difficult? 

Anatomic Problems 
Complicating Conditions 

Medical Conditions 
The Difficult Airway Algorithm 
Laryngoscopy Options 

Curved Laryngoscope Blade 

Straight Laryngoscope Blade 

Tube Laryngoscope 

Additional Maneuvers 


Staged Intubation 
Alternatives to Direct Laryngoscopy 

Blind Intubation 

Digital Intubation 

Magnetic Intubation 

Radiographic Intubation 

Blind, Stylet-Guided Intubation 

Confirming Blind Intubation 

Fiberoptic Systems 
Retrograde Techniques 

When to Discontinue Direct Laryngoscopy Attempts 
Intermediate Airways 

Evolution of the Esophageal Obturator Airway 

Pharyngeal-Tracheal Lumen and Cuffed Oropharyngeal Airways 

The Combitube 

The Laryngeal Mask Airway 
Failed Intubation and Failed Ventilation 

The Transtracheal Airway 

Approach to the Difficult Airway 

Practical AppUcation of a Difficult Airway Algorithm for Respiratory Care 

[Respir Care 1999:44(7):777-796] Key words: difficult intubation, difficult la- 
ryngoscopy, difficult airway, emergency intubation, staged intubation, airway 
screening, intubation, algorithm. 

Respiratory Care • July 1999 Vol 44 No 7 777 

Prediction of a Difficult Intubation 


Deflnition of a Difficult Airway 

Both translaryngeal and transtracheal intubation have 
long and interesting histories as medical procedures. They 
began as medical curiosities, performed by medical spe- 
cialists — rarely skilled — when infectious diseases of the 
upper airway like diphtheria and quinsy were commonly 
fatal. Now they are commonplace in the hands of acute 
care physicians, physicians' assistants, advanced practice 
registered nurses, and respiratory therapists. Despite in- 
creased use of noninvasive modes of ventilatory support 
and the recent introduction of newer, "intermediate" emer- 
gency airways, intubation of the trachea with a cuffed 
translaryngeal or transtracheal tube remains essential for 
continuous mechanical ventilation, effective secretion man- 
agement, and bypassing upper airway pathology. 

Since the promulgation of basic and advanced life sup- 
port (ALS) skills protocols over 30 years ago by the Amer- 
ican College of Cardiology, direct laryngoscopy for place- 
ment of a translaryngeal airway has become essential to 
acute respiratory practice. Numerous articles and chapters 
in basic respiratory and emergency texts have described 
the procedure.'"^ Intubation is widely taught in ALS, ad- 
vanced trauma life support, pediatric ALS, neonatal ALS, 
obstetric ALS, fundamentals of critical care support, para- 
medic, and emergency medical technician-intubation train- 
ing curricula. Hands-on experience is commonly gained 
in the operating room, where a number of individuals 
are electively intubated as part of routine surgical anes- 
thesia care. 

Mounting experience with difficult tracheal intubation 
in the anesthesia setting^-^ argues for a more methodical 
approach to individuals with anatomic and medical prob- 
lems that might complicate direct laryngoscopy.'" Conse- 
quently, the American Society of Anesthesiologists (ASA) 
published and updated clinical guidelines for dealing with 
patients who present a difficult airway and, in particular, 
an intubation challenge." Now modified guidelines from 
this source have been translated into other fields, including 
emergency medicine.'- It appears likely that difficult air- 
way management and difficult tracheal intubation will be- 
come routinely-promulgated ALS algorithms during the 
next decade'^ — a respiratory standard of care for acute 
care practitioners. 

Charles B Watson MD is affiliated with the Department of Anesthesia, 
Bridgeport Hospital, Bridgeport, Connecticut. 

Correspondence: Charles B Watson MD, Department of Anesthesia, 
Bridgeport Hospital. Bridgeport CT 06610-3801. E-mail: 
pcwats (3> 

The ASA task force" described the difficult airway as 
one that a "conventionally trained" anesthesiologist can 
not manage without systemic oxygen desaturation despite 
increased inspired oxygen tension and without signs of 
hypercapnia, including hypertension, tachycardia, and other 
secondary evidence of ventilatory inadequacy. Procedural 
expertise is defined by a trained individual who is rela- 
tively experienced with airway management and intuba- 
tion. The conventionally trained individual possesses av- 
erage skills for his or her specialty, which implies that he 
or she is not a regional expert. Regional experts from any 
specialty who participate in airway management are rarely 
available on a continuous basis in any institution. 

Conventionally Trained Personnel 

A conventionally trained anesthesiologist is recognized 
as proficient in direct laryngoscopy (DL), by virtue of 
having performed hundreds of tracheal intubations for op- 
erative anesthesia care. The experience is implicit in clin- 
ical training, although procedural numbers are not reported 
for certification by the American Board of Anesthesiolo- 
gists. Similarly, the Council on Accreditation of the Amer- 
ican Association of Nurse Anesthetists has no procedural 
guidelines for certification in DL. In our institution, a stu- 
dent nurse performs more than 1 50 DLs and demonstrates 
other proficiencies before he or she can join the code team 
that responds to ALS and intubation calls. In contrast, 
paramedics who train in our region perform supervised DL 
for operative intubation a handful of times prior to their 
certification and 6 times per year thereafter in order to 
maintain certification for field intubation procedures. Sim- 
ilarly, the average resident in the Yale/Bridgeport Hospital 
emergency medicine program performs 20-30 DLs as part 
of clinical training in the procedure. Contrast this with the 
basic experience for training in fiberoptic bronchoscopy 
suggested by the American College of Chest Physicians 
(50 procedures) and with the 40 transesophageal echocar- 
diography probe placements required for a cardiologist's 
certification in this procedure at the Mayo Clinic.''* 

Conventional Training — A Relative Concept 

Clearly, as with electrical cardioversion in the ALS set- 
ting, there must be a distinction between the expert and 
performance of the minimally-trained individual who re- 
trains periodically. The qualifications of technicians who 
perform tracheal intubation have been the subject of active 
debate. '5 Credentials for practitioners who work in the 
United States are controlled on a local level, either by state 
or regional requirements, as in the case of paramedics who 
work in regional ALS systems, or by a hospital's medical 


Respiratory Care • July 1999 Vol 44 No 7 

Prediction of a Difficult Intubation 

staff rules. Consequently, there is considerable variation in 
minimal requirements for the performance of tracheal in- 
tubation and other life-saving procedures, so "convention- 
al training" is a poorly defined concept. 

Emergency Credentials 

In our department, we distinguish between emergency 
procedures, which we would not frequently perform, and 
routine procedures that are performed on a day-to-day ba- 
sis. Someone with emergency credentials meets minimal 
training criteria and might perform the procedure only 
several times a year. Routine credentials, on the other 
hand, imply day-to-day practice of the procedure or skill in 
question. In effect, we have a two-tiered provider system 
for some emergency procedures at our institution. If there 
is time, we consult a conventionally trained specialist or a 
local expert. If there is not time, an individual with emer- 
gency credentials performs as best he or she can. 

Recognition of Diflicult Intubation 

As a practical matter, difficult intubation is recognized 
in one of 3 ways: first, as an obvious anatomic challenge; 
second, by association with complicating medical disease; 
and. third, after poor or failed visualization of the larynx 
and supraglottic structures during DL.'- Some anatomic 
and medical obstacles to DL are obvious, including severe 
mandibular hypoplasia, distorting neck masses, external 
surgical fixation of the head and neck or mandible, crip- 
pling cervical arthritis, cervical flexion deformities due to 
burn scars, trauma fixation devices, and disfiguring facial 
trauma. However, other less obvious systemic conditions 
and anatomic variations can also complicate laryngoscopy. 
Whether an effort to predict successful DL is justifiable 
has been argued. '^'^ Adverse effects of hypoxia injury, 
cardiovascular insult, or intubation trauma incurred during 
difficult or failed DL justify an airway assessment screen- 
ing history and physical exam for all but the most imme- 
diate emergency procedures.""*'^ The airway assessment 
items should include: ( 1 ) airway history, (2) record re- 
view, (3) examination of mouth, teeth, tongue, and neck, 
(4) submental distances, (5) neck mobility, (6) view from 
the side, (7) nasopharyngeal patency, and (8) systemic 

Incidence of Difficult Intubation 

The incidence of difficult DL and intubation is reported 
as 1.5-15%.'"-" -- Impossible intubation during anesthe- 
sia has been reported in fewer than 1% of patients stud- 
ied.'" Frequency data are complicated by the use of con- 
flicting terminology and clinical variation in risk scoring.-' 
Also, the incidence of difficult and impossible intubation 

Table I . Grades of Visualization on Direct Laryngoscopy 


Structures Visible on Direct 




• Supraglottic structures 

• Laryngeal inlet 

• Vocal cords 


• Epiglottis 

• Laryngeal inlet 

• Posterior aryepiglottic folds 


• Epiglottis only 


• Cannot see epiglottis 

(Adapted from Reference 24,) 

associated with anesthesia may be under-reported because 
clinicians often use alternative anesthetic techniques in 
order to avoid DL when they anticipate difficulty. 

Laryngeal Exposure 

The most widely accepted method of grading difficulty 
of DL is based on the quality of laryngeal view obtained.-'* 
Intubation following a grade 3 or 4 view, where the larynx 
is not visualized, must be considered blind. Table 1 shows 
the criteria for the grades of visualization in laryngoscopy. 
Both blind and difficult DL are more likely to be compli- 
cated by tissue trauma, failed attempts, esophageal intu- 
bation, cardiovascular and respiratory instability, and as- 
piration of gastric or pharyngeal contents.-'' 

Is the Setting or the Airway Difficult? 

While it stands to reason that DL in the emergency 
setting should be more stressful than in the operating room, 
most studies published from the emergency department, 
respiratory care, or pulmonary standpoint emphasize the 
success (rather than complications and difficulty) of DL 
for intubation in these settings. -''-'* Several research groups 
have compared intubation difficulty, outcome, and tech- 
niques employed in the field, emergency department, in- 
tensive care unit, and the operating room.''-'^ -''- First-time 
success rates are lower, while complication rates are high- 
er, ■^'"■* and a number of equipment and support personnel- 
related complaints are experienced in acute settings.-'*''' 
One rarely has time to obtain a complete history and per- 
form an optimal physical assessment. The incidence of 
active and passive gastrointestinal reflux is higher.'" 
Acutely decompensating patients in the special care units 
have a low margin of safety for hypoxemia, hypertension, 
hypotension, or other stresses.'"'^ These patients may re- 
quire intubation in suboptimal circumstances and loca- 
tions, and might be immobilized so that the intubator can- 

Respiratory Care • July 1999 Vol 44 No 7 


Prediction of a Difficult Intubation 

Table 2. Anatomic Causes and Mechanisms of Difficult Laryngoscopy 



Major Problem 

Disproportionate soft tissues 

Distorted anatomy 

Lingual hypertrophy 
Down syndrome 
Lingual tonsillar hypertrophy 
Marked obesity 
Supraglottic inflammation 
Prior neck dissection 
Expanding neck hematoma 

Peritonsillar abscess 

Pharyngeal mass and branchial cleft cyst 

Thyroid tumor/goiter 

Developmental craniofacial anomalies 

Spinal subluxation/osteophytes 

Maxillofacial trauma 

• Oversized tongue 

• Mass effect 

• Redundant soft tissue 

• Swelling 

• Torsion 

• Deviation 

• Obstructive edema 

• Lateral compression and risk 
of rupture 

• Deviated larynx/trachea 

• Bony incongruity and 
disproportionate anatomy 

• Extrinsic mass effect 

• Displacement and/or bleeding 

Inadequate jaw mobility 

Inadequate neck mobility 

Temporomandibular dysfunction 

Short mandibular ramus 


Malignant hyperthermia 

Myotonic crisis 

Neurolept-malignant syndrome 

Drug intoxication 


Degenerative cervical arthritis 

Morbid obesity 

Facial or neck bum scarring 



Cranial dysplasia 

Cervical meningomyelocele 

Cervical trauma 


Thoracic kyphosis 

Fixed or limited motion 
Inadequate hinge length 
Trismus and/or locked jaw 
Masseter tetanus and 
generalized rigidity 
Rigidity, trismus, tetanus 

Fused or irregular 
intervertebral joints 
Tissue limits movement 
Fusion and contractures 
Short, thick neck 
Limited neck extension 
Inadequate space 
External fixation 
Cervical extension limited 

not effectively extend and flex the neck for direct 
laryngoscopy. Clearly, the setting is a significant factor. 

Anatomic Problems 

DL for translaryngeal intubation requires displacement 
of the tongue and tissues at the floor of the mouth for 
alignment of pharyngeal and tracheal axes so that the lar- 
ynx can be seen.^** The body mechanics required for DL 
are adequate mouth opening, mobile soft tissues, a flexible 
neck, and a normally placed larynx. Numerous publica- 
tions document difficult laryngoscopy in patients with ab- 
normalities or variants in laryngeal position, soft tissue 
dimensions and mobility, jaw shape and function, neck 
flexibility, and cervical spine joint function.*'^-'*^ Predic- 

tive assessment for ease of DL and intubation begins with 
identification and recognition of typical settings. Table 2 
details the anatomic causes and mechanisms of difficult 
laryngoscopy, and Table 3 summarizes mechanical factors 
that predict difficult intubation. 

Interdental Distance. Prominent upper incisors can pose 
a problem because they limit laryngoscope blade place- 
ment that, together with marginal mandibular and lingual 
mobility, may render DL impossible. Unusual problems 
such as calcification of the stylo-hyoid ligament,"*'' can fix 
the base of the tongue so that it cannot be displaced for 
laryngoscopy. Jaw abnormalities such as mandibular coro- 
noid hyperplasia"* and cherubism,-*^ and temporomandib- 
ular joint (TMJ) disease can limit mouth opening. In ad- 


Respiratory Care • July 1999 Vol 44 No 7 

Prediction of a Difficult Intubation 

Table 3. Mechanical Factors that Predict Difficult Intubation 

Interdental space less than 6-7 cm 
Limited mouth opening (less than 6-7 cm) 
Limited temporomandibular joint mobility 
Disproportionate tongue 
Disproportionate mandibular ramus 
Disproportionate hypopharyngeal tissues 
Limited flexion of lower cervical spine 
Immobile CI -2 vertebral joint, limited flexion 
Short mandibulo-hyoid distance (less than 6-7 cm) 
Short mandibulo-thyroid distance (less than 6-7 cm) 
Short thyro-sternal distance (less than 6-7 cm) 
Anteriorly tilted or laterally deviated larynx 

dition, facial scarring due to traumatic bums or systemic 
disease (eg, pemphigus, epidermolysis bullosa, graft-vs- 
host disease) can restrict access to the oropharyngeal and 
nasopharyngeal airways, and limit neck extension. Inter- 
dental distances with mouth opening should average 4 cm 
in the adult and, with maximal effort, 6 cm or more. 

Temporomandibular Joint Function. The TMJ' s func- 
tions as both a gliding and hinge joint should be individ- 
ually tested, because each component can be significantly 
impaired and affect DL. In addition, one movement can be 
abnormal without affecting the other. The examiner places 
fingers over both TMJs and asks the patient to slide the 
jaw forward and then slide it from side to side. Palpable 
clicks, anterior dislocation, or grinding sensations, with or 
without pain, imply TMJ disease. Then the patient should 
be assessed for ability to open the mouth. Anterior dislo- 
cation may not be important — a significant percentage of 
the population can spontaneously dislocate and relocate 
the mandible anteriorly with a vigorous yawn. Indeed, 
easy dislocation may be helpful, because it can improve 
both the mask airway and laryngeal visualization during 
DL. Painful or significantly limited TMJ movement and a 
history of recurrent, long-lasting, painful TMJ dislocations 
are relative contraindications for orotracheal intubation. 
Patients with TMJ disease are often highly motivated to 
discuss intubation, because pain and limited movement 
interfere with their daily lives. The inflamed, arthritic, 
fused, or traumatized TMJ can markedly limit TMJ move- 
ment, even after muscle relaxants have been administered. 
Joint mobility, not muscle tone or masseter spasm, is the 

Intubation Difficulty Scores. There is an ongoing de- 
bate between the proponents of simple physical screens for 
intubation difficulty and those who argue on behalf of 
measured and derived indices of predictability. A number 
of radiographic studies have been performed that mea- 
sured bony distances as predictors of DL.^"" Dynamic 

Table 4. Modified Mallampati Visualization Scale 


Structures Visible on 
Oropharyngeal Exam 




Hard palate 

Soft palate 


Posterior pharynx 


Hard palate 

Soft palate 

Partial uvula and posterior 



Hard palate 

Soft palate 

No posterior pharynx 

Anterior tongue 
Hard palate 

Adapted from Samsoon GLT. Young JRB. Difficult tracheal intubation: a retrospective study. 
Anaesthesia 1987;42:487-190. 

radiographic studies have good predictive ability, but are 
not likely to be helpful in the clinical setting because of the 
cost and time involved.-*^ In 1985 Mallampati et al''- val- 
idated a predictive index of DL difficulty by visual inspec- 
tion and grading of tongue and pharyngeal proportions 
with maximal mouth opening. In 1987 Samsoon and Young 
modified Mallampati's 3-level descriptive scale by adding 
a fourth level (Table 4). Around the same time, Bellhouse 
and Dore'^ correlated measured jaw dimensions and cer- 
vical distances with anticipated ability to move the neck 
and displace the jaw and soft tissues for DL. Wilson et al-° 
measured several distances in 633 patients and derived a 
complex, 6-point "risk score" for DL, which they tested in 
778 patients. These variables predicted that 1.5% of pa- 
tients in Wilson's second group would be difficult to in- 
tubate; however, the predictive value of the tests, in ag- 
gregate, was only 75%. 

Multifactorial Intubation Difficulty Scores. Frerk et al 
combined the modified Mallampati scoring system with 
the measured distance between the anterior point of the 
jaw and the thyroid cartilage (thyromental distance) in a 
series of patients.-'''* They used radiographic correlation to 
show that thyromental distance correlates with the gap 
between the first and second cervical vertebrae and, pre- 
sumably, the ability to extend the neck at this joint. ""^ Patil 
et al also measured thyromental distances, and found that 
tracheal intubation is more difficult for patients with less 
than 6 cm space.-'"'' Recently, Randell reviewed studies of 
predictive indices and noted that the sensitivity of the Mal- 

Respiratory Care • July 1999 Vol 44 No 7 

Prediction of a Difficult Intubation 

lampati scale has been reported to be 42-81%, while that 
of the thyromental distance has been reported to be 62- 
91%, with a similarly wide range for specificity.-^'' Con- 
sequently, he argued that the best predictive system should 
involve multifactorial indices. However, a physician's po- 
sition on the measurement-versus-clinical-assessment de- 
bate may be more a matter of preference than measure- 
ment validity.''*' 

Observer Inconsistency. One of the confounding fac- 
tors that accounts for the wide range of predictive sensi- 
tivity reported for these tests is examiner variability. If the 
Mallampati screen is performed with the neck fully ex- 
tended, this exam combines neck mobility with an esti- 
mate of oropharyngeal space and tongue size, instead of 
estimating the oropharyngeal space and tongue dimensions 
alone. ""'' Additionally, when thyromental or hyomental mea- 
surements are performed with the neck extended, the cor- 
relation may differ considerably from measurement with 
the neck in neutral position. Indeed, some authors have 
argued that the poor sensitivity and specificity of intuba- 
tion screens, because of observer variability, invalidate 
predictive efforts altogether.''""' 

Mandibular Dimensions. Another problem with the pre- 
dictive sensitivity of both the measured indices reported 
and the descriptive scoring system is that jaw dimensions 
also play an essential role. Traditional predictive measure- 
ment has focused on tongue size, neck length, and neck 
mobility, with the thought that the larynx is commonly too 
■'high" or too "anterior" for adequate DL. Chou and Wu 
recently identified a group of patients with long necks, 
good Mallampati grades, and more than adequate thyro- 
mental distances, but who were difficult to intubate be- 
cause of relatively disproportionate mandibular dimen- 
sions."*^ They argue that tongue mobility is more a 
function of mandibulo-hyoid distance, since the hyoid bone 
plays a key role in lingual suspension, and that relative jaw 
opening is a function of the length of the mandibular 
ramus. "^ 

Laryngeal Tilt. Roberts raised the question of laryngeal 
inclination, and designed and promoted a laryngeal bubble 
inclinometer that, like a modified carpenter's level, mea- 
sures laryngeal angulation. ^ An anterior laryngeal tilt makes 
it harder for the laryngoscopist to see the laryngeal inlet. 
Cricoid pressure, applied to prevent gastrointestinal reflux 
and aspiration during intubation under sedation or paral- 
ysis, actually reduces the quality of visualization during 
DL by accentuating anterior laryngeal angulation. Recently, 
several groups have demonstrated that cricoid pressure 
administered simultaneously with cephalad and posterior 
pressure facilitates successful intubation of both pediatric 
and adult patients. Posterior pressure on the upper thyroid 

tends to correct the tilt caused by pressure on the cricoid, 
while rightward pressure directs the laryngeal inlet toward 
the laryngoscopist' s line of sight. This has been called 
optimal external laryngeal manipulation'' and backward, 
upward, rightward laryngeal pressure.''^ "'^ 

Value of Predictive Tests. A reasonable conclusion af- 
ter review of the airway literature is that predictive tests 
can be useful. Intubation screening test sensitivity may 
predict 75% or more of difficult DLs. However, the vari- 
ability in sensitivity and specificity reported does not jus- 
tify elaborate or costly screening tests. Most clinicians 
conduct a modified Mallampati exam, assess interdental 
space, comment on range of cervical motion, and perform 
a rough screen of jaw to hyoid, thyroid, and sternal dis- 
tances. Many combine several of these in one multifacto- 
rial screening maneuver. If the patient opens his or her 
mouth widely, protrudes the tongue, phonates, and simul- 
taneously extends the neck, one can get a general impres- 
sion of jaw mobility, oropharyngeal space, lingual size, 
and neck mobility. Another variant on this quick screen 
has been widely promulgated as the "Rule of Threes." If 
the examiner can place 3 fingers (approximately 6-7 cm) 
in the interdental space, between the anterior jaw and hy- 
oid bone, and between the thyroid cartilage and the sternal 
notch with the neck in neutral position, there is probably 
adequate "room" for DL. Significant difficulty with 2 or 
more of these components of the exam justifies a more 
detailed assessment, because the probability of difficult 
DL increases by 3-fold. Failed predictors indicate a need 
to plan an alternative airway management technique, 
whether as a primary approach or as a backup.''^ Time 
permitting, a more detailed assessment can direct the in- 
tubator to the most appropriate intubation technique when 
difficult DL is anticipated. 

Complicating Conditions 

Medical Conditions 

Table 5 lists congenital, developmental and, acquired 
systemic diseases that can complicate DL and intubation. 
Those that are associated with soft tissue and skeletal anom- 
alies have an obvious potential. Rheumatoid arthritis, for 
example, can present with laryngeal, cervical, TMJ, pul- 
monary, and other system involvement.'''*'''^ In general, 
patients with rheumatoid arthritis and ankylosing spondy- 
litis who have progressed to the stage of a fixed neck are 
quite difficult to intubate and have a high probability of 
TMJ involvement. By the time a patient with mul- 
tisystem disorders develops cervical rigidity, other airway 
components are involved as well.'"'-^' Patients with rheu- 
matoid and other degenerative arthritides can also develop 
cervical instability because of pathologic fractures, brittle 


Respiratory Care • July 1999 Vol 44 No 7 

Prediction of a Difficult Intubation 

Table 5. Congenital and Acquired Conditions Associated with Difficult Intubation 





Anderson's syndrome 
Angioneurotic edema 

Anhydrotic ectodermal 

Behfet's syndrome 
Cerebral gigantism 

Chubby puffer 

diseases and 


Cri-du-chat syndrome 

Crouzon"s disease 
Down syndrome 

Epidermolysis bullosa 
Erythema multiforme 
Fetal alcohol syndrome 

Glycogen storage 


Goldenhar's syndrome 
Goltz syndrome 

Hal lervorden-Spatz 

Histiocytosis X 

Hurler's syndrome 

Infantile gigantism 
Klippel-Feil syndrome 
Larsen's syndrome 

Leopard syndrome 

Meckel syndrome 
Median cleft face 

Miibius's syndrome 

Hypoplastic mandible, exophthalmos, craniosynostosis, retardation 
Growth hormone excess, overgrowth of bones, cartilage, and soft tissues 

with disproportion 
Mid-face hypoplasia, retrognathia, kyphoscoliosis, triangular facies 
Hereditary or acquired C 1 , C4 esterase deficiency. Episodic face and 

laryngeal edema 
Heat intolerance, abnormal mucous, hypoplastic mandible, respiratory 

Multiple contractures, congenital and progressive 
Ulceration airway, scarring, vasculitis 
Acromegalic features 

Fibrous dysplasia, mandibular abnormality 
Abnormal maxilla, cleft lip and palate, hepatosplenomegaly, skeletal 

abnormalities, atrial and ventricular septal defects 
Obesity, sleep apnea, cor pulmonale 
Bruising, hemorrhage, airway bleeding 
Multiple acquired and inherited autoimmune syndromes include: 

rheumatoid arthritis, polyarteritis nodosa, systemic lupus 

erythematosus, dermatomyositis 
Goiter, hypothyroidism, macroglossia, abnormal respiratory drive, 

Retardation, microcephaly, micrognathia, small larynx, cat-like cry in 

Craniosynostosis, hypoplastic mandible 
Macroglossia, small pharynx, retardation, hypotonia, associated 

Erosions and blisters, oral lesions, and tongue adhesion 
Urticaria, ulcerations, cardiac arrhythmias, coagulopathy, pleural blebs 
Multiple malformations, including microcephaly, microglossia, cardiac 

Muscle deposits of glycogen, weakness, macroglossia, cardiomegaly, 

and failure 
Unilateral or bilateral mass effect, deviated trachea/larynx, obstruction, 

retrosternal tracheal compression, vascular compression, supraglottic 

Unilateral maxillary and mandibular hypoplasia 
Multiple papillomatosis membranes and skin 
Craniofacial dysostosis, dental and eye abnormalities, skull asymmetry 

Basal ganglia disorder, dementia and dystonia with torticollis, trismus, 

and scoliosis 
Bone and visceral lesions, laryngeal fibrosis, coagulopathy and anemia, 

pulmonary and hepatic lesions 
Mucopolysaccharidosis, joint fusion, abnormal facies and gargoylism. 

deafness, dwarfism, and retardation 
Macrosomia, macroglossia, and exophthalmos 
Fused cervical vertebrae and neck rigidity 
Hydrocephalus, multiple dislocations, cleft palate and lip. abnormal 

laryngeal cartilages 
Freckles, 95% have pulmonic stenosis, growth retardation, pectus 

carinatum. kyphosis, genito-urinary anomalies 
Microcephaly, micrognathia, cleft epiglottis, renal dysplasia 
Multiple dysraphism. lipomas and dermoid tumors — especially over 

frontal bones 
Paralysis 6th and 7th cranial nerves, micrognathia, feeding difficulties 

Difficult intubation 
Airway and intubation 

Airway and intubation 

Airway obstruction and intubation 

Difficult intubation 


Scar contractures 

Airway and intubation 

Direct laryngoscopy quite difficult 

Airway and intubation 

Airway obstruction 

Obstruction, aspiration, mass effect 

Temporomandibular joint, 

cricoarytenoid arthritis, fixed neck 

Sensitivity to drugs, intubation, 

Difficult airway and intubation 

Intubation and direct laryngoscopy 
Airway and intubation 

Intubation and post-intubation lesions 
Airway and post-intubation 

Airway obstruction 

Obstruction, intubation 

Airway and intubation 
Airway papillomas 
Airway and intubation 

Airway and intubation, spastic 

Airway, bleeding, intubation 

Airway and intubation 

Large tongue, direct laryngoscopy 



Intubation and ventilation 


Intubation and laryngoscopy 

Aspiration and intubation 

Respiratory Care • July 1999 Vol 44 No 7 


Table 5 Continued 

Prediction of a Difficult Intubation 


Myositis ossificans 



Osteogenesis imperfecta 

Pierre-Robin syndrome 

Pyle's disease 

Rieger's syndrome 

Sleep apnea syndromes 

Superior sulcus tumor 

Superior vena cava 

Tangier syndrome 


Trisomy 13 

Turner's syndrome 

Vascular ring 


Zenker's diverticulum 

Bone changes, joint limitations, pulmonary disease, cardiac valve 

insufficiency, retardation 
Bony infiltration of tendons, muscle, fascia, and spine with cervical 

Progressive weakness, myotonic spasms, cardiac lesions, conduction 

abnormalities, respiratory failure, baldness, cataracts 
Cleft lip, palate, and tongue; hypoplastic maxilla and mandible; 

hydrocephalus; renal cysts; abnormal fingers 
Pathologic fractures, kyphoscoliosis, dental weakness, vascular fragility, 

Cleft palate, micrognathia, macroglossia, airway obstruction, and cor 

Craniofacial abnormalities, cranial neuropathy, and disproportionate 

Hypodontia, myotonia, and maxillary hypoplasia 

Large tonsils and adenoids, central respiratory unresponsiveness, 

redundant soft tissue, macroglossia, cranial nerve dysfunction, cor 

pulmonale, obesity 
Pain, thoracic outlet and arteriovenous obstruction, and recurrent nerve 

Vascular obstruction due to mass or clot causes upper airway edema and 

may obstruct trachea at subglottic level, compress heart 
Abnormal lipid metabolism, enlarged tonsils and adenoids, platelet 

dysfunction and hypersplenism, neuropathy, coronary disease 
Mandibulofacial dysostosis with micrognathia, aplastic zygomatic 

arches, choanal atresia 
Retardation, microcephaly, micrognathia, cleft lip and palate, ventricular 

septal defect, and dextrocardia 
Webbed neck, hypogonadism, micrognathia, renal anomalies, aortic and 

pulmonic anomalies 
Tracheal, vascular, and esophageal compression causes edema and 

Palatal and pharyngeal anomalies, congenital heart disease, vertical face, 

posterior mandible 
Acquired pharyngeal hernia or pouch 

Airway and intubation 

Intubation and airway 

Ventilation, arrhythmias, spastic 

Intubation and airway 

Immobile neck, intubation, loose 

teeth, bleeding 
Airway and intubation 

Intubation and airway obstruction 

Spastic contractures, airway 

Drug sensitivity, airway obstruction, 


Airway obstruction and intubation 

Airway obstruction, deviation, 

Airway obstruction, coagulopathy 

Airway obstruction, intubation 



Obstruction and difficult intubation 

Airway obstruction and intubation 


osseous structures, and multiple subluxations.^- When the 
neck is fixed or unstable, significant neurologic injury to 
the spinal cord is a possible complication of DL. Ad- 
vanced scleroderma is associated with failed esophageal 
contractility and soft tissue rigidity in the neck, as in other 
places. Neurofibromatosis can cause retropharyngeal le- 
sions that obstruct and distort the airway, ^^ similar to the 
irregular, protruding retropharyngeal osteophytes occasion- 
ally seen with degenerative osteoarthritis, ankylosing spon- 
dylitis, or idiopathic skeletal hyperostosis.'"-^'* Marked obe- 
sity is a condition that increases difficulty with both airway 
management and DL.''^ Obstructive and mixed central/ 
obstructive sleep apnea syndromes present a significant 
medical and surgical challenge, whether due to morbid 
obesity or to inherited disorders (eg, Prader-Willi syn- 
drome, ^■'' cranoisynostosis,^'' Marfan' s syndrome, ^^ acro- 
megaly,'"* Down syndrome,^'^ or Hecht syndrome**")- Al- 
though individuals with sleep apnea commonly have very 
poor airways and periodic breathing when they are ob- 

tunded or sedated, they may also be difficult to intubate 
because of anatomic problems that contribute to their ob- 
struction. Sleep apnea patients with a developmental syn- 
drome or multisystem disease (eg, acromegaly) may also 
be challenging. 

Neurologic Injuries. Localizing neurologic signs, de- 
creased consciousness, dilated pupil(s), posturing, and other 
evidence of increased intracranial pressure can present as 
a medical emergency with or without immediate airway 
compromise, as can sustained, uncontrolled seizures, or 
status epilepticus. Abnormal muscle activity with clenched 
teeth and stertorous or periodic breathing can make DL 
quite difficult, as well as raise intracranial pressure to 
more dangerous levels. Alternative techniques may be re- 
quired because anticonvulsant and sedative administration 
rarely decreases muscle activity enough to allow DL. As 
with intoxicated patients, such patients may require "phar- 
macologic restraint" to allow effective evaluation and 


Respiratory Care • July 1999 Vol 44 No 7 

Prediction of a Difficult Intubation 

care.*" The newer nondepolarizing muscle relaxants like 
rocuronium (Zemuron) and vecuronium (Norcuron) induce 
rapid paralysis for DL**- and intubation without causing 
muscle contracture, hypotension, tachycardia, or bradycar- 
dia. When used properly with sedatives and narcotics,^^ 
they allow effective ventilation, control of muscle metab- 
olism, and acute management of intracranial hypertension. 
A combination of anesthetic and relaxant agents titrated by 
an airway management expert will control cerebral metab- 
olism and blood flow, effectively eliminating secondary 
cerebral insults caused by straining, coughing, or hyper- 
tension. The implications of cervical spine fracture and/or 
dislocation are similar, except that flexion and extension dur- 
ing DL can induce or worsen spinal cord injury. For this 
reason, trauma airway paradigms include use of cervical fix- 
ation collars and manual in-line traction on the neck. 

Ophthalmologic Injuries. Patients with open ophthal- 
mologic injuries present unique problems. Straining, 
coughing, and intubation maneuvers can cause extrusion 
of vitreous or aqueous humor, as well as other delicate eye 
structures, that may be difficult to replace at surgery. Mus- 
cle contractions caused by succinylcholine paralysis can 
contribute to this process. The open eye, like multisystem 
trauma, requires advanced airway management skills and 
pharmacologic support. 

Coagulopathy and/or Anticoagulant Therapy. Spe- 
cial care in intubation must be taken with patients on an- 
ticoagulants and those with medical conditions that impair 
clotting function. These conditions increase the risk of 
airway bleeding and expanding airway hematoma during 
DL. A bloody field or the mass effect of an expanding 
hematoma may obstruct the laryngoscopist's view at DL, 
raise intracranial pressure, cause life-threatening airway 
obstruction,'"' and/or predispose to blood aspiration. Co- 
agulation problems may be self-evident because of ongo- 
ing bleeding, or they may be occult. In both situations, 
progressive bleeding after airway management maneuvers 
or DL can make subsequent attempts quite difficult. Typ- 
ically, the endoscopist begins with a stable situation that 
progressively deteriorates as intubation attempts or other 
traumatic airway maneuvers continue. Known or suspected 
coagulopathy requires a very cautious approach, including 
consideration of advanced, atraumatic techniques such as 
fiberoptic intubation. 

Chronic anticoagulant therapy is routine for patients with 
artificial heart valves or a history of significant deep ve- 
nous thrombosis, with or without pulmonary embolism. 
Platelet inhibitors and heparin are commonly used in res- 
cue therapy for acute or impending coronary or carotid 
occlusion and acute coronary interventions. Patients with 
impending peripheral vascular occlusion or recent vascu- 
lar surgery are often anticoagulated. Many patients under- 

going abdominal or orthopedic procedures and who are 
considered high risk for deep venous thrombosis received 
low dose heparin perioperatively. Newer, more homoge- 
nous heparin compounds and heparinoids that have a greater 
potency and are more consistently effective have been 
introduced recently in the United States and abroad. Oc- 
casionally, prophylactic drug regimens are associated with 
remarkably prolonged clotting times. 

Systemic conditions that impair the microvascular cir- 
culation can be associated with an evolving coagulopathy 
combined with the consumption of clotting factors and the 
release of endogenous circulating anti-coagulants. This is 
most common in sepsis, but overwhelming infection by 
the Rocky Mountain spotted fever bacillus or epidemic 
meningitis caused by the meningococcus are well known 
for inducing coagulopathy and platelet dysfunction. Also, 
severe pre-eclampsia and a variant condition known in 
obstetrics as the HELLP syndrome (hepatitis, elevated liver 
function tests, low platelets) are commonly associated with 
consumption of clotting factors, platelet dysfunction, and 
an increased risk of bleeding. Patients with severe hepa- 
titis, whether chronic or infectious, may present with sig- 
nificant clotting disorders due to impaired hepatic produc- 
tion of essential coagulation factors. Autoimmune diseases 
that are associated with dangerously low platelet levels 
and spontaneous or traumatic bleeding, like idiopathic 
thrombocytopenic purpura, can increase difficulty. Clini- 
cal signs such as subcutaneous bleeding, prolonged bleed- 
ing after needle punctures, and expanding tissue hemato- 
mas after trauma suggest active coagulopathy. Bleeding 
after minimal airway trauma can rapidly become a critical 
airway management problem. 

The Difficult Airway Algorithm 

A growing consensus of acute care practitioners identi- 
fied the difficult airway as a recurrent problem for life 
support and anesthesia. It has two presentations: unpre- 
dictably difficult intubation, and recognizably difficult in- 
tubation. Isolated efforts toward a goal-oriented approach 
led to disease-specific (eg, advanced trauma life support), 
regional, and organization-specific protocols. In the early 
1990s, an ASA task force took an evidence-based ap- 
proach to the issue by conducting a two-step meta-analy- 
sis — review of literature from 1 973 through 1 99 1 , and by 
drawing on the experience of 50 recognized airway man- 
agement experts." Decision pathways were based on crit- 
ical linkages between the views and data identified by the 
process. In brief, recommendations were: ( 1 ) preintubation 
assessment should be used as a guide for planning intu- 
bation, (2) awake techniques should be chosen if DL is 
likely to be difficult (Fig. 1), (3) alternative airways and 
techniques should be chosen in a methodical fashion when 
unexpected difficulty with DL is encountered (Fig. 2), and 

Respiratory Care • July 1999 Vol 44 No 7 


Prediction of a Difficult Intubation 

Awake intubation attempt 




■ Verify position 

■ Capnography 

• Oximetry 

• Clinical exam 

Consider alternative 

tracheostomy or 

Fig. 1. Awake Intubation Decision Algorithm. 

(4) an airway management algorithm will improve out- 
come. The ASA task force refrained from endorsing spe- 
cific techniques in various settings because the skills and 
options in each facility or system may vary somewhat. 
Subsequent experience led to the incorporation of newer 
"intermediate" airways (eg, the laryngeal mask airway) as 
potentially life-saving options when ventilation is difficult 
and DL for tracheal intubation is impossible. For instance, 
the laryngeal mask airway often achieves ventilation in 
nonintubatable patients, and can act as an intubation guide. 
It is recommended that equipment and supplies be or- 
ganized in a central location for dealing with difficult in- 
tubation procedures and that personnel be aware of insti- 
tutional protocols and related equipment. If the patient was 
initially difficult to intubate or ventilate, the extubation 
plan should take those problems into account. As with 
other advanced life support skills, DL and alternative tech- 
niques that are part of the difficult airway algorithm should 
be refreshed through retraining in simulation and practice. 

laryngoscope), reviewed briefly below. Since the prob- 
lems presented by the difficult DL vary, an example of 
each type should be available on the difficult airway cart. 
Most laryngoscopes are now available with fiberoptic light- 
ing systems that are more reliable and brighter. Battery 
bulbs that screw into the blade tend to become loose or 
corroded and flicker after repeated cleaning.' 

Curved Laryngoscope Blade 

The curved blade, exemplified by the Macintosh laryn- 
goscope blade, slides down the tongue and seats in the 
vallecula. It tends to provide greater mouth opening and 
affords a greater interdental aperture. It is thought to be 
easier for beginners and is most often the first choice for 
those with basic intubation skills. **■* The McCoy**''**'^ and 
Corazzelli modifications provide a flexible tip for the curved 
blade that lifts the base of the tongue and epiglottis further 
out of the endoscopist's view, facilitating intubation in 
some cases. 

Straight Laryngoscope Blade 

The straight blade, as exemplified by the widely-used 
Miller blade, gives a more complete view of the larynx as 
the operator lifts the epiglottis out of the way. The straight 
blade is more appropriate with anterior laryngeal angula- 
tion, limited interdental aperture, or limited neck mobili- 
ty. ^^ A helpful modification of the Miller blade places the 
light on the left side, so that it is less likely to be blocked 
by the tracheal tube as the tube is advanced through the 
field of view into the larynx. 

Tube Laryngoscope 

Laryngoscopy Options 

There are numerous variations on the 3 basic designs of 
laryngoscope blade (curved blade, straight blade, and tube 

Intubation attempt on patient under general anesthesia 





Ventilation inadequate 





■ Verify position 

■ Capnography 

Ventilation adequate 

• Awaken 

■ Call for help 

• Emergency 




Employ intermediate 

Fig. 2. Decision Algorithm with Anesthesia/Paralysis. 

The tube laryngoscope, as seen in half-round or 3-quarter- 
round configuration (eg, Flagg, Wis-Hipple, Wis-Foreg- 
ger) or in closed tube configuration (eg, Jackson or ante- 
rior commissure laryngoscope), is a straight blade with a 
curved shield that keeps soft tissue out of the field of view. 
The tube laryngoscope is most helpful in patients with 
prominent teeth, limited neck motion, or disproportionate 
soft tissues or tongue. 

Additional Maneuvers 

Additional maneuvers that improve the quality of the 
view during DL include optimal head and neck position- 
ing**'* and optimal external laryngeal pressure.*^ '■'*'* All de- 
scriptions of DL emphasize the need to optimally extend 
the upper cervical vertebrae while flexing the lower cer- 
vical spine. In most patients, the work of lifting and po- 
sitioning the head and neck can be reduced by placing a 
pillow under the occiput while extending the neck for 


Respiratory Care • July 1999 Vol 44 No 7 

Prediction of a Difficult Intubation 

laryngoscopy. Since the best maneuver for mask ventila- 
tion is marked extension of the neck, it may be helpful to 
use a small pillow or rolled sheets under the neck or shoul- 
ders for this purpose. These can be shifted from under the 
neck and shoulders, where the mask airway is optimal, to 
the occiput for the "sniffing" position and laryngoscopy, 
and back again for mask ventilation. A patient with a 
relatively large head or thin torso may have considerable 
anterior flexion of the lower cervical spine to begin with, 
and thus only require upper neck extension. Patients in 
cervical traction, or who have truncal obesity, may require 
forceful anterior lift during suspension laryngoscopy or 
laryngeal pressure. As noted earlier, cricoid pressure or an 
anteriorly tilted larynx displaces the laryngeal inlet ante- 
rior to the laryngoscope tip. Optimal external laryngeal 
pressure, together with adjusting head and neck position, 
may increase the quality of laryngeal view by one Cor- 
mack grade.^** Optimal external laryngeal manipulation 
should be considered if a first DL attempt is difficult. No 
single maneuver works for all patients, so the laryngosco- 
pist should seek the best view both by adjusting head and 
neck position and by recruiting an experienced person to 
provide optimal external laryngeal manipulation or sup- 
port the head and neck.**** If the patient is lying on the floor, 
it may be easier to manage intubation with the operator 
lying on his/her side rather than kneeling or squatting over 
the patient.^- 


Under emergency circumstances, one should always use 
a stylet, whether rigid, malleable, or flexible. Viewing the 
larynx clearly during DL is only the first step in tracheal 
intubation. Directing the tube through the mouth and lar- 
ynx and into the trachea may be almost as difficult. First- 
time success rates are higher when the tracheal tube is 
stiffened and can be directed more accurately. As the tra- 
cheal tube is passed through the laryngeal inlet, it may 
need to be rotated so that the anteriorly curved tip won't 
catch in the larynx. Forceful anterior pressure by a stylet- 
ted tube can traumatize the trachea. On the other hand, a 
flexible tube without a stylet may bend back into the phar- 
ynx and pass into the esophagus. By convention, the tra- 
cheal tube tip is beveled left to right so that the tip will not 
catch on the left vocal apparatus as it is passed into the 
larynx from the right side of the mouth. A stylet enables 
the operator to direct and rotate the tube so that this bevel 
turns anteriorly and slides into the trachea after it passes 
the level of the cords. A malleable stylet allows the intu- 
bator maximum flexibility of shape to achieve the ideal 
curve and angle for oral intubation. A flexible stylet such 
as the FlexGuide (Mallinckrodt Inc, Pleasanton, Califor- 
nia) can be redirected in use so that the tip of the tube can 

be passed into and below the larynx without withdrawing 
and reshaping the stylet. 

Staged Intubation 

Staged intubation has been widely used in the United 
States and abroad for difficult intubations or when the 
view of the larynx is imperfect. Staged intubation tech- 
niques employ a guide wire, gum rubber elastic bougie, 
controlled stylet, or angled ventilating stylet. With this 
approach, a stylet is passed into the larynx and trachea as 
the first stage, either under direct vision or blindly. In the 
second stage, the stylet provides the guide over which an 
endotracheal tube is passed through the larynx.**'^ '^' The 
gum rubber bougie is a common surgical item, found in 
many operating rooms, and has been most widely used as 
an intubation guide in this setting. A modified tracheal 
tube that facilitates staged intubation has been introduced 
in the United Kingdom,'^- but is not yet available in the 
United States. A translaryngeal guide wire can be used as 
the first of 3 steps for passage of a tapered stylet or a 
hollow ventilating stylet over which intubation can be 
achieved. Insufflating or ventilating stylets allow oxygen 
tlow, jet ventilation,^' or assisted breaths as an endotra- 
cheal tube is advanced over them through the larynx and 
into the trachea.'"''^ In cases where the patient is breathing 
spontaneously and DL is difficult or impossible, accuracy 
of blind intubation over an insufflating stylet can be en- 
hanced. The Airway Exchange Catheter (Cook Interna- 
tional Inc, Bloomington, Indiana) is a 2-ended, hollow 
stylette with side air holes and depth markings. It is avail- 
able with 2 types of ventilating adapters. One is a Luer 
lock fitting for insufflation and the other is a 15 mm adapter 
for bag ventilation. Each is easily detached .so that insuf- 
flation can be interrupted for passage of a tracheal tube. 
This useful device comes in pediatric and adult sizes, with 
both straight and angled versions, for intubation and as a 
guide for tracheal tube change. Sonic devices that amplify 
breath sounds'*^ or capnometers'" '''* that confirm phasic 
carbon dioxide exhalation through an insufflation stylet 
add a measure of security to staged procedures. 

Alternatives to Direct Laryngoscopy 

Blind Intubation 

Blind intubation can be performed both nasally and 
orally. Many blind intubations are performed during at- 
tempted DL when the view is inadequate. The tracheal 
tube or an intubating stylet is blindly directed toward the 
operator's best guess of laryngeal location. Note that in the 
trauma setting, there is a significant risk of foreign body 
dislocation from the damaged airway and into the trachea 
as the endotracheal tube is passed." 

Respiratory Care • July 1999 Vol 44 No 7 


Prediction of a Difficult Intubation 

One disadvantage of blind intubation is that even sev- 
eral confirmatory tests do not absolutely assure that the 
tracheal tube is correctly seated below the glottic aperture 
(and not within the glottic aperture). '*'* Various types of 
tube benders and guides'"" have also been used to facili- 
tate blind techniques.'"' 

The nasal approach, while complicated by an increased 
risk of bleeding, nasal bone fracture, and sinusitis.'"- has 
been widely utilized over the years for blind intubation. 
This is partly because a tube that makes the nasopharyn- 
geal curve into the posterior pharynx is angled so that it is 
more likely to pass anteriorly into the larynx than an oral 
tube. Several techniques can enhance success of blind na- 
sotracheal intubation; these include head and neck reposi- 
tioning, inflation of the tracheal tube cuff,'""* use of a tube 
(eg, the Endotrol tube [Mallinckrodt Inc, Pleasanton, Cal- 
ifornia]) or stylet that can be directed into line with the 
larynx, and passage over a nasotracheal suction catheter. 

Digital Intubation 

Digital intubation, in which the tracheal tube is guided 
manually into the larynx, is most useful in a resuscitation 
setting, with a flaccid patient, when intubation equipment 
is faulty, or when large quantities of vomitus or blood 
obscure the airway. One of the operator's hands is inserted 
deeply into the mouth so that one or two middle fingers lift 
the epiglottis as others palpate the posterior larynx. The 
tracheal tube is advanced between these guiding fingers 
into the larynx with the other hand. Obviously one must be 
able to open the mouth and have a hand that fits in the 
mouth. Blind digital intubation is easier if the patient is 
edentulous and the operator has long, slender fingers. 

Magnetic Intubation 

Another variant of the staged intubation technique 
employs a magnetic stylet that is directed by a powerful 
magnet over the larynx or the sternal notch.'""* Blind place- 
ment can be confirmed using any of the methods described 

Radiographic Intubation 

There are some case reports of difficult airway intuba- 
tion conducted under fluoroscopic guidance in an elective 
situation.'"'' Computed tomography has been used at least 
once,'"'' and it seems likely that magnetic resonance im- 
aging will be put to this use as well. 

Blind, Stylet-Guided Intubation 

A curved stylet, rigid or malleable, can be employed as 
a guide for blind orotracheal intubation. This is usually a 

2-handed technique. A stylet carrying an endotracheal tube 
is directed by one hand while the other hand palpates the 
neck as the stylet is directed behind the tongue toward the 
larynx. The sensing hand determines whether the tube and 
stylet successfully enter the larynx. Most clinicians don't 
use this technique in day-to-day practice because of the 
risk of blind trauma to the oropharynx and airway. How- 
ever, an expert can use this technique without complica- 
tions in most patients with normal upper airways. 

Confirming Blind Intubation 

Spontaneous ventilation through the tube may be evi- 
dent upon direct inspection'"^ or auscultation of amplified 
breath sounds. After blind intubation, whether ventilation 
is spontaneous or controlled, confirmatory techniques like 
capnometry''**'"** and physical examination are needed, be- 
cause the tracheal tube was not visualized as it passed into 
the trachea.'"'^"" One effective technique for confirming 
intubation involves bulb reinflation.'" Since the esopha- 
gus does not contain air, neither a (non-self-inflating) ven- 
tilating bag nor a large rubber bulb will inflate if the tube 
is in the esophagus. "- 

Fiberoptic Systems 

Other modifications of the staged technique are helpful 
as alternatives to DL when difficulty is anticipated. Rigid, 
malleable, and flexible fiberoptic systems are widely used. 

Flexible Systems. Several models of flexible fiberoptic 
bronchoscope (FFB) are used for a number of airway in- 
terventions in critical care and anesthesia practice."-'"*' 
In most cases, the FFB functions as a visually guided stylet 
over which the endotracheal tube is passed."^"" Most 
fiberoptic approaches are. therefore, not blind tech- 
niques.'^''"'' The experienced operator can guide a FFB 
through the nose or mouth and into the trachea in one pass. 
Alternatively, the FFB can be passed through an intubating 
guide or an intermediate airway that serves as a guide, 
such as the laryngeal mask or the pharyngeal-tracheal lu- 
men airway (discussed below)."-* When the FFB cannot 
be pas.sed directly into the airway as an intubation guide, 
it may serve to direct a guide wire or other stylet, over 
which staged intubation can be performed. ' ''* Alternatively, 
an FFB can serve as an indirect laryngoscope that provides 
guidance for a stylet or tube passed from the side.'-" Short, 
flexible instruments designed for indirect laryngo.scopy 
have also been popular for nasal and oral intubation: how- 
ever, the operator has no ability to evaluate the lower 
airways or perform endobronchial intubation with these 
systems. Other FFBs, such as the choledochoscope and 
cystoscope, have also been used for fiberoptic intubation. 


Respiratory Care • July 1999 Vol 44 No 7 

Prediction of a Difficult Intubation 

Alternative Fiberoptic Instruments. Rigid and mallea- 
ble fiberoptic systems are used as intubation guides and 
for indirect laryngoscopy. Straight, rigid instruments mod- 
eled on the Hopkins telescope are used for direct laryngo- 
scopic examination and as intubating stylets. The mallea- 
ble fiberoptic system is more versatile. It can be shaped for 
the airway and inserted orally, either directly or with other 
I adjuvants such as a direct laryngoscope or tongue depres- 
j sor. Malleable systems come in 2 types. The earliest was 
I an intubating laryngoscope-stylet that carries an endotra- 
; cheal tube over it (American Optical and other manufac- 
turers). More recently, a malleable video stylet has been 
developed that can be placed into the trachea, orally or 
nasally, as the first step in staged intubation. Another in- 
novative variant on this idea is the fiberoptic endotracheal 
tube, which can be used as an indirect fiberoptic laryngo- 
scope for intubation and for periodic assessment of the 
trachea and tube position afterwards. 

The Bullard, Wu, and Upshur Scopes. The Bullard 
laryngoscope (Circon Corporation, Santa Barbara, Califor- 
nia) is a rigid fiberoptic blade with an external light source 
that carries an angled stylet. Minimal mouth opening is 
required for a laryngeal view, so this device can be used 
when neck and jaw mobility are inadequate.*""-' Using 
this system, the larynx is kept under direct vision while a 
tracheal tube is passed from the side. A single- or double- 
lumen endotracheal tube can be passed over the laryngo- 
scope's integral stylet and into the larynx under direct 
vision. The WuScope (Achi Corporation, Fremont, Cali- 
fornia) is a tube laryngoscope that incorporates an FFB as 
its guide. It must be passed through the mouth, but it 
provides an excellent view of the larynx through a narrow 
aperture and allows intubation with either a single- or 
double-lumen endotracheal tube over a stylet. Neither the 
Bullard scope nor the WuScope require as much jaw mo- 
bility or neck flexion and extension as do conventional 
DL. The Upshur scope (Meditron, Keighley, United King- 
dom) is another fiberoptic variant, and has advocates, 
though some feel that it is more cumbersome than con- 
ventional laryngoscopy.'-- None of these instruments al- 
lows a view of the trachea very far below the larynx. 

Video Laryngoscopy. Most fiberoptic systems can be 
connected to a video monitor so that more than one clini- 
cian can observe the pathology so as to allow video re- 
cording of the procedure.'-" An additional advantage is 
removal of the operator' s eye from the potential path of 
oral secretions or vomitus. 

Light Wand Intubation. Blind, light-wand intubation 
employs a fiberoptic stylet that is guided into the larynx 
by way of external determination of the stylet's location 

Respiratory Care • July 1999 Vol 44 No 7 

in the neck, based on transillumination through the 
neck. '23-1 26 Proponents of the light wand argue that it is as 
effective as DL, but less traumatic. '^^ The Augustine Guide 
(Augustine Medical Inc, Eden Prairie, Minnesota) pro- 
vides a manipulator and lighted stylet for blind intuba- 
tion. '"-'29 From time to time the FFB has been used as a 
fiberoptic light wand. 

Fiberoptic Systems: Summary. Fiberoptic devices pro- 
vide a number of options for laryngoscopy and intubation. 
Full length instruments such as the FFB can be used through 
the mouth, nose, or tracheostomy, and they allow the op- 
erator to see around corners and obstacles in the airway. "'^ 
The FFB offers versatility, because it can be used for 
bronchial work, including tracheostomy,'''" as well as in 
the upper airway. Fiberoptic techniques are highly suc- 
cessful and less traumatic in a number of difficult intuba- 
tion settings,*^ but they require time '-3' and special exper- 
tise that may not be available in the acute setting. ''"■^'^■"^ 
Since they are not always successful, other options must 
be available.''-3'33.'34 

Retrograde Techniques 

Retrograde intubation employs a transtracheally directed 
guide wire or catheter that is passed into the pharynx from 
the cricothyroid membrane. The retrograde wire will sup- 
port a stylet or FFB that ultimately guides a translaryngeal 
tube into place. The retrograde technique has been useful 
for difficult pediatric and adult airways. It is an old ap- 
proach that has seen increased popularity since the 
introduction of a new kit that includes a tapered stylet 
for passage over an atraumatic guide wire for use as an 
intubation guide (Cook Critical Care Inc, Bloomington, 

When to Discontinue Direct Laryngoscopy Attempts 

As noted previously, the ASA task force supported a 
systematic, protocol-driven approach to the difficult air- 
way. '^ Representatives of other medical specialties, in- 
cluding trauma surgeons and emergency medicine practi- 
tioners, '" have implemented algorithms for difficult airway 
management as well. Key elements of these protocols in- 
clude recognition of problems that would preclude intu- 
bation by rigid laryngoscopy and recognition of difficulty 
when direct laryngoscopy fails. When intubation difficulty 
is predicted, alternative equipment and individuals with 
special skills can be assembled prior to attempting DL. 
When difficult DL is encountered unexpectedly, direct in- 
tubation attempts should be limited to 2 or 3 at most, and 
the duration of intubation attempts should be limited as 
well. After the first failed attempt, pause to rethink the 


Prediction of a Difficult Intubation 

situation, reconsider patient and operator positioning, and 
possibly choose an alternative blade. The most skilled in- 
dividual available should attempt the DL. Consider alter- 
native methods if the second DL attempt fails. Early aban- 
donment of DL and use of intermediate airways for rescue 
ventilation, together with alternative intubation techniques, 
may be lifesaving. Difficult airway algorithms emphasize 
the prompt use of alternatives, which may include a sur- 
gical airway or percutaneous transtracheal airway, to avoid 
the possible adverse effects of interrupted ventilation or 
laryngoscopic airway trauma. Appropriate equipment for 
management of the difficult airway must be available. Since 
advance recognition of the problem is not guaranteed and 
the setting may be life-threatening, difficult airway man- 
agement supplies must be available to all of the acute care 
areas of a hospital and the emergency department. 3' 

Intermediate Airways 

Evolution of the Esophageal Obturator Airway 

Artificial airways other than the endotracheal tube were 
once limited to oropharyngeal and nasopharyngeal airways 
employed with conventional ventilating bag/valve/mask 
systems. Cuffed endotracheal tubes inadvertently placed in 
the esophagus during blind or failed intubation attempts 
have been used to vent esophageal contents during mask 
ventilation. In effect, a misplaced tracheal tube can serve 
as an esophageal obturator. An esophageally-placed tube 
commonly diverts gastrointestinal contents from the phar- 
ynx, and its balloon, when inflated, blocks refluxed con- 
tents from the lower airway. This principle was adapted to 
rescue airways. A blunt double-lumen esophageal obtura- 
tor blocks the esophagus and provides an oropharyngeal 
airway that mates with a mask or standard 15 mm tracheal 
tube connector. The more sophisticated, esophagogastric 
tracheal obturator (EGTO) system employed a hollow dis- 
tal obturator tube. It was also used with a specially de- 
signed mask for ventilation. Because the EGTO's distal 
tube might blindly pass orally into the larynx during in- 
sertion, it was designed to allow tracheal ventilation, if 
translaryngeal intubation were recognized. The esophageal 
obturator concept works in the acute setting, although the 
esophageal obturator airway and EGTO are inferior to 
translaryngeal intubation. For this reason, they have largely 
been abandoned by hospitals and emergency medical ser- 
vices in the United States. '^''■''^ 

by Benumof as supraglottic airways, because they all ter- 
minate in the pharynx and use a ventilating pathway that 
includes the larynx.^ The pharyngeal-tracheal lumen air- 
way (PTL) (Mallinckrodt Inc, Pleasanton, California) and 
the cuffed oropharyngeal airway (COPA) (Mallinckrodt 
Inc, Pleasanton, California) displace pharyngeal tissues 
with a pharyngeal balloon to facilitate ventilation. De- 
scriptions of use of the PTL have been published for field 
resuscitation and emergency department applications.'^* 
The PTL has a unique role when upper airway bleeding 
obstructs the intubator's view of the larynx."** The COPA, 
a modified oropharyngeal airway with a low pharyngeal 
balloon, must be sized appropriately and has been more 
widely used in the anesthesia setting.''*'^ Like the PTL, 
the COPA has a 15 mm ventilating adapter so that a bag/ 
valve system can be directly attached for ventilation. In 
addition, the COPA can be used as a route for tracheal 
intubation. ''♦"The appropriate COPA tends to be a size 
larger than the comparable Guedel oropharyngeal air- 
way that would ordinarily be employed with mask venti- 
lation. Just as an inappropriately placed oral airway can 
obstruct by forcing the epiglottis and/or base of the tongue 
into the lower pharynx, an oversized COPA can seal the 

The Combitube 

The esophago-tracheal Combitube (Kendall Healthcare, 
Mansfield, Massachusetts) was designed by Dr Frass et al 
as an improved esophageal obturator airway. '^^ It is a 
double tube with upper oropharyngeal and esophageal bal- 
loons. It functions like an EGTO but has a ventilating 
adapter for the pharyngeal airway tube, and a pharyngeal 
balloon. The Combitube replaces the confusing mask con- 
nection of the EGTO with a standard ventilating adapter, 
and opens the pharyngeal airway with its oropharyngeal 
balloon. If a Combitube is passed too far into the airway, 
the pharyngeal balloon can obstruct the glottis. '''■' It has 
been used in the field,'-'- in critical care settings for long- 
term ventilatory support,''*^ and as an intermediary for 
FEB intubation and tracheostomy.'**'-*-'' There is some ev- 
idence that the Combitube is easier for emergency medical 
technicians to place and use in the field than the PTL, the 
oral airway and bag/valve/mask system, or the laryngeal 
mask airway (LMA).'** 

Pharyngeal-Tracheal Lumen and Cuffed 
Oropharyngeal Airways 

Recently, other airways have been introduced in anes- 
thesia practice and field resuscitation. These are described 

The Laryngeal Mask Airway 

The LMA is used as a primary airway during anesthesia 
when esophageal reflux is not a potential problem and 
high ventilatory pressures are not required. The LMA was 


Respiratory Care • July 1999 Vol 44 No 7 

Prediction of a Difficult Intubation 

invented about 20 years ago by Dr Archibald Brain. It is 
awkward looking, but effectively bypasses the upper air- 
way and places a ventilating mask around the larynx, using 
a special cuff design that, because of its unique shape, 
seats in the hypopharynx. A grid over the distal end of the 
ventilating tube prevents soft tissue or the epiglottis from 
protruding into the airway and obstructing it. The LMA 
comes in 7 sizes, one for each age range. No matter how 
the LMA is sized, the pharyngeal cuff can only provide a 
low-pressure seal. If the LMA is sized properly, peak air- 
way pressures required for a leak should be 20-25 cm 
HjO. Since cuff inflation increases the posterior pharyn- 
geal space, it prevents supraglottic soft tissue obstruction 
unless the cuff itself is inflated over the pharynx, which 
rarely occurs.''*'' There is evidence that during clinical an- 
esthesia the LMA is more reliable than the COPA.'""* More 
recently, it was recognized by anesthesia personnel as a 
rescue airway through which tracheal intubation can be 
performed when mask ventilation is difficult and direct 
laryngoscopy is unsuccessful.'''''*'"''^'' Fiberoptic technique 
increases the success rate of intubation through an LMA 
for adults and children,''''''55-i57 and retrograde technique 
has been employed as well.'°' Lately, it has been sug- 
gested as a primary airway for resuscitation."* One short- 
coming of the LMA as a bridge to tracheal intubation is 
the length and diameter of the insertion tube. A tracheal 
tube larger than 6 mm internal diameter cannot pass through 
the conventional LMA. In addition, since smaller tracheal 
tubes are also shorter in length, a 6 mm tracheal tube is 
more likely to have its cuff inflated within the larynx of 
taller patients. A number of techniques have been designed 
for staged tube change for a size that is more convenient 
for long-term ventilatory support. 

A newer modification of the LMA, the intubating LMA 
(iLMA) has been specifically designed for blind tracheal 
intubation."'* The iLMA functions as an airway in the 
same fashion as the LMA. A shorter, wider ventilating 
tube makes it easy to pass or withdraw an iLMA from over 
a translaryngeal tube. A redesigned, tapered tracheal tube 
is passed blindly through the vendlating airway. The oro- 
tracheal tube can be as large as 8 mm. Consequently, it is 
not necessary to change the tracheal tube from a 6 mm to 
a larger size for adults after intubation, as with a conven- 
tional LMA. The iLMA has a flat metal handle that projects 
posteriorly. This allows the intubator to stand above the 
head of a supine patient and reposition the iLMA for blind 
attempts to pass the tracheal tube. Early field trials indi- 
cated that the iLMA design increases the success of blind 
intubation to 90-100% for patients without laryngeal 
pathology (compared to from 20-40% with the 
LMA).'""-""* The iLMA can be used for both staged 
intubation and extubation. 

Failed Intubation and Failed Ventilation 

The Transtracheal Airway 

When alternative intubation techniques and intermedi- 
ate airways are inappropriate or fail, the transtracheal air- 
way is the definitive option.'' " Transtracheal airway op- 
dons include transtracheal jet catheter, percutaneous 
cricothyrotomy and tracheotomy kits, and surgical crico- 
thyrotomy or tracheotomy. Cardiopulmonary bypass has 
been used from time to dme"''* but is limited in availability 
and most commonly reserved as a standby option in the 
operadng room. In recent years, a broad range of percu- 
taneous transtracheal airway kits has come on the mar- 
l^^gf 166,167 Percutaneous needle-catheter systems are easily 
inserted when the trachea can be palpated and allow ox- 
ygen insufflation and jet ventilation.-^ They may also fa- 
cilitate translaryngeal intubation. "'** Most percutaneous sys- 
tems utilize a modified Seldinger technique, derived from 
methods used to place percutaneous vascular catheters. A 
guide wire passed through a needle or catheter, followed 
by a dilator, allows passage of large-diameter catheters or 
tracheal tubes into the trachea. Surgical cricothyrotomy or 
tracheotomy has an important place in the difficult airway 
algorithm. A surgical airway may be an initial option in 
the patient with anticipated difficulty, or a choice when the 
airway is lost and no other approach will produce rapid 
results. Clinicians who use the Seldinger technique in day- 
to-day pracdce are more comfortable with its applications, 
while surgery-trained individuals with up-to-date skills may 
produce faster results with direct tracheotomy or cricothy- 
rotomy. Both surgical and percutaneous techniques are 
problemadc when the neck is fixed or scarred in flexion or 
when masses distort the anatomy. 

Approach to the Difficult Airway 

Many Alternatives. The list of choices for difficult air- 
way management is long. Institutions that have attempted 
to provide equipment and technical support for most of 
these options incur logistical difficulty with equipment 
provision and replacement, staff readiness, and the delin- 
eation of systematic approaches. When almost every op- 
tion is present at a difficult airway station or on a desig- 
nated cart, pracdtioners have difficulty finding the 
equipment needed for a particular approach. The cost of 
equipping each potential location with a multitude of in- 
tubation equipment items could easily exceed the cost of 
setting up a standard ALS cart, including defibrillator. 
Teaching personnel and maintaining their expertise with 
numerous intermediate and surgical airway options present 
a daundng challenge to insdtutional or departmental edu- 
cation programs. Increasing complexity presents increased 
risk of error, confusion, and failure. 

Respiratory Care • July 1999 Vol 44 No 7 

79 i 

Prediction of a Difficult Intubation 

Table 6. Difficult Airway Cart Equipment and Supplies 

• Routine intubation kit with blades, airways, tubes, oxygen source, 
suction and bag/valve/mask system 

Flagg, Foregger, Wisconsin or other tube laryngoscope blades 
Malleable intubating stylets 
Angled insufflating stylets 
Tube changers in 3 sizes 

Magill forceps for directing nasotracheal intubation 
Intubating laryngeal mask airway kit (multiple sizes with special 
tracheal tubes) 

Retrograde tracheal intubation kit (adult and pediatric) 
8 French rapid infusion device/percutaneous cricothyrotomy kit 
High pressure oxygen insufflation system with manual trigger 
Fiberoptic intubation airways 
Malleable fiberoptic stylette laryngoscope 

Flexible intubating fiberoptic bronchoscope with battery light source 
Surgical tracheotomy kit 
Percutaneous dilatational tracheotomy kit 
Portable chemical or infrared capnometer 
Portable pulse oximeter 

Keep It Simple. Experience with ALS and other tech- 
nical medical systems corroborates the idea that practitio- 
ners should employ techniques they are familiar with — 
"keep it simple." These observations, together with 
considerable regional variation in personnel availability, 
financial resources, and technical expertise, argue for the 
creation of institution-specific or region-specific protocols 
for management of the difficult airway.'-'^ Surgical op- 
tions will, of course, be less comfortable for nonsurgical 
respiratory therapists, while surgeons and others who prac- 
tice in high-volume trauma centers with ample surgical 
back-up may wish to promote surgical airway interven- 
tions to their first option when translaryngeal intubation 
fails or is impossible. It is probably best to limit the equip- 
ment options in order to reduce maintenance and training 
requirements. Table 6 lists the equipment in a more re- 
stricted difficult airway cart. 

Practical Application of a Diillcult Airway Algorithm 
for Respiratory Care 

The difficult airway algorithm fits into a continuum of 
airway management in acute respiratory care. In each in- 
stitution, equipment, airway management protocols, and 
training should be well defined. Patients who are obtunded 
or unconscious should be approached "awake." An alter- 
native approach is necessary when the experienced respi- 
ratory therapist or first-tier responder is unable to intubate 
the patient after 2 attempts, using a logical sequence of 
intubation maneuvers including repositioning the head and 
neck and backward, upward, rightward laryngeal pressure. 
If ventilation can be managed, effort can be directed to- 
ward finding a more experienced individual. During this 

time, alternative equipment and drugs can be accessed. 
When ventilation is inadequate, another option must be 
selected. Consideration should be given to rescue airway 
insertion as a temporizing measure. Definitive transtra- 
cheal intubation is an appropriate choice. Although very 
active patients may require pharmacologic restraint with 
paralytic drugs, these should not be employed without 
access to alternative emergency equipment and the ability 
to place a transtracheal airway, should ventilation and trans- 
laryngeal intubation prove impossible after paralysis. With 
patients who present obvious anatomic or medical con- 
traindications to DL, the practitioner should entertain 
alternative techniques for intubation as the initial option 
and assemble the appropriate personnel and equipment. 


In recent years, a proliferation of choices has evolved 
for intubation and management of the difficult airway. 
Almost a decade of guideline promulgation has set the 
stage for evolution of respiratory care standards that man- 
date an organized approach to management of the difficult 
intubation. Awake intubation and other alternative intuba- 
tion approaches are recommended when direct laryngos- 
copy is likely to be more risky or more difficult than usual. 
When direct laryngoscopy is attempted and is difficult, 
only a limited number of attempts should be made before 
alternative options are selected. Practitioners should be- 
come skilled with the use of intermediate airways that can 
rescue them from a difficult airway situation. The unex- 
pectedly difficult laryngoscopy, together with a difficult 
mask airway, requires immediate action — not persistent 
attempts to intubate by DL. Monitors of ventilation and 
oxygenation improve the practitioner's ability to recognize 
difficult ventilation and/or the success of intubation. 

No single group that provides acute respiratory care has 
total responsibility for airway management: therefore, dif- 
ficult intubation guidelines will be applied to each group 
or department involved. All respiratory therapists, regard- 
less of training background, will be held to the same stan- 
dard of care for difficult airway management. 

Along with the need for individual institutions and prac- 
titioners to join in formulation of internal standards that fit 
national guidelines comes a need for equipment mainte- 
nance and an ongoing program of training. Training and 
equipment policies should be modeled after those required 
for compliance with national ALS or advanced trauma life 
support protocols. Tracheal intubation is required in the 
field, the emergency department, the operating room, the 
special care units, and on the wards of our medical insti- 
tutions. This establishes a burden of organization and train- 
ing that is shared by all areas and staff who participate in 
cardiopulmonary critical care. 


Respiratory Care • July 1999 Vol 44 No 7 

Prediction of a Difficult Intubation 


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Durbin: Did you say that the abihty 
to provide a surgical airway is an ap- 
propriate and essential component of 
the management of the difficult air- 
way? Is it necessary to be able to pro- 
vide this airway? 

Watson: I believe it is. We haven't 
done an emergency tracheostomy in 
our operating room in some time, be- 
cause we have highly expert individ- 
uals who use alternative modes of rec- 
ognizing and approaching difficult 
airways. However, the fact that the 
emergency medicine and trauma com- 

munity has adopted this makes it in- 
evitable. There is no reason why per- 
cutaneous or direct transtracheal 
airway insertion must be fraught with 
the kinds of difficulties that were re- 
ported out of the Korean War experi- 
ence or that are reported in the epi- 
sodic experience of poorly trained 


Respiratory Care • July 1999 Vol 44 No 7 

Prediction of a Difficult Intubation 

individuals. Tiiis procedure is like any 
other emergency medical procedure, 
and if it's taught and supervised ap- 
propriately, it will have a high prob- 
ability of successful outcome and a 
lower complication rate than in the 
random, sporadic, poorly monitored 
setting that we're used to hearing 

Durbin: I agree with you in princi- 
ple, but the development of expertise 
is a problem. The needle cricothyroid- 
otomy is a way to make people feel 
like they're doing a surgical airway 
without incurring as much risk. But 
this airway approach has many prob- 
lems. With the high pressures in- 
volved, dissection of gas into soft tis- 
sues can occur even if the catheter is 
in the tracheal lumen. It doesn't really 
work very well. But it does give peo- 
ple something to do when they reach 
the point of "can't intubate/can't ven- 
tilate" in a patient who might die. Our 
emergency medical technologists are 
capable of doing a surgical cricothy- 
roidotomy. They are experienced in 
intubating, so when they reach the 
point of "can't intubate/can't venti- 
late," there really is nothing else for 
them to do. I worry, though, that few 
people will get enough experience to 
do a cricothyroidotomy or emergency 
tracheostomy and will not be able to 
do it well when it's needed. How can 
anyone practice this procedure in a 
realistic setting? How can one actu- 
ally be good at it when the time comes? 
We can't have an ear-nose-throat sur- 
geon sitting there ready to do it in 
every hospital 24 hours a day. But 
that's probably what it takes to guar- 
antee quality and safety with a surgi- 
cal approach. 

Reibel: You really can't practice that 
operation. I've done maybe 2 or 3 in 
18 years, and it makes me shudder to 
think about it. It always takes longer 
than you think. There's no way one 
can really be facile at that operation. 
You just do the best you can. 

Watson: I appreciate that point. You 
know it was not long ago that we were 
doing cricothyroidotomy for tracheal 
ticklers and other therapeutic proce- 
dures — cricothyroid aspirations for di- 
agnostic purposes. Cricothyroidotomy 
is not an inherently dangerous proce- 
dure. Though it's inconceivable that a 
community hospital emergency room 
could afford to have someone regu- 
larly available who can do a 2-minute 
surgical tracheostomy with great reli- 
ability, emergency skills can be prac- 
ticed on animals. 

Reibel: I would contend that a cri- 
cothyroid insertion that you just al- 
luded to is not in the emergency pa- 
tient whom you can't intubate or 
ventilate. Those little procedures that 
can be done expeditiously are in thin- 
necked individuals who you can po- 
sition appropriately. The situation of a 
big burly guy with obstructive sleep 
apnea and a big tongue, who is bleed- 
ing after an elective tonsillectomy, is 
where I would defy you to insert that 
tube expeditiously. 

Hurford: These were the consider- 
ations that we had when we made our 
recommendation for our hospitals 
where we have trauma surgeons, or 
senior surgeons available 24 hours a 
day, 7 days a week. When these rare 
situations occur, the last thing you 
want is an inexperienced individual 
with no prior experience in neck sur- 
gery to do the procedure and start in- 
sufflating high pressure air into the 
neck. This cuts off any possibility that 
when the trauma surgeon arrives the 
procedure can be performed success- 
fully. The recommendation for our 
programs was for our programs be- 
cause these are Level One trauma cen- 
ters and there ' s plenty of people around 
who have a great deal of expertise in 
managing the surgical airway. I didn't 
see the point of having anesthesia res- 
idents who would be inadequately 
trained under the best of conditions 
and who would use it under the worst 

of condition.s — maybe once or twice 
in their entire careers — doing that pro- 
cedure. Needle cricothyroidotomy has 
a significant complication rate when 
you're combining it with high pres- 
sure ventilation — and that complica- 
tion rate then prevents the proper sur- 
geon from doing the proper procedure 
and saving the patient's life under the 
worst of conditions. It seems that 
you're ending up taking the most 
poorly trained individual and putting 
them in that position. 

Watson: With due respect, I don't 
believe I said that. What I said was 
that each institution needs to have a 
protocol that incorporates an approach 
to the difficult airway and an approach 
to the "can't intubate/can't ventilate" 
situation. I could produce precisely 
analogous situations with tracheal in- 
tubation or any other emergency thing 
that we do. I appreciate the fact that 
inexperienced people can't do certain 
things, but 1 would ask who or what 
approach we're going to take to the 
"can't intubate/can't ventilate" situa- 
tion when you have someone with the 
credentials that you've defined as be- 
ing adequate for translaryngeal intu- 
bation, and when other alternative air- 
ways are not working? We know those 
situations exist. 

Hurford: The problem we have 
right now is not below the airway. The 
problem right now is that the laryn- 
geal mask airway, while it's in the 
ASA algorithms, hasn't made it to the 
emergency rooms in the country, 
hasn't made it to the ambulance crews 
and paramedics, other than in a few 
places. The promulgation of an ade- 
quate alternative to a bag and mask 
airway will solve many of the prob- 
lems for which cricothyroidotomies 
are now being performed. I've re- 
viewed cases where emergency crico- 
thyroidotomies were performed by 
people with no prior experience on a 
patient who is spontaneously breath- 

Respiratory Care • July 1999 Vol 44 No 7 


Prediction of a Difficult Intubation 

ing. I can't see why something hke 
that should have been done. 

Watson: It would be interesting to 
hear others" views about this issue. 
Clearly you feel very strongly about 
that, but I know of people who've 
muffed LMA insertions, too. I would 
submit to you that this is a dynamic, 
changing environment. The emer- 
gency medicine people 1 know are 
teaching use of the LMA. There are 
also segments that are teaching the use 
of the PTL airway. There's quite an 
argument over what should be. We all 
saw people the esophageal obtu- 
rator airways for years, and they were 
banished because of the same kinds of 
condemnation that you're citing with 
respect to cricothyroidotomy, so I'm 
not prepared to accept any argument 
about which is the best airway inter- 
vention. However, I strongly believe 
that the data support the notion of an 
organized approach to the difficult air- 
way, which should include alternative 
airways and rescue therapies, and 
should probably include some type of 
transtracheal airway. But I'd be curi- 
ous to hear what others have to say. 

Bishop: Bill (Hurford), I've listened 
to you repeatedly condemn cricothy- 
roidotomy, and while I agree it's not 
something you want to see happening 
too much, I know there is the occa- 
sional situation where it can be life- 
saving. I remember a very thin patient 
with osteogenesis imperfecta who had 
started to seize from hypoxia, could 
not be intubated from above, couldn't 
be ventilated, and his life was saved 
by a cricothyroidotomy. It was the first 
one I'd done, but I'd studied the anat- 
omy, I'd done a lot of cricothyroid 

punctures, and I have no regrets. In 
fact, it was absolutely the right thing 
to do. So, I appreciate what you're 
saying, because I've also seen crico- 
thyroidotomy done in the field on pa- 
tients in whom it probably shouldn't 
have been done, where patients may 
have been paralyzed too soon or in- 
appropriately. But, I don't think we 
should say "never." I think there may 
be indications for it. I've also seen jet 
ventilation via cricothyroid puncture 
be life-saving in a patient who bled 
into an epiglottic tumor. So, there are 
the occasional cases, and I don't think 
we should condemn it absolutely. 

Watson: I think this is a quality as- 
surance issue that you're raising. You 
have individuals who are inadequately 
trained, inadequately supervised, and 
where the follow-up is inadequate, 
who are trying to do a procedure that 
they don't know the indications for or 
have the ability to perform. The bur- 
den on us is within our systems — that 
quality assurance be a living process 
that we continue to follow. You can't 
have respiratory therapists doing intu- 
bations and recognizing the difficult 
ones and calling for help if you don't 
review the ones that they call for help 
with and the ones that they don't call 
for help with. You can't have anes- 
thesia residents doing that. You can't 
have pulmonary physicians doing that. 
This is a requirement in our institu- 
tions. And in the region, in our EMS 
system, it's a requirement. Every one 
of those events is reviewed by a qual- 
ity assurance council. The solution is 
adequate follow-up and quality assur- 
ance of an appropriate protocol — not 
condemnation of a piece of the proto- 

col out of proportion to the rest of the 
data. And, clearly we do need more 
data because we don't have real infor- 
mation about what the absolute safest 
approach is. 

Hurford: Agreed. We don't have 
any sort of substantial data on the 
safety, efficacy, and complication rates 
of the emergency cricothyroidotomy 
or the needle cricothyroidotomy with 
jet ventilation under the conditions that 
we're discussing. I also agree that there 
are situations where needle cricothy- 
roidotomy is appropriate, but I would 
condemn the algorithmic approach, 
where there is an enthusiasm to move 
very quickly to a surgical airway with- 
out adequate consideration of the al- 
ternatives, including calling for con- 
sultation. While the algorithms that 
have been discussed here are very rea- 
soned and academic, unfortunately, 
what I have seen out in some places is 
an approach that doesn't follow the 
same rigorous thought processes. 
That's what I'm condemning. 

Watson: I concur. I think the model 
of advanced cardiac life support should 
be reviewed. In most institutions, ev- 
ery code is reviewed in some detail, 
and senior medicine residents who fail 
to treat algorithms appropriately get 
beat up. The anesthesia component of 
the response and the respiratory ther- 
apy component of the response is dealt 
with when it fails to meet those needs. 
I think this will happen with airway 
management. And I think a two-tiered 
system is inevitable because you sim- 
ply cannot provide the most expert in- 
dividual on the scene on every occa- 
sion. It's not feasible in today's world. 


Respiratory Care • July 1999 Vol 44 No 7 

Extubation and the Consequences of Reintubation 

Robert S Campbell RRT 


Separation of Weaning and Extubation Criteria 
Standard Extubation Criteria 
Extubation Failure 
Significance of Extubation Failure 

[Respir Care I999:44(7):799-8031 Key words: intubation, extubation, reintu- 
bation, extubation failure, ventilator weaning. 


Separation of Weaning and Extubation Criteria 

Clinical use of artificial airways is similar to, and often 
necessitated by the need for mechanical ventilation. Sim- 
ilar to initiation of mechanical ventilation, the primary 
goal from the moment of placement of the artificial airway 
is to prepare and evaluate the patient for its removal. In the 
majority of cases, use of an invasive artificial airway is 
intended as a temporizing therapy that should be discon- 
tinued at the earliest appropriate time, but clinical and 
philosophical arguments are commonplace about what is 
the earliest appropriate time. A review of current literature 
on this topic suggests that there are serious risks related to 
the duration of invasive artificial airways.'-^ Our primary 
goal should be to minimize these risks as soon as possible. 
We should attempt to identify and employ well-detmed, 
reliable measures and tests for predicting successful extu- 
bation, while recognizing that some patients will fail ex- 
tubation despite the best prediction efforts of highly knowl- 
edgeable and experienced clinicians. This paper discusses 
the predictors and measures that may be helpful in reduc- 
ing the incidence of extubation failure, with an emphasis 
on information that may be confusing or misleading in 
predicting successful extubation. The etiology of extuba- 
tion failure, treatment options, and clinical ramifications 
of reintubation are also reviewed. 

Robert S Campbell RRT is affiliated with the Department of Surgery, 
Divi.sion of Trauma/Critical Care, University of Cincinnati College of 
Medicine, Cincinnati, Ohio. 

Correspondence: Robert S Campbell RRT. Department of Surgery, Di- 
vision of Trauma/Critical Care. University of Cincinnati College of Med- 
icine. 2.^1 Bethesda Avenue. Cincinnati OH 4.'5267-0.';.'iX. E-mail: 

Before assessing a patient's readiness for extubation, 
the indications for use of invasive artificial airways should 
be reviewed, with specific attention to the indications that 
necessitated intubation for each particular patient. Hess 
has described in detail the accepted indications for use of 
invasive artificial airways.** Accepted indications for place- 
ment of invasive artificial airways include: ( 1 ) mainte- 
nance of the upper airway, (2) protection of the lower 
airway, (3) application of positive pressure to the lower 
airway or need of high oxygen concentrations, and (4) 
facilitation of pulmonary toilet. The indications for intu- 
bation and mechanical ventilation should be clearly delin- 
eated in the clinician's mind. Currently accepted indica- 
tions for the use of positive pressure mechanical ventilation 
include: (1) apnea, (2) acute ventilatory failure, (3) im- 
pending ventilatory failure, (4) intentional respiratory al- 
kalosis (closed head injury), and (5) refractory hypoxemia. 
Although facilitation for mechanical ventilation appears 
on the list of indications for invasive airways, it is well 
accepted that in certain circumstances noninvasive posi- 
tive pressure ventilation is a valid alternative to intubation 
and may offer better patient comfort and improved out- 
come. ■*■"' A common misconception is that the need for an 
invasive airway is a valid indication for mechanical ven- 
tilation. Many patients have the ability and cardiopulmo- 
nary reserves to maintain a normal breathing pattern and 
acceptable gas exchange but at the same time do not have 
the reflexes necessary to control the upper airway. If neu- 
romuscular blockade and/or sedation are used as part of 
the intubation procedure, a short course of mechanical 
ventilation will ensue. Determining the continued need for 
and benefit from mechanical ventilation and invasive air- 
ways independent of each other is essential. Successful 

Respiratory Care • July 1999 Vol 44 No 7 


removal of the artificial airway is an inappropriate end- 
point for the weaning and discontinuance of mechanical 

There are 4 accepted techniques to wean mechanical 
ventilation: (1) unassisted spontaneous breathing periods 
(T-piece trials) interposed with periods of full ventilatory 
support; (2) intermittent mandatory ventilation (with or 
without pressure support) to partition a percentage of the 
necessary work of breathing (WOB) between the ventila- 
tor and patient; (3) pressure support ventilation to partition 
the breath-by-breath WOB between the ventilator and the 
patient; and (4) abrupt discontinuation of ventilatory sup- 
port. To date, no study has shown a significant advantage 
of any one technique. In terms of evaluating the patient's 
ability to sustain spontaneous ventilation, unassisted spon- 
taneous breathing trials appear to be the most predictive 
and efficient method. A state-of-the-art weaning protocol 
would include an initial assessment of the patient's breath- 
ing ability and mechanics by measuring the standard pre- 
diction factors and criteria of weaning success: respiratory 
rate, tidal volume, minute volume, and maximum inspira- 

tory pressure. If the patient displays the ability to breathe 
spontaneously, a daily 20-minute unassisted breathing trial 
should be done to determine the patient's breathing pat- 
tern, mechanics, and gas exchange in the absence of ven- 
tilatory assistance. Patients who pass the initial unassisted 
spontaneous breathing trial should not be returned to the 
mechanical ventilator, and would be abruptly discontinued 
from ventilator assistance. Patients who fail the initial un- 
assisted spontaneous breathing trial require weaning with 
one of the aforementioned techniques. Weaning in this 
case involves the titration of ventilatory support in the 
period between the daily unassisted spontaneous breathing 
trials. Independent of the technique chosen, the goal should 
be to provide a level of ventilatory assistance that avoids 
fatigue of the respiratory muscles, results in an acceptable 
breathing pattern and gas exchange, and maintains patient 
comfort and general well-being. Mechanical ventilation 
weaning and titration of ventilatory support are best ac- 
complished with an accepted weaning protocol."'- There 
are several reports that weaning protocols tend to reduce 
the duration of mechanical ventilation without increasing 

Table 1 . Extubation Criteria to Evaluate for Continued Need of Invasive Airway 

General Criteria 

Specific Tests, Values, and Conditions 

Adequate gas exchange during unassisted spontaneous 
breathing trial 

Adequate respiratory muscle strength 

Acceptable pulmonary mechanics 

Adequate airway protective reflexes 

Normal, improving, or manageable pulmonary secretions 

Stable hemodynamic function 

Presence of a gas leak around the deflated cuff upon 
delivery of a positive pressure breath 

No anticipation for the need for reintubation in the 
near future 

Absence of previously identified difficulties with intubation 

Ratio of arterial oxygen tension to fraction of inspired oxygen (PaOj/Flo,) > 250 

Appropriate pH and PacOj 

Ratio of ventilatory dead space to tidal volume (V,7V.|^) < 0.6 

Maximum inspiratory pressure < -30 cm H,0 

Vital capacity > 15 mL/Kg 

Transdiaphragmatic pressure during spontaneous breathing < 15% of maximum 

Respiratory rate < 35 breaths per minute 

Tidal volume > 4 mL/Kg 

Ratio of respiratory rate to tidal volume (f/V^.) < 105 during spontaneous breathing 

Respiratory system compliance > 25 mL/cm H, O 

Work of breathing < 0.8 J/L 

Oxygen cost of breathing < 15% of total oxygen consumption 

Tracheal occlusion pressure in the first 100 ms > -6 cm H,0 

Gag reflex intact 
Acceptable cough 
Ability to swallow 
Appropriate mental status 

Secretion volume 
Secretion consistency 

Acceptable blood pressure during spontaneous breathing trial 
Acceptable heart rate during spontaneous breathing trial 
No evidence of cardiogenic pulmonary edema 


Respiratory Care • July 1999 Vol 44 No 7 


the complication or reintubation rate. Once the patient 
passes an unassisted spontaneous breathing trial, he or she 
should be considered "weaned." At that point, criteria for 
the removal of the artificial airway should be assessed. 

Standard Extubation Criteria 

Standard extubation criteria are designed to evaluate the 
patient's ability to maintain the upper airway, protect the 
lower airway, and maintain adequate pulmonary toilet. Ba- 
sic evaluation involves determination of adequate gag, swal- 
low, and cough reflexes and abilities. The patient's mental 
status should also be evaluated to determine his or her 
ability to protect the lower airway, follow basic instruc- 
tions, and perform common postextubation respiratory ma- 
neuvers such as incentive spirometry, cough, and deep 
breathing. The amount and consistency of pulmonary se- 
cretions should also be evaluated. Table I lists standard 
extubation criteria, each of which has some predictive value. 
Evaluation of these criteria is more an art than a science, 
since most of the criteria are not simple pass/fail tests. The 
decision whether to risk removal of the artificial airway is 
largely based on the practitioner's experience and on his or 
her interpretation of the patient's history and clinical course. 
Occasionally, additional testing, such as evaluation of the 
patient's ability to breathe around the occluded artificial 
airway with the cuff deflated,'^''* and measurement of the 
percentage of tidal volume leaked around the tube with the 
cuff deflated,"'^ can aid in the decision-making process. 
Bronchoscopy and/or direct laryngoscopy may be useful 
in certain patients with upper airway deformities or edema. 

Extubation Failure 

No matter how diligent the clinician is in performing the 
extubation assessment, successful extubation will never be 
100% predictable. Reported failure rates for planned ex- 
tubation range from 4%-23%. '''--'' This range is primarily 
the result of the aggressiveness and general philosophy of 
the individual clinician or clinician group, and to a lesser 
degree may reflect the patient population studied or indi- 
vidual patient characteristics. The risks of the continued 
presence of the artificial airway must be weighed against 
the risks of extubation and potential extubation failure. An 
extubation failure rate of 10-19% seems to be clinically 
acceptable. This will obviously depend on the patient pop- 
ulation and the duration of intubation and mechanical ven- 
tilation. Patients in the post-anesthesia recovery unit or the 
cardiac intensive care unit (ICU), who are intubated and 
mechanically ventilated for short periods of time should 
have an extubation failure rate of less than 6%.'^ Patients 
requiring mechanical ventilation for more than 48 hours 
because of underlying lung pathophysiology or decondi- 
tioning of the respiratory muscles, or who require pro- 

longed weaning of ventilatory support, would be expected 
to have higher extubation failure rates, approaching 20%.'*^ 
Lower extubation failure rates suggest that some patients 
may be undergoing inappropriately prolonged intubation 
and/or mechanical ventilation. Higher failure rates may 
suggest that some patients are being extubated prematurely 
and exposed to additional risks following extubation and 
related to the replacement of the artificial airway. Tracking 
extubation failure rates is a classic quality assurance index 
that can lead to a better understanding of the factors in- 
fluencing success, improvement of care management, and, 
possibly, improvement of patient outcomes. 

Many studies have retrospectively reported the incidence, 
timing, and reason for extubation failure, but without con- 
trolling for independent variables. Usually the reasons for 
extubation failure are divided into 2 categories: airway 
related and nonairway related. The timing of extubation 
failure is correlated most closely with the etiology of fail- 
ure, with airway related failures typically occurring ear- 
ly — less than 8 hours after extubation. Airway-related ex- 
tubation failure is usually associated with upper airway 
obstruction, resulting from laryngospasm, laryngeal edema, 
supraglottic obstruction, or aspiration of upper airway or 
gastric secretions. Nonairway-related failures can occur up 
to 72 hours post-extubation, and are usually associated 
with impaired gas exchange (hypoxemia, hypercarbia) or 
excessive WOB from worsening pulmonary mechanics. 

Dojat et aP"* recently evaluated a knowledge-based sys- 
tem for deciding when to wean and extubate their patients. 
The knowledge-based system predicted failure in all 10 
patients who had also failed traditional predictors collected 
during and following an unassisted spontaneous breathing 
trial. In 28 patients who were considered to have passed all 
of the traditional predictors, the knowledge-based system 
disagreed in 9 patients. Extubation failure rate was 8% 
when there was agreement between the knowledge-based 
system and traditional predictors, and 23% when there was 
disagreement. This study suggests that collection and eval- 
uation of additional information over traditional simple 
predictors may provide better prediction of negative out- 
come after patients have passed the spontaneous-breathing 

It is a commonly held belief that the WOB will be 
reduced following removal of the artificial airway. Recent 
studies have shown that post-extubation WOB actually 
increases in many patients, most likely because of incom- 
plete control of the upper airway. ™-^^ 

It is important to track the incidence of extubation fail- 
ure and complications in patients who experience unplanned 
extubations. Unplanned extubations should be .separated 
into intentional self-extubation and accidental extuba- 
tion.^"^"'-'' Risk factors for predicting intentional self-extu- 
bation include lack of adequate sedation, inappropriate 
ventilator settings, noncircumferential stabilization of the 

Respiratory Care • July 1999 Vol 44 No 7 



airway, and lack of proper hand restraints. Note, however, 
that up to 80% of patients who intentionally self-extubate 
do not require replacement of the artificial airway. This 
high number of successful self-extubations suggests that 
more aggressive evaluation and weaning are appropriate. 
Risk factors for the prediction of accidental extubation in- 
clude mode of ventilation, noncircumferential stabilization of 
the airway, rotational therapy, and frequent bedside proce- 
dures or interventions that require patient movement. Not 
surprisingly, the reintubation rate in this patient population is 
much higher, approaching 85%. However, this still means 
that 15% of the patients believed not to be extubation candi- 
dates could in fact be successfully extubated. 

Significance of Extubation Failure 

As noted earlier, extubation failure rates of 10-19% are 
currently clinically acceptable. In order to accept these 
numbers, evaluation of outcome measures and other com- 
plication rates are necessary, with appropriate comparison 
to successfully extubated patients. Torres et al,"*'' in a study 
of 40 medical patients requiring reintubation, were among 
the first to quantify the relationship between reintubation, 
mortality, ICU days, and incidence of pneumonia. Mor- 
tality (35% vs 20%), ICU length of stay (19.4 vs 13.9), and 
incidence of pneumonia (47% vs 10%) were all higher in 
patients requiring reintubation, compared to a matched 
group of control subjects who were successfully extubated. 
Epstein et al'** recently reported on 289 consecutive extu- 
bations of medical patients. They reported a 15% reintu- 
bation rate, and the mortality among patients failing extu- 
bation was more than 3 times greater (43% vs 12%) than 
those successfully extubated. In addition, ICU length of 
stay (21 days vs 5 days) was longer in the group that failed 
extubation, as were hospital days (31 days vs 16 days). 

In a study that included 484 patients, Esteban et aP" 
reported an overall reintubation rate of 19%. ICU mortal- 
ity was significantly higher in the group requiring reintu- 
bation (27% vs 3%). More recently, Epstein et al'^ at- 
tempted to determine the factors associated with 
reintubation and mortality. Of 74 patients requiring rein- 
tubation, 69% were associated with nonairway-related fail- 
ure. Overall mortality was 42%, but mortality was much 
higher when the etiology of extubation failure was non- 
airway related (53% vs 17%). There was also an associa- 
tion between mortality and time to reintubation. Mortality 
was 24% in patients reintubated within 12 hours and 51% 
when reintubation occurred more than 12 hours after ex- 
tubation. Another interesting finding in this study was that 
the time to reintubation was, on average, 10 hours earlier 
if failure was related to the airway, as compared to non- 
airway failures. This study illustrates the problems asso- 
ciated with correlating mortality and other outcome mea- 
sures to the need for reintubation alone. Obviously, airway 

related extubation failure is easier to identify and treat 
clinically. Patients who fail extubation for nonairway re- 
lated reasons are commonly treated with other modalities 
before the decision to reintubate is made. This study in- 
dicates that the increased mortality is not associated with 
the reintubation procedure. But is the mortality associated 
with the time period and therapy administered between 
extubation and reintubation? Is it associated with other 
factors such as the underlying disease state and other co- 
morbid conditions? Or is it associated with the subsequent 
prolongation of intubation and mechanical ventilation? 
Certainly, more prompt identification of nonairway-related 
failure, and timely intervention (possibly including a trial 
of noninvasive positive pressure ventilation) and earlier 
reintubation would be associated with lower complication 
and mortality rates. It is well accepted that the duration of 
mechanical ventilation alone is related to mortality. Tro- 
che and Moine^^ reported a mortality rate of 24% when the 
requirement for mechanical ventilation was less than 4 
days, compared to a mortality of 56% if more than 4 days 
of mechanical ventilation were required. The reintubation 
rate in this study was only 4%, and reflected a predominantly 
surgical patient population. Daley et aH' also correlated mor- 
tality and reintubation in a group of 405 trauma patients, and 
found that the overall reintubation rate was low (7%), and 
that there was no difference in mortality between patients 
requiring reintubation and those successfully extubated. 


Removal of the artificial airway is the goal of therapy 
beginning at the time of initial placement, and should be 
done at the earliest appropriate time. However, determi- 
nation of patient readiness for extubation is difficult be- 
cause some of the extubation criteria are subject to inter- 
pretation. The extubation procedure itself is associated with 
few complications, but the need for reintubation is asso- 
ciated with many reported complications and increased 
mortality and morbidity. Although the relationship between 
reintubation and increased mortality and morbidity remains 
unclear, clinicians should diligently monitor patients in the 
postextubation period and promptly provide appropriate 
care and procedures to improve patient comfort, safety, 
and outcome. Reintubation rates should be monitored in 
each institution and within different care areas in order to 
improve the quality of care and aid decision makers in 
augmenting and improving their clinical practice. 


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Dojal M. Harf A. Touchard D. Laforest M. Lemaire F. Brochard L. 
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Shackford SR. Virgilio RW. Peters RM. Early extubation versus 
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29. Gillespie DJ. Marsh HM. Divertie MB. Meadows JA 3rd. Clinical 
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Straus C. Louis B. Isabey D. Lemaire F. Harf A. Brochard L. Con- 
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35. Boulain T. Unplanned extubation in the adult intensive care unit: a 
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Respiratory Care • July 1999 Vol 44 No 7 

8(i < 



Bishop: About 15 years ago, Hen- 
ning Pontoppiden came as a visiting 
professor at Harborview and made 
rounds with our chief of surgery. Pon- 
toppiden said in a discussion about 
patients, "Why don't we just take out 
the tube and see how the patient does? 
No problem if we have to reintubate, 
is it?" Our chief of surgery said, "I 
think it's a very big problem if we 
have to reintubate." So here we had 2 
critical care experts who very much 
disagreed on it. I'm not sure we have 
the evidence, as you point out. My 
personal feeling is: when in doubt, take 
it out. Suppose we have a 30% rein- 
tubation rate? We don't have evidence 
that that has adverse effects, and yet, 
keeping a patient intubated is at least 
costly, and we think probably has risks. 
So where does the 17% come from? 

Campbell: Well, that' s a good ques- 
tion. I thought about rounding that 
number up, and perhaps I should have 
rounded it up, but it's more of a per- 
sonal thing, yet based on most of the 
literature, which indicates that there is 
a less than 20% failure rate. 

Bishop: I would submit that a lot of 
it has to do with how comfortable peo- 
ple feel in reintubating and reintubat- 
ing safely, and I think that's where 
some of the difference comes from. 

Campbell: 1 would agree with that 
as well, and I also think that you have 
to look at the patient population that 
you're dealing with. If you're looking 
at a surgical ICU, then I believe that 
the "when in doubt, take it out" policy 
will probably be successful the major- 
ity of the time. But in the medical 
ICU, that probably would not be the 
case. 1 think there is evidence to sug- 
gest that there might be an altered out- 
come with reintubation in that patient 

Hess: 1 would refer you to the study 
by Esteban, published in the blue jour- 

nal (AJRCCM) about a year ago, 
where they compared 7 cm HjO of 
pressure support to a T-piece for a 
2-hour spontaneous breathing trial, 
and I think had a reintubation rate of 
around 18-20% in both groups.' 


1. Esteban A, Alia I, Gordo F, Fernandez R, 
Solsona JF, et al. Extubation outcome after 
spontaneous breathing trials with t-tube or 
pressure support ventilation. The Spanish 
Lung Failure Collaborative Group. Am J Re- 
spir Crit Care Med 1997; 156(2 Pt 1):459- 

Campbell: It was 19%. 

Hess: But one of the issues that was 
brought out in that paper was that the 
patients who were reintubated in ei- 
ther group had a significantly higher 
mortality than those who were not re- 

Durbin: The crux of the issue is 
whether those patients have a worse 
outcome because they were reintu- 
bated or because they were sicker and 
therefore needed reintubation. The 
question is whether the process of re- 
intubation or the period of inappropri- 
ate extubation is the cause of the poorer 
outcome. There's really no way that I 
can analyze the data any better than 
you did in your presentation. I don't 
think that it is the process of intuba- 
tion that causes the trouble, but we 
really don't know. I believe it's some- 
thing else about the patient. I don't 
think we know the answer, because 1 
don't think we collect or present the 
data in a way that's very meaningful. 
We don't know yet whether it's some- 
thing about reintubation, or being ex- 
tubated for a short period of time, or 
whether these are just sicker patients. 
I challenge you all to think about this 
problem, because I believe we need 
that answer in order to know what to 
do differently and better. 

Hurford: I agree there are no real 
data. But, it would be very odd for 
someone in a post-anesthesia care unit 

or someone in an operating room man- 
agement position to think that it's OK if 
20% of the patients in the post-anesthe- 
sia care unit have to be reintubated after 
general anesthesia, going on the assump- 
tion that there's no harm or additional 
risk with reintubation. Charlie (Durbin), 
I'd like your comment. 

Durbin: The post-anesthesia care 
unit is an interesting environment to 
study, because it looks like patients 
who require reintubation in a post-an- 
esthesia care unit (which you would 
think would be a healthier group of 
patients) might be a good model to 
look at to see if the reintubation process 
is a problem, and it turns out it is. The 
patients who require reintubation in the 
post-anesthesia care unit have a higher 
incidence of pneumonia and have longer 
hospital stays. These data are not cor- 
rected for severity of disease. '"'^ 


1. Mathew JP, Rosenbaum SH, O'Connor T, 
Barash PG. Emergency tracheal intubation 
in the post-anesthesia care unit: physician 
error or patient disease? Anesth Analg 1 990; 

2. Miller KA, Harkin CP, Bailey PL. Postop- 
erative tracheal extubation. Anesth Analg 

3. Berg H, Roed J, Viby-Mogensen J, 
Mortensen CR, Engbaek J. Skovgaard LT, 
Krintel JJ . Residual neuromu.scular block is 
a risk factor for postoperative pulmonary 
complications: a prospective, randomized, 
and blinded study of postoperative pulmo- 
nary complications after atracurium, vecu- 
ronium and pancuronium. Acta Anaesthe- 
siol Scand 1997:41:109.5-1103. 

Hurford: Then why should the 
ICU's environment be any different? 

Durbin: I don't know that it is. But 
I still don't know the answer to the 

Hurford: But it's OK to have a 20% 
reintubation rate in the ICU on the 
basis of the data that we currently don't 

Durbin: If you ventilate patients for 
extended periods, a 20% reintubation 


Respiratory Care • July 1999 Vol 44 No 7 


rate may be reasonable. In fact, we 
may be performing an extubation trial. 
I've used that term in the extubation 
clinical practice guideline.' During its 
review, a lot of people did not like 
that. They thought that an extubation 
trial was not something we should dis- 
cuss. But the words "extubation trial" 
are present, because I think that is 
something anesthesiologists describe. 
It is a successful method for making 
the final determination of extubation 
readiness — fully expecting that some 
patients will need reintubating. 


1 . AARC Clinical Practice Guideline. Removal 
of the endotracheal tube. Re.spir Care 1999; 

Thompson: I would argue that the 
post-anesthesia care unit and ICU are 
very different settings. In the post-an- 
esthesia care unit patients required air- 
way management for a surgical pro- 
cedure. The vast majority are fairly 
healthy — few have multiorgan system 
failure. They were breathing indepen- 
dently prior to surgery. One expects 
that the vast majority will breathe well 
after surgery; so, a failure rate of 20% 
would be extraordinary. ICU patients 
have many reasons for intubation and 
are in a recovery period that can be 
difficult to judge. I agree with Charlie 
that sometimes the only way to know 
with certainty if they can breathe is to 
allow them to try. The other point is 
that we shouldn't delude ourselves to 
think that we are always "protecting" 
our ICU patients. Sometimes doing 
something longer only adds risk, rather 
than providing benefit. It may be en- 
tirely reasonable to allow a failed extu- 
bation rate of 1 in 5, because that means 
that 4 of 5 have successfully made the 
transition back to spontaneous breath- 
ing and are not at risk for the multiple 
complications associated with intuba- 
tion and mechanical ventilation. 

Hurford: An excellent point. Take, 
for example, a patient who has under- 
gone lung volume reduction surgery. 
In those cases, you really want to get 

them extubated and off the ventilator, 
because they can't be mechanically 
ventilated well, and a mechanical ven- 
tilation is terrible for them. So there 
you really want to err in the absolute 
other direction. It's very interesting: dif- 
ferent patients respond differently to in- 
tubation and mechanical ventilation. 

Watson: The risk of ventilator-as- 
sociated pneumonia and a whole host 
of things that are associated with 
chronic ventilation that we've had ups 
and downs in believing about — things 
like ventilator "brain" that the neuro- 
surgeons used to believe in — these 
things have to be weighed against the 
other side. (And in this world of in- 
creasing examination of quality assur- 
ance thresholds, there's a widely pro- 
mulgated notion that a reintubation 
rate is some number beyond which 
you should not go.) But I would say 
that the difference between the ICU 
and the recovery room is that people 
in recovery rooms are waking up, and 
they've got leftover drug effects that 
we're waiting to wear off. Increasingly 
now, we're finding the 2 populations 
merging. We often attempt the trial of 
extubation, the trial of therapy with- 
out the pulmonary artery catheter, the 
trial of whatever kind of critical ther- 
apy is conducted in the recovery room 
in hopes of keeping the patient out of 
the ICU or of being able to stage the 
patient into intermediate care. So, 
we're going to have to accept higher 
reintubation rates than 1-2%. I think 
it's very much an institutional issue. 
We don't do lung reduction therapy, 
but in places that do, that's a concern. 
Somebody who has his trachea re- 
sected — we'd like to get the tube out 
pretty soon if we could. There are a 
number of settings where a trial of 
therapy is totally appropriate. And 
there's a risk management issue asso- 
ciated with whom you subject to that 
trial of extubation. I think they have 
to be evaluated. The other subset is 
the subset of people who were diffi- 
cult to intubate, and who are now dif- 
ficult to extubate, and how do you man- 

age those people? I think we have 
newer ways to deal with them that 
enable us to be more comfortable than 
we used to be, while in the old days, 
if someone was hard to intubate, he 
was left with a breathing tube for 3 
months, and then trached because no- 
body wanted to take it on. 

Campbell: I want to discuss the pa- 
tients who have scheduled returns to 
the operating room, maybe every 48 
hours, every 72 hours, maybe weekly. 
How do you manage that? That's very 
controversial in our institution. A lot 
of people want to keep the patient in- 
tubated for the period they are in the 
intensive care unit between operations. 
I've seen patients who get extubated 
12 hours after surgery and reintubated 
4 or 5 more times in the next 2-week 
period. We don't realize an increase 
in mortality, or ventilator-associated 
pneumonia, or tube-associated pneu- 
monia in that patient population. I 
think it's the fact that the patient has 
failed extubation that's important, and 
it's not the reintubation procedure or 
the replacement of the endotracheal 
tube; it's the fact that the patient had 
something underlying that made them 
fail, and I think now we need to look 
at the timing to intervention, and rec- 
ognition of that failure. One thing, by 
the way, that makes me nervous about 
noninvasive positive pressure ventila- 
tion is that in the patients who fail 
extubation, they are likely also to fail 
noninvasive positive pressure ventila- 
tion, and that may very well be a de- 
lay into definitive treatment. So, 
there's still a lot we need to learn about 
this patient group. 

Pierson:* A final comment. One of 
the issues that's emerged from your 
presentation and this discussion is how 
much we are in need of objective data 

* David J Pierson MD. Division of Pulmonary 
Critical Care Medicine. Department of Medi- 
cine, University of Washington, Seattle, Wash- 

Respiratory Care • July 1999 Vol 44 No 7 



about the ability to remove the endo- 
tracheal tube as opposed to the pa- 
tient's ability to breathe spontaneous- 
ly; that is, the separation of weaning 
and extubation, which much of the lit- 
erature has failed to do. Studies by 
Coplin et al' looked at a large number 
of head-injury patients who remained 
comatose to various degrees but who 
met their predetermined weaning cri- 
teria, and observed what the manag- 
ing physicians did with respect to tak- 
ing out the tube.' It was found that 
patients who were extubated sooner 
did better, had fewer pneumonias, had 
shorter ICU stays, and lower costs — 
not too surprising. But, as part of that 

study, an attempt was made to develop 
a set of extubation criteria analogous 
to the weaning criteria. In addition to 
the Glasgow Coma Scale score and 
general condition, they looked at 6 dif- 
ferent factors in an airway care score^ — 
amount and quality of secretions, spon- 
taneous cough and gag, and so forth. 
That score didn't have any correlation 
with the need for reintubation. The 
only 2 factors that did, statistically, 
were whether the patient had needed 
suctioning 3 times or more in the pre- 
ceding 8-hour shift, and whether the 
patient had a spontaneous cough. So, 
in a deliberate attempt to try to find 
associations with the need for reintu- 

bation once people met weaning cri- 
teria, it was disappointing. And it 
would be intuitive, I would think, that 
people who don't cough and who have 
a lot of secretions are going to have to 
be reintubated, and that's, in fact, what 
that study found. 


1. Coplin WM. Rubenf'eld CD. Cooley KD. 
Newell DW. Pierson DJ. When should brain 
injured patients be exiubaled? (abstract) 
Chest 19%; 110; 1 85s. 

2. Coplin WM. Cooley KD. Rubenfeld CD, 
Pierson DJ. An airway care score to aid ex- 
tubation after acute brain injury (abstract). 
RcspirCare 19%;41( 10);950. 

45^" International 

Respiratory Congress 

D E C E M B E R 1 3 - Ife ,_jr-^ 9 9 

Las Vegas^ Nevada 


Respiratory Care • July 1999 Vol 44 No 7 

Tracheotomy: Indications and Timing 

John E Heffner MD 


The Risks of Different Modes of Airway Support 

Acute Complications of Airway Intubation 

Long-term Complications of Airway Intubation 
Benefits of Different Modes of Airway Approach 
Economic Analysis 
A Decision Analysis Approach 
Future Investigation 

[Respir Care 1999;44(7):807-815] Key words: tracheotomy, complications of 
airway intubation, complications of tracheotomy, advantages of tracheotomy, 
timing of tracheotomy. 


During the last 30 years, tracheotomy has become one 
of the most commonly performed surgical procedures in 
critical care medicine. Despite this widespread use, patient 
selection and procedure timing remains controversial in 
ventilator-dependent patients. ' Some experts emphasize the 
surgical risks and costs of tracheotomy and caution against 
its implementation until a patient remains ventilator de- 
pendent for 2-3 weeks. 2 -* Advocates of the procedure 
argue for earlier tracheotomy, emphasizing the benefits of 
a surgical airway and the acceptable risks of tracheotomy 
compared to prolonged translaryngeal intubation.-'' These 
differing viewpoints have spawned numerous observational 
studies and a few randomized, comparative studies that 
seek to establish the "holy grail" of airway management: 
when is the ideal time to perform a tracheotomy?^ 

This review departs from the usual assumption that there 
is an ideal time for tracheotomy, universally applicable to 
all critically ill patients, and maintains that patient selec- 
tion for tracheotomy and the timing of the procedure are 
complex decisions that have no simple, universal solution. 
Decisions regarding tracheotomy have been overly influ- 
enced by analyses of the comparative risks of tracheotomy 
compared to translaryngeal intubation, and insufficient at- 

John E Heffner MD is affiliated with the Department of Medicine. Med- 
ical University of South Carolina, Charleston. South Carolina. 

Correspondence; John E Heffner MD, Department of Medicine, Medical 
University of South Carolina, Charleston SC 29425. E-mail: 

tention has been directed to their relative benefits. This 
review emphasizes the importance of incorporating the 
patient's perspective and unique clinical circumstances into 
the decision of whether to perform a tracheotomy, leading 
to the conclusion that different patients become appropri- 
ate candidates for tracheotomy at varying times in their 
clinical course, and that some patients cannot be expected 
to benefit from the procedure. 

The Risks of Different Modes of Airway Support 

Most discussions of tracheotomy timing have framed 
the argument for delaying tracheotomy in ventilator-de- 
pendent patients in terms of the risks of the procedure 
compared with the risks of prolonged translaryngeal intu- 
bation. Although this approach ignores the relative bene- 
fits of different routes of airway support, procedure-related 
risk is an important component of the decision for airway 
selection. Two categories of risk have been assessed: the 
acute complications and the delayed or long-term compli- 
cations of differing modes of airway support.' 

Acute Complications of Airway Intubation 

Quantification of the early risks of tracheotomy has var- 
ied among reports. Case series performed during the first 
decade of widespread use of "floppy," low-pressure endo- 
tracheal tube cuffs reported a high morbidity from trache- 
otomy. "* Between 4% and 36% of patients experienced 
airway obstruction, bleeding from the stomal incision. 

Respiratory Care • July 1999 Vol 44 No 7 

Tracheotomy: Indications and Timing 

Table I . Early Complications of Standard Surgical Tracheotomy 








Tube (%) 

Bleeding (%) 


Air (%) 



Morbidity (%) 



























6 ; 



< 1 


< 1 

< 1 








n = number. 

overly large or misplaced stomal incisions, or stomal wound 
infections, with an overall morbidity of 66% (Table 1).-^ 

Other clinical centers subsequently reported lower com- 
plication rates from standard tracheotomy, with total mor- 
bidity ranging from 3% to 14% (see Table 1 ).*-" Analysis 
of the pooled data from these later studies estimates the 
overall morbidity from standard tracheotomy to be 7%.'* '^ 
Because the research groups did not employ the same 
definitions to identify procedural complications, it is dif- 
ficult to compare the morbidity data from these studies. 
However, reexamination of earlier reports indicates that 
the high incidence of tracheotomy complications reported 
in these studies may relate to the performance of the pro- 
cedure by trainees from multiple surgical services, often 
with limited supervision by senior physicians.^ Centers 
that reserve tracheotomy to experienced teams report lower 
rates of complications. It appears from available data that 
clinically important, early complications from tracheot- 
omy range from 1% to 7%. 

The acute complications of percutaneous dilation tra- 
cheotomy (PDT) are still undergoing evaluation. Performed 
by Seldinger technique, PDT avoids surgical incision of 
cervical tissue planes and the anterior tracheal wall. Using 
varying definitions to identify complications, recent stud- 
ies report an overall morbidity range between 8% and 23% 
(Table 2). A recent review of the pre- 1995 PDT literature 
(which standardized the definitions of acute complications) 

Table 2. Early Complications of Percutaneous Dilatational Tracheotomy 

reported an overall morbidity from PDT of 7.6%,''' which 
is similar to the incidence of acute complication from stan- 
dard tracheotomy. It appears that PDT, like standard tra- 
cheotomy, can be performed in ventilator-dependent pa- 
tients with an acceptable incidence of morbidity due to 
early complications.''' All contemporary studies support 
the conclusion that mortality from tracheotomy in criti- 
cally ill patients is less than 1%.** 

Other early complications of tracheotomy, such as the 
risk for nosocomial pneumonia, patient discomfort, noso- 
comial sinusitis, and encumbered patient mobility, will be 
discussed as they compare to similar complications from 
translaryngeal intubation. 

The acceptability of risks for acute complications from 
tracheotomy depends on the comparable risks anticipated 
from maintaining the endotracheal intubation. Risks from 
translaryngeal intubation are usually reported as the con- 
sequences of the intubation procedure itself. However, the 
acute complications from translaryngeal intubation that 
should be compared to tracheotomy are the ongoing risks 
of maintaining the endotracheal intubation (Table 3). 

Unplanned extubation is an important complication of 
translaryngeal intubation; it occurs in 8-13% of ventila- 
tor-dependent patients, and results in cardiopulmonary 
complications in 6-31% of instances.'''^''' Nosocomial 
pneumonia, which occurs more commonly in ventilated 
patients who undergo extubation but require reintubation,"* 








Tube (%) 

Bleeding (%) 


Air (%) 



Morbidity (%) 



































n = number. 


Respiratory Care • July 1999 Vol 44 No 7 

Tracheotomy: Indications and Timing 

Table 3. Ongoing Risks from Prolonged Translaryngeal Intubation 

Inadvertent decannulation 
Inability to communicate 
Poor oral care 
Nosocomial pneumonia 
Epistaxis during nasal intubation 
Orthostasis and limited ability to 


Airway discomfort 
Prolonged ICU stay 
Nosocomial sinusitis 
Compromised nutrition 

represents one of the more serious but difficult to docu- 
ment consequences of unplanned extubation. Stauffer et al 
reported a lower incidence of self-extubation when venti- 
lator-dependent patients were converted to a tracheoto- 

Many of the clinically important ongoing complications 
of prolonged intubation relate to the discomfort that pa- 
tients experience from the translaryngeal endotracheal tube. 
Ventilator-dependent patients report that frequent airway 
suctioning, appliances designed to maintain endotracheal 
tube position, and restraints to prevent self-extubation are 
major sources of discomfort and anxiety.''^ Several studies 
indicate that the inability to speak because of the presence 
of an endotracheal tube represents one of the most dis- 
tressing aspects of ventilator dep>endence, and invokes anx- 
iety, frustration, fear, and depression. "-21 Both nasotra- 
cheal and orotracheal endotracheal tubes hinder meaningful 
communication between patients and their families and 
caregivers. Also, prolonged translaryngeal intubation de- 
lays transfer from intensive care unit (ICU) settings to 
step-down or intermediate care units where patients can 
have more frequent interactions with their families and 
lower levels of resource utilization. Translaryngeal intu- 
bation limits patient mobility, such as to transfer to a bed- 
side chair, compared to tracheostomized patients. 

The clinical consequences of patient discomfort, anxi- 
ety, and immobility associated with translaryngeal intuba- 
tion are potentially serious but not well documented. Ag- 
itated, critically-ill patients run a risk that they will be 
oversedated in an effort to manage their motor activities, 
sleeplessness, and apparent psychic discomfort. Overseda- 
tion of ventilator-dependent patients delays successful 
weaning from mechanical ventilation and increases the 
risk of nosocomial pneumonia.-- The pathogenesis of an 
increased risk of pulmonary infection from oversedation 
remains uncertain, but may relate to poor clearance of 
airway secretions because of static body positioning. Con- 
cern regarding the increased incidence of and consequences 
related to heavy sedation in ventilated patients has been 
the subject of recent editorial comment.-' 

Prolonged translaryngeal intubation also presents a risk 
for nosocomial sinusitis. -''--^ A recent prospective, obser- 
vational study by Rouby et al found that 95% of critically 

ill patients ventilated for 7 days through a nasotracheal 
tube develop radiographic evidence of maxillary sinusitis, 
as demonstrated by complete sinus opacification or intra- 
cavitary air-fluid levels.-^ Thirty-eight percent of patients 
with radiographic sinusitis were found to have infectious 
sinusitis when evaluated by sinus aspiration and quantita- 
tive culture techniques. The organisms isolated from in- 
fected sinuses represent the typical Gram-positive and 
Gram-negative bacterial and fungal pathogens that pro- 
duce life-threatening infections in the ICU. Although the 
study by Rouby et al was not designed to establish noso- 
comial sinusitis as a source of systemic infection, patients 
with sinusitis had a 70% risk of developing nosocomial 
pneumonia, compared to a 43% risk for patients with nor- 
mal sinus computed tomography examinations.-'' More- 
over, 38% of patients with ventilator-associated pneumo- 
nia had the same pathogens isolated from their sinuses and 
lower airways. Sinus lavage (without the addition of an- 
tibiotics) resolved clinical manifestations of sepsis in the 
majority of patients. 

Several studies indicate that translaryngeal intubation 
through the oral route does not eliminate the risk of nos- 
ocomial sinusitis.2'*2''.28 Rouby et al observed radiographic 
sinusitis in 23% of orally-intubated patients.-'' These pa- 
tients did not have other nasal catheters, such as sump or 
feeding tubes, that could have been the etiology of sinus- 
itis. It appears that some undefined factors promote nos- 
ocomial sinusitis in intubated patients, in addition to direct 
obstruction of sinus ostia by nasotracheal tubes. 

The incidence of nosocomial sinusitis as a consequence 
of tracheotomy has not been studied. However, in our ICU 
we have rarely identified sinusitis as a cause of fever for 
ventilator-dependent patients managed with a tracheotomy. 

Translaryngeal intubation allows aspiration-'^" and pre- 
sents a major risk for nosocomial pneumonia.'- '''* Place- 
ment of an endotracheal tube through the larynx interferes 
with glottic function and promotes pooling of oral secre- 
tions within the trachea, above the endotracheal tube cuff. 
This reservoir for respiratory pathogens appears to be an 
important source of ventilator-associated pneumonia, as 
indicated by the lower incidence of pneumonia observed 
in patients treated with specialized endotracheal tubes that 
remove fluid above the cuff.^'--" Several studies indicate 
that tracheotomy tubes similarly interfere with glottic func- 
tion.'** Maintenance of normal glottic closure appears to 
depend on preservation of cyclic respiratory air flow across 
the vocal cords. '* Diversion of air flow away from the 
larynx after placement of a tracheostomy removes this 
stimulus to normal glottic closure. This may explain the 
observation that microaspiration persists despite placement 
of a tracheotomy tube.'"-''''-''' 

Though both translaryngeal endotracheal tubes and tra- 
cheostomy tubes interfere with normal glottic function, no 
studies have been published that compare the degree of 

Respiratory Care • July 1999 Vol 44 No 7 


Tracheotomy: Indications and Timing 

aspiration of bacteria-laden, upper airway secretions with 
these 2 modes of airway support. It is suspected that trans- 
laryngeal intubation would result in a greater degree of 
aspiration, because endotracheal tubes pass through the 
vocal cords, resulting in wide-open glottic incompetence. 
This hypothesis agrees with recent observations that the 
incidence of ventilator-associated pneumonia is lower in 
trauma victims with respiratory failure who are managed 
with early tracheotomy compared to prolonged ventilation 
with translaryngeal endotracheal tubes. ' 

Prolonged translaryngeal intubation also complicates 
oral nutrition, which necessitates feeding tube or paren- 
teral nutrition, with their associated risks. Poor oral hy- 
giene is an additional difficulty with prolonged oral intu- 

Long-Term Complications of Airway Intubation 

Tracheotomy presents risks for tracheal stenosis, both at 
the segment of the trachea adjacent to the tracheostomy 
tube cuff, and at the tracheal stoma site."""''* The incidence 
of cuff-related tracheal stenosis has decreased markedly 
with the advent of the high- volume low-pressure tube cuff."" 
Although tracheotomy tube cuffs are slightly lower in vol- 
ume than most similarly-sized endotracheal tubes, no pub- 
lished data disagree with the impression that tracheotomy 
tubes and translaryngeal endotracheal tubes present a sim- 
ilar risk for tracheal stenosis. 

Tracheotomy presents a more clinically important risk 
for tracheal stenosis at the stoma site."* Standard surgical 
tracheotomy entails an incision through the anterior tra- 
cheal wall, which results in healing by cicatrization and 
the potential for tracheal stenosis 1-6 months after airway 
decannulation. It is difficult to estimate the incidence of 
tracheal stenosis after tracheotomy, because of the limited 
number of studies that have conducted careful imaging or 
endoscopic evaluations of the airway on long-term patient 
follow-up after decannulation."** Also, the available obser- 
vational studies vary in their definitions of tracheal steno- 
sis, with airway narrowings & 10-40% qualifying as ste- 
notic lesions. These degrees of stenosis usually do not 
compromise ventilatory function, which develops most of- 
ten in patients who experience more than 50% loss of 
tracheal caliber. Also, the advent of PDT appears to have 
decreased the incidence of tracheal stenosis after decan- 

Table 4 lists the recent studies that examined the risks of 
tracheal stenosis in critically ill patients who have under- 
gone a tracheotomy. It appears that contemporary tech- 
niques of tracheotomy and airway management in the ICU 
result in complication rates between 0% and 16% for tra- 
cheal stenosis from tracheotomy.'*^-'^ The incidence of 
high grade stenosis that requires corrective interventions is 
uncertain, but available data suggest that this complication 

Table 4. Long-Term Risks for Tracheal Stenosis after Tracheotomy 



stenosis (%) 



van Heum''* 

Open 81 16* 
PDT/open 55 
PDT 150 <1 
PDT 9 
PDT 41 7t 

s dilatational tracheotomy: MRI ^ magnetic resonance 
clieotomy. *Deftnition of tracheal stenosis was greater 
ost < 40% airway caliber. 






PDT = percutaneou 
standard surgical tra 
narrowing. iGroup 

imaging; Open = 
than 20% tracheal 

occurs uncommonly in survivors of respiratory failure who 
undergo tracheotomy. 

Although symptomatic tracheal stenosis after tracheot- 
omy decannulation represents an important source of mor- 
bidity, the available corrective surgical interventions for 
tracheal stenosis provide good results in most patients. 
Resection of stenotic segments of the trachea, with pri- 
mary end-to-end anastomoses, can be applied to patients 
with stenotic lesions that extend across as much as 50% of 
the tracheal length.'*3'*"53 

Other long-term complications of tracheotomy include 
swallowing dysfunction, tracheocutaneous fistulae, tra- 
cheo-esophageal fistulae, and neck scars.''"** Only a small 
minority of patients who undergo tracheotomy experience 
any of these complications to a degree that represents a 
major clinical problem. 

The long-term complications of prolonged translaryn- 
geal intubation derive from the impact of endotracheal 
tubes on subglottic structures. The endolaryngeal segment 
of endotracheal tubes flexes toward the posterior endola- 
rynx in the region of the arytenoids and cricoid cartilage 
where the native airway curves anteriorly from the poste- 
rior pharynx (Figure 1).-^"* The endotracheal tube applies 
high wall tensions against these posterior glottic and sub- 
glottic structures. Animal studies indicate that measured 
wall tensions can exceed 200-400 mm Hg^'-'* in these 
regions of the airway. Most of this tension focuses on the 
posterior aspect of the cricoid cartilage, the arytenoid car- 
tilages, and the posterior segments of the vocal cords. ■''^ 

Endotracheal tube wall tension against the posterior as- 
pect of the cricoid cartilage is problematic because the 
cricoid ring forms the structural foundation of the larynx. 
Injury to the cricoid ring can result in involution of laryn- 
geal structures and postextubation subglottic stenosis. In- 
jury to the arytenoid cartilages and posterior segments of 
the vocal cords produces interarytenoid fibrous bands that 
can result in glottic stenosis, glottic incompetence, and 
long-term alterations in voice. Endotracheal tubes can also 
cause vocal cord paralysis.'*-^' 


Respiratory Care • July 1999 Vol 44 No 7 

Tracheotomy: Indications and Timing 



Fig. 1 . Anatomic position of an endotracheal tube in the upper 
airway. The curvature of the tube creates pressure points on pos- 
terior laryngeal structures. The arrows denote contact points that 
can cause damage to the arytenoid cartilages and the postehor 
aspect of the cricoid ring. 

Reports differ on the incidence of complications to glot- 
tic and subglottic structures after translaryngeal intubation. 
Few studies have provided long-term follow-up with care- 
I'ul airway examinations of patients who have recovered 
from critical illness. However, several reports provide some 
insights into the risks for this complication from transla- 
ryngeal intubation. Elliott et al noted in 30 survivors of 
acute respiratory distress syndrome (ARDS) that 3 patients 
required laryngotracheal reconstruction for subglottic ste- 
nosis, which persisted in 2 patients after surgery.''" A pro- 
spective observational study by Whited is frequently 
quoted, because it meticulously assessed patients for air- 
way complications after extubation.''' Whited's results sup- 
port the concept that long-term airway injury commonly 
occurs after translaryngeal intubation and that the inci- 
dence and severity of airway injury correlate with the du- 
ration of intubation. Patients intubated for 2-5 days had a 
6% incidence of transient laryngeal injury. Patients intu- 
bated for 6-10 days had a 5% incidence of chronic laryn- 
geal stenosis. Patients intubated for 11-24 days had an 
1 1% incidence of extensive laryngeal stenosis. 

More recently, Thomas et al reported on 150 consecu- 
tive critically ill adult and pediatric patients who required 
intubation for more than 24 hours for various indications 
and observed that 8.6% had long-term laryngeal sequel- 
ae.''- These sequelae included subglottic stenosis (3.3%), 
vocal cord palsy (2%), tracheomalacia (2%), and bilateral 

vocal cord paralysis (1%). Laryngeal complications were 
especially common in patients with seizures (25%) and 
patients with head trauma (19%). Another prospective 
study, performed by Vukanovic et al, examined 87 pa- 
tients intubated for less than 1 day to as long as 82 days.**^ 
They noted a 34% incidence of subglottic and tracheal 
lesions, which were severe stenoses in 3.4% of the study 
cohort. They noted a significant correlation between du- 
ration of intubation and the severity of tracheal lesions. 
The majority of airway lesions resulted from the endotra- 
cheal tube cuff, the tip of the endotracheal tube, or the 
suction cannulae. 

Holdgaard et al evaluated 379 critically ill, nasotrache- 
ally-intubated patients, of whom 28 1 were available for 
long-term follow up 1-2 years after recovery.''^ Of these 
281 patients, 35% had long-term symptoms from the nose, 
24% had symptoms related to the ears, 20% had maxillary 
sinus problems, 29% had chronic voice problems, and 32% 
had throat complaints. The duration of intubation corre- 
lated with the duration of laryngeal symptoms. 

Other prospective studies have not observed a high risk 
for long-term laryngeal injury in critically ill patients ven- 
tilated through a translaryngeal route, or an association 
between the duration of intubation and the risk of airway 
damage. Colice et al found that in their cohorts of critically 
ill patients, superficial mucosal ulcerations were commonly 
present after extubation, but resolution of airway injury 
occurred during follow-up.'''* '*'' The severity of observed 
airway lesions did not con-elate with the duration of intu- 
bation. Dunham et al examined trauma patients and did not 
identify a correlation between the duration of intubation 
and the incidence of subglottic stenosis." 

It is difficult to reconcile the varying observations from 
these investigations of airway injury from translaryngeal 
intubation. Multiple factors can alter the progression of 
superficial ulcers to deep-seated endolaryngeal lesions,^*'' 
including airway suppuration, systemic hypotension, co- 
morbid conditions, ventilator-induced airway pressure, and 
patient mobility. Therefore, spectrum bias, varying ap- 
proaches to respiratory care, and management of other 
acute conditions may affect the observed outcomes from 
these studies. Also, in contrast to the other reported stud- 
ies,"'-''^ patients reported by Colice et al'''* '"' and Dunham 
et aH did not experience fixed airway stenoses. Thus, it is 
not possible for the latter studies to find a correlation 
between fixed airway lesions and duration of intubation. 
The available patient series indicate that clinically impor- 
tant laryngeal injury occurs in 0-l97f of translaryngeally 
intubated patients.'''''''*-^- Translaryngeal intubation is the 
most common cause of laryngeal stenosis referred to oto- 

It is generally accepted that surgical correction of sub- 
glottic stenosis is more difficult than surgical correction of 
tracheal stenosis caused by a tracheotomy tube.^'' For this 

Respiratory Care • July 1999 Vol 44 No 7 

Tracheotomy: Indications and Timing 

Table 5. Potential Advantages of Tracheotomy Compared to 
Prolonged Translaryngeal Intubation 

Increased patient mobility 

Increased comfort 

Improved airway suctioning 

Early transfer of ventilator-dependent patients from the ICU 

Less direct endolaryngeal injury 

Enhanced oral nutrition 

Enhanced phonation and communication 

Decreased airway resistance for promoting weaning from 

mechanical ventilation 

Decreased risk of nosocomial pneumonia in patient subgroups 

reason, some experts favor conversion to tracheostomy to 
avoid the subglottic lesions associated with prolonged trans- 
laryngeal intubation. 

BeneHts of Different Modes of Airway Support 

As previously discussed, tracheotomy offers several po- 
tential benefits to patient care (Table 5). Patient comfort is 
the major advantage of tracheotomy. '° Patients interviewed 
after recovery from ventilator dependence indicate im- 
proved comfort with tracheotomy intubation. Improved 
comfort may decrease the need for sedation in critically ill 
patients, which has been associated with an increased risk 
of nosocomial pneumonia. ^^ Patient mobility is enhanced 
with tracheotomy. Hemodynamically stable patients can 
move to a chair with less risk of accidental extubation. 
Also, transfer from the ICU is facilitated before weaning 
from mechanical ventilation.^ 

The psychological stress experienced by critically ill 
patients because of inability to communicate has been well 
documented."''-''"^'' Tracheotomy allows articulated 
speech, which enhances a patient's sense of well-being 
and control. ^o-^S'^" 

A tracheostomy tube presents opportunities for oral nu- 
trition in the ventilator-dependent patient,''* which de- 
creases the risk of complications from parenteral nutrition. 
Airway resistance is expected to be lower with a trache- 
ostomy tube than a translaryngeal endotracheal tube, which 
often has increased resistance in vivo because of inspis- 
sated secretions and turbulent air flow.**"**' This advantage 
may explain the observation that trauma patients who un- 
dergo early tracheotomy have shorter periods of mechan- 
ical ventilation and shorter ICU stays than patients with 
prolonged translaryngeal intubation.-'' 

One of the most important potential advantages of a 
surgical airway is that of decreasing the incidence of nos- 
ocomial pneumonia. Rodiguez et al randomized 107 trauma 
patients to early tracheotomy (7 days or less of mechanical 
ventilation) or delayed tracheotomy (greater than 7 days of 
mechanical ventilation), and observed the incidence of nos- 

ocomial pneumonia as diagnosed by clinical criteria.'' They 
noted that 78% of the early tracheotomy patients experi- 
enced pneumonia, compared to 96% of the delayed tra- 
cheotomy patients. Similarly, a retrospective study by 
Kluger et al detected a lower incidence of pneumonia in 
1 1 8 trauma patients converted to a tracheotomy during the 
first week of mechanical ventilation, as compared to at a 
later time in the hospital stay.*- 

The benefits of translaryngeal intubation derive primar- 
ily from the effectiveness of the procedure in providing 
reliable airway access for patients with respiratory failure. 
However, recent advances in respiratory care have empha- 
sized the advantages of noninvasive ventilation**-'' **'' as an 
alternative method for providing an interface with venti- 
lator support in patient subgroups, and avoiding the risks 
of an endolaryngeal tube. There are no ongoing benefits of 
prolonged translaryngeal intubation beyond the provision 
of airway access until patients can undergo successful ex- 
tubation. Most of the management efforts directed toward 
patients with respiratory failure focus on accelerating suc- 
cessful weaning and the removal of endotracheal tubes as 
soon as possible so as to avoid the attendant risks. 

Economic Analysis 

Both tracheotomy and prolonged translaryngeal intuba- 
tion have been claimed to provide cost-effective benefits. 
These differing impressions depend on the perspective 
taken when the relative cost-effectiveness of these inter- 
ventions are considered. For instance, prolonged transla- 
ryngeal intubation saves the cost of tracheotomy, which 
ranges between $1,370 and $2,832 for standard tracheot- 
omy, and between $742 and $1,370 for PDT.^^-gQ How- 
ever, tracheotomy can promote earlier transfer out of ICU, 
thereby decreasing critical care costs that can exceed $ 1 ,000 
a day. Also important is the patient's viewpoint in terms of 
comfort and quality-adjusted analyses. Recently published 
standards for cost-effectiveness research caution against 
concluding that one intervention is more cost-effective than 
another unless rigorous cost-effectiveness evaluations have 
been performed with explicit assumptions and sensitivity 
analyses.'" Such studies have not been conducted for air- 
way management, so no conclusions can yet be made re- 
garding the relative cost advantages of different modes of 
airway support for ventilator-dependent patients. 

A Decision Analysis Approach 

The foregoing review emphasizes the gaps in our clin- 
ical knowledge regarding determining the ideal time to 
perform a tracheotomy in ventilator-dependent patients. 
Existing studies on the relative advantages of different 
modes of airway support have various designs and diverse 
patient populations with small sample sizes and conflict- 


Respiratory Care • July 1999 Vol 44 No 7 

Tracheotomy: Indications and Timing 

ing conclusions.'' Moreover, hardly any data are available 
regarding patients' and patients' families' perceptions of 
the relative desirability of different modes of airway sup- 
port. Clinicians are faced with a difficult task when mak- 
ing airway decisions; these decisions require consideration 
of the disparate functional and anatomic complications 
associated with tracheotomy (tracheal injury) compared to 
translaryngeal intubation (laryngeal injury), and the dif- 
fering benefits anticipated from each mode of airway 
support. ''I 

To appropriately time tracheotomy in ventilator-depen- 
dent patients, clinicians are left with a need to individual- 
ize care.' ''- "^^ Multiple factors determine the possible ben- 
efits of tracheotomy in a given patient. Trauma patients 
(who are at high risk for nosocomial pneumonia) may 
benefit from an earlier conversion to tracheotomy than 
patients with acute exacerbations of chronic obstructive 
pulmonary disease. Patients requiring heavy sedation to 
manage hypoxic respiratory failure are less likely to ben- 
efit from the comfort advantages of tracheotomy than are 
mentally alert patients with respiratory failure due to neu- 
romuscular disease. Patients with bleeding diatheses or 
abnormalities of cervical structures may have a greater 
surgical risk from tracheotomy, justifying a delay of the 
procedure. Because each patient's clinical circumstances 
are unique, it is not possible to determine a standardized 
time, applicable to all critically ill patients, for performing 
tracheotomy. Flexibility in decision-making is necessary 
to address the individual patient's needs and preferences. 
This decision-making approach avoids overly simplistic 
rules that, for instance, promote translaryngeal intubation 
for 2-3 weeks, after which tracheotomy becomes indi- 
cated. No data establish that 2-3 weeks is the outer limit 
of safety for translaryngeal intubation or. conversely, that 
some patients might not benefit from earlier conversion to 
a tracheostomy. 

The conversion to a tracheostomy should be anticipated 
early in the clinical course of every ventilator-dependent 
patient.'-'^'''''* Patients who appear likely to recover from 
respiratory failure and achieve successful extubation within 
a reasonable period of mechanical ventilation can be main- 
tained with a translaryngeal endotracheal tube and reeval- 
uated after a week of care. Patients who demonstrate re- 
spiratory deterioration or failure to improve after 7 days of 
ventilation are unlikely to undergo extubation within the 
next several days. Such patients can be examined to de- 
termine if the benefits of tracheotomy outweigh the risks 
and expense of the procedure. This evaluation should in- 
clude a patient-centered perspective and consider the com- 
fort advantages of the procedure. 
I Some patients may appear to be obvious candidates for 
tracheotomy within the first days of ventilation if the se- 
verity of their critical illness makes recovery unlikely within 
the next 2 weeks. Other patients may never become can- 

didates for tracheotomy because of a grave prognosis for 
survival or recovery of meaningful neurologic function. 

The anticipatory approach of selecting patients for tra- 
cheotomy benefits from the ability of physicians to antic- 
ipate or predict the clinical course of a patient's respiratory 
failure, and prediction models can assist clinicians in iden- 
tifying patients who are unlikely to undergo eariy extuba- 
tion. A report by Heffner et al confirmed the validity of a 
prediction rule (comprised of radiographic findings and 
markers of oxygenation) for identifying patients who were 
unlikely to achieve early extubation after one week of 
ventilation.^'"' A similar model predicted mechanical ven- 
tilation for more than 14 days in trauma patients as deter- 
mined by clinical predictors available on the second day of 
ICU care.'^ 

Future Investigation 

Future investigations should examine the benefits of 
tracheotomy performed at varying times during the course 
of critically ill patients with different underiying condi- 
tions to determine the relative benefits of tracheotomy vs 
prolonged translaryngeal intubation. Such studies will need 
to examine outcomes from patients' and patient families' 
perspectives, and provide long-term observations of de- 
layed complications from the different modes of airway 


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Respiratory Care • July 1999 Vol 44 No 7 


Tracheotomy: Indications and Timing 


Pierson:* In my experience, trache- 
otomy facilitates weaning from me- 
chanical ventilation, although this may 
be as much because of effects on cli- 
nician behavior as any physiologic 
changes. We have a tendency to get 
weaning and extubation so tangled up 
in our minds that we prolong the pro- 
cess of discontinuing ventilatory sup- 
port because we automatically include 
extubation in our thinking, and in mar- 
ginal cases we delay because we're 
afraid that if the patient isn't ready, 
we will have to put the endotracheal 
tube back in. Once the patient has a 
tracheostomy, weaning becomes a 
simple matter of switching the patient 
onto a T-piece, and if they're not ready 
you just hook the ventilator up again. 

Heffner: I think that's true, and 
maybe what we need to do is to take 
a look at the state of the art of how we 
manage airway decisions, and what 
drives our management decisions, 
whether they be physician behavior, 
variable interpretations of clinical 
findings, or the wish to decrease air- 
way resistance. We strive to provide 
interventions that give the best out- 
comes for our patients within the lim- 
its of the medical culture in which we 
practice. You know, I don't do many 
tracheotomies in the ICU. Whenever 
I've talked or written about it, I think 
some readers or listeners have inter- 
preted that I'm arguing for an earlier 
induction of tracheotomy. Actually, 
what I'm trying to argue for is a dif- 
ferent approach to decision-making — 
to try to understand how we make the 
decision, on what bases we make the 
decision, which data we're reading, 
following, and invoking, and then 
monitor our clinical course and out- 
comes. I've got to say, though, with 
not doing many tracheotomies and try- 

* David J Pierson MD, Division of Pulmonary 
Critical Care Medicine, Department of Medi- 
cine, University of Washington, Seattle, Wash- 

ing real hard to extubate people as 
early as possible, we've had a number 
of patients we couldn't wean, and then 
I've been impressed by the fact that 
once we did a tracheotomy, they were 
off mechanical ventilation in a couple 
of days. I think it might be true that 
some patients come off the ventilator 
more rapidly if they have a tracheos- 
tomy in place. Whether it allows me 
then to cut the sedation or talk the 
night nurses into not sneaking the Ati- 
van dose in (because they perceived 
that the patient was uncomfortable) — 
whatever the magic of a tracheotomy 
is, I don't know. But in the limits of 
the culture in which I practice, it seems 
that intervention for subgroups of pa- 
tients does have value for getting them 
off the ventilator earlier. 

Pierson: I'm sure that's true, and 
that my statement was a bit oversim- 

Branson: David (Pierson), we saw 
the exact same thing over and over 
again, and we actually designed a 
study' to look at the work of breath- 
ing when patients were breathing just 
through the endotracheal tube, not con- 
nected to the ventilator, and then we 
would do the same thing within 8 hours 
of their having a tracheotomy. We 
found that there is a tendency for tra- 
cheostomized patients (matched for 
the same size internal diameters) to 
have a lower respiratory rate, lower 
minute volume, and a slightly lower 
work of breathing per minute. Bro- 
chard's group has done a similar study 
that showed very similar things.^ We 
found that 4 patients ended up getting 
extubated in between dose times be- 
fore they could have a tracheotomy, 
and their work of breathing was very 
high — much higher than either through 
the trach or through the endotracheal 
tube. Maybe we should, as Dean (Hess) 
said earlier, just disconnect some of 
these patients from the ventilator but 
keep the orotracheal tube in, because 
the issue then isn't that the patient 
needs to be on the ventilator, it's that 

they need to have an airway. We've 
kind of come to the decision in the 
trauma ICU that the time to trach the 
patient is when they don't need to be 
on the ventilator anymore, but you 
can't remove the endotracheal tube. 


1 . Davis K Jr, Campbell RS Johnannigman JA, 
Valente JF, Branson RD. Changes in respi- 
ratory mechanics after tracheostomy. Arch 
Surg 1999;134(l):59-62.. 

2. Diehl JL, El Atrous S, Touchard D, Lemaire 
F, Brochard L. Changes in the work of breath- 
ing induced by tracheotomy in ventilator- 
dependent patients. Am J Respir Crit Care 
Med l999;159(2):383-388 

Heffner: Often in clinical investi- 
gation, we tend to use intermediary 
end points, such as airway resistance, 
and then attempt to determine whether 
an intervention such as tracheotomy 
is going to have an impact on the true 
outcome of interest, such as getting 
off the ventilator. Sometimes, despite 
the of good deductive reasoning, 
an intermediary end-point may not re- 
ally be a predictor of the ability to 
wean. So, it's hard to get around stud- 
ies that look at early tracheotomy in 
homogeneous groups of patients, such 
as trauma patients, and observe a 
shorter length of stay. We should crit- 
ically appraise those studies, and ask 
who is making the decision about 
transfer from the ICU. Were these cli- 
nicians aware of the intent of the study 
and of the tracheotomy? Generally, 
these studies are not adequately 
blinded. We should expect good ex- 
perimental designs from investigators 
who are doing studies that adminis- 
trators and HMOs (Health Mainte- 
nance Organizations) are going to read 
and use to tell us how to practice med- 
icine. It's very difficult to do those 
investigations, but without those data, 
I think we have to take a lot of these 
results with a grain of salt. 

Bishop: In a hospital that's not a 
Level One trauma facility, I might be 
more inclined toward an earlier tra- 
cheotomy. My recollection is that the 


Respiratory Care • July 1999 Vol 44 No 7 

Tracheotomy: Indications and Timing 

general consensus at the NAMDRC 
(National Association for Medical Di- 
rectors of Respiratory Care) was that 
this was not a procedure that should 
be done in acutely unstable patients. 
For the patient who is on 20 cm HjO 
of PEEP (positive end-expiratory pres- 
sure), the patient whose weight is up 
25 kilos, the patient who has multiple 
chest tubes, there probably is no ur- 
gency for a tracheotomy. It is really 
something for the long haul. Would 
you agree that the time to do it is not 
just when they're in for the long haul, 
but also when the patient is stable 
enough that they can be taken very 
safely to the operating room? 

Heffner: Yes, I would agree. 1 think 
that, from a decision analysis stand- 
point, we should emphasize the indi- 
vidualization of care. Ask yourself, 
what are the benefits I'm hoping to 
achieve with a tracheotomy? For me, 
it's usually simplification of care, de- 
crease of sedatives for a conscious pa- 
tient, increasing patient comfort, and 
enhancing patient mobility. When you 
have someone in the early phase of 
ARDS, receiving high PEEP, you're 
not going to reap those benefits with a 
tracheotomy. Early ARDS would max- 
imize the potential risks of tracheot- 
omy and limit the likelihood of ben- 
efit, which shifts you toward keeping 
the translaryngeal tube in place longer. 
Conversely, if you've got a conscious 
patient with a neuromuscular disor- 
der, such as myasthenia, who has pneu- 
monia and worsened neuromuscular 
capacity, that patient might benefit 
from a tracheostomy on the third day 
of hospitalization if you can predict 
that they're going to be on the venti- 
lator for 2-3 weeks. So, if that patient 
can benefit from the comfort advan- 
tages of a tracheotomy, you might de- 
cide to do it earlier in the course of 
disease than you would for the unsta- 
ble ARDS patient, everything else be- 
ing equal. 

Stoller: John, you've done your 
usual masterful job of defining this 

literature, and I think you've taken ev- 
idence-based medicine about as far as 
it can go in the context of this contro- 
versial subject. You outlined the cri- 
teria of a randomized trial, and con- 
cluded that, given the impossibility of 
conducting such a trial, we are rele- 
gated to the next best observational 
data of meta-analysis and evidence- 
based medicine. However, we also live 
in the era of the NEXT (The National 
Emphysema Treatment Trial) trial and 
the OBEST (The Overholt-Blue Cross 
Emphysema Surgery Trial) trial, 
which are multicenter and, atypically, 
funded by insurers, including HCFA 
(Health Care Financing Administra- 
tion), Blue Cross/Blue Shield of Mas- 
sachusetts, and consortia of other in- 
surers who stand to benefit. Given 
these novel funding strategies for im- 
portant randomized trials, can you 
imagine conducting a multicenter ran- 
domized trial of tracheotomy interven- 
tion at the time intervals you outlined? 
We confront this issue in so many dif- 
ferent arenas, and I think that in the 
era of evidence-based medicine, we're 
quick to conclude that randomized tri- 
als are impossible because they're hard 
and expensive. But I' ve started to think 
that perhaps the eggshell is breaking a 
little bit about the seeming impossi- 
bility of randomized trials. Maybe 
we're too quick to conclude that these 
things can't be done. 

Heffner: I'd like to see such a tra- 
cheotomy study done, and even per- 
haps with limited scope with 3 or 4 of 
those patient subgroups that we have 
listed up there in high-volume centers 
that are known for the excellence of 
their respiratory therapy in their ICUs 
and the excellence of their surgical 
technique, so we can control for co- 
variants. I think that certainly is pos- 
sible, but so far there hasn't been a lot 
of energy surfacing to rigorously in- 
vestigate tracheotomy. I worry that 
when we do rigorous studies we will 
come up with the "efficacy" of the 
intervention. "Efficacy" describes 
what works in a research setting. In 

these best practice centers, we can 
learn the correct decision-making, but 
what we talked about in this confer- 
ence is the "effectiveness" of what we 
do. "Effectiveness" pertains to what 
works in real world settings. We need 
to ask if the research results from best 
practices centers are applicable to the 
community hospitals, where most pa- 
tient care occurs in this country. I agree 
that multicenter, randomized, con- 
trolled trials are best, and if we can 
get the energy and support to do such 
studies, then we should, but we're still 
challenged to determine how general- 
izable the results are going to be. 

Stauffer: I would echo that com- 
ment. I think such a study is feasible 
and certainly desirable. The question 
is whether the findings would be 
widely applicable. What we are fac- 
ing is a vastly different tracheotomy 
complication rate between trainees in 
fairly unsupervised settings and expe- 
rienced surgeons who have done this 
operation many times and take a per- 
sonal interest in the outcome of the 
patient. The complication rate of tra- 
cheotomy is so variable from report to 
report and institution to institution that 
it may reflect the personal interest and 
the skill of the surgeon. When this 
operation is done by second-year res- 
idents who are pretty much on their 
own, I think you're going to see high 
complication rates, such as we ob- 
served 20 years ago.' I have another 
comment in regard to an earlier sub- 
ject — the issue of removing a trache- 
ostomy tube once it's in. I think phy- 
sicians, by nature, are eager to extubate 
patients as soon as possible. I don't 
find everyone interested in decannu- 
lating patients as soon as possible. 
There .seems to be some inertia to leave 
tracheostomy tubes in place. 


1 . Stauffer JL. Olson DE, Petty TL. Compli- 
cations and con.sequences of endotracheal 
intubation and tracheotomy: a prospective 
study of 150 critically ill adult patients. 
Am J Med l981;70(l):6.S-76. 

Respiratory Care • July 1999 Vol 44 No 7 


Tracheotomy: Indications and Timing 

Heffner: I think that's a good point. 
I've learned a lot from respiratory ther- 
apists in my career, and one of the 
things I learned in a stint in private 
practice with a superb group of respi- 
ratory therapists in Colorado Springs 
was their approach to getting the trach 
tube out as early as possible. They 
were very aggressive. They used a lot 
of tracheostomy buttons, to be able to 
accelerate weaning. Trach buttons al- 
low airway decannulation while re- 
taining the option of putting the trach 
tube back in. This approach acceler- 
ates getting the tube out quickly. 
There's pretty good literature on how 
to do that, but it doesn't exist in our 
usual academic, high-end journals. 

Bishop: John, as you've gone over 
the literature, what do you think about 
the conjecture that tracheotomy fol- 
lowing prolonged intubation actually 
increases the risk of laryngeal steno- 
sis? That' s a criticism that' s been made 
of Whited's cases of stenosis.' Per- 
haps what he actually demonstrated is 
that a tracheostomy following pro- 
longed intubation results in stenosis. 


1 . Whited R. A prospective study of laryn- 
gotracheal sequelae in long-term intuba- 
tion. Laryngoscope 1984;94(3);367-377. 

Heffner: There's a concern that the 
longer you leave the translaryngeal 
tube in, the more you damage the lar- 
ynx, which is the first insult to the 
airway, and then if you put the trach 
tube in, you may allow suppuration of 
the airway to reflux proximally into 
this denuded mucosa, which represents 
the second insult. That argument cuts 
both ways. It could be an argument 
against doing the tracheotomy, or it 
could be an argument to do the tra- 
cheotomy earlier, before that first in- 
jury occurs. Clarence Sasaki used an 
animal model to study contamination 
of the laryngeal region of the airway 
caused by tracheotomy, and found that 
there was increased colonization and 

damage to the mucosa.' As far as I 
know, this finding has never been dem- 
onstrated in humans. We did a study 
that we haven't published yet, where 
we bronchoscoped intubated patients 
and sampled the endolarynx, pre-trach 
and then post-trach, with quantitative 
culture techniques. We were unable to 
find any contamination of the subglot- 
tic region after tracheotomy, or in- 
crease in colonization. The subglottic 
regions are already so colonized and 
contaminated that we couldn't iden- 
tify any increase in concentration of 


1. Sasaki CT. Horiuchi M. Koss N. Trache- 
ostomy-related subglottic stenosis: bacte- 
riologic pathogens. Laryngoscope 1979; 
89(6 Pt l):857-865. 

Bishop: I thought Gene Colice' s pa- 
per' suggested that patients who had a 
tracheotomy after intubation ended up 
with more laryngeal problems. 


1. Colice GL. Resolution of laryngeal injury 
following translaryngeal intubation. Am 
RevRespirDis l992;145(2Pt l):.%l-364. 

Heffner: Yes, but again, it wasn't 
randomized. It was an observational 
study, which tends to bias the sicker 
patients into the tracheotomy arm. This 
issue is a causation question, and we 
can't answer causation questions by 
observational studies. 

Reibel: This concern has been 
around a long time, and 1 don't see it 
substantiated. I think the thing that's 
underappreciated is the importance of 
reflux of acid peptic .secretions up onto 
this denuded mucosa. Gastroesphageal 
reflux and laryngopharyngeal reflux 
is a hot topic now. We haven't really 
done a good job of looking at that, but 
1 think that when we do, it will start to 
be a significant predictor of posterior 

glottic pathology. It's difficult to use 
proton pump inhibition, because you 
can't give it intravenously in an easily 
accessible form, and it's tough to put 
down a tube. Hj blockade and promo- 
tility agents don't achieve the same 

Heffner: So, that may be another 
reason to elevate the head in intubated 
patients, or undergo tracheotomy. 

Watson: Over the years that I've 
watched this literature, I've found it 
very depressing, mostly because what 
you have is groups of individuals who 
compare their best practice with some- 
body else's worst practice and then 
draw emotional conclusions. This is 
largely because needed studies have 
not yet been done. It seems to me that 
this practice is sort of a self-guided 
thing; that is, it grows and changes by 
itself, almost in isolation from the ac- 
ademic literature, given the flaws in 
the academic literature. I'm curious to 
know what the implication of percu- 
taneous tracheostomy would be. I've 
certainly seen that in the region where 
I work, laryngologists are almost never 
doing tracheostomies anymore. It's ex- 
traordinary to go to the operating room. 
This is a very low morbidity picture. 
I'm curious to know whether you have 
any thoughts about where we're go- 
ing with that. Will we be doing more 
trachs because it's viewed as easier 
somehow and less frightening? Or will 
we be doing the same number? Will 
we be doing them sooner? 

Heffner: I've been trying to observe 
that in ICUs around the country where 
there is a nonsurgeon intensivist re- 
sponsible for the patients who has 
learned how to do that procedure. And, 
it seems like the outcomes are varied. 
I made rounds in one ICU where prob- 
ably 80% of the ventilator patients had 
a tracheotomy. Tracheotomy was al- 
ways done in the first 3 days in this 
major academic institution. The inten- 
sivist had learned the procedure and 

Respiratory Care • July 1999 Vol 44 No 7 

Tracheotomy: Indications and Timing 

made the patient-centered decision, 
"This is good for my patients, I've 
noticed that they do better with a tra- 
cheotomy, I don"t have to wait for op- 
erating room time, and I can do the 
procedure myself." Other medical in- 
tensivists have learned how to do the 
procedure, but have not expanded their 
use of tracheotomy in their ICU. In 
these ICUs, learning percutaneous tra- 
cheostomy has simplified the chain of 
events to getting the trach done, but 
hasn't changed physicians' beliefs re- 
garding the value of tracheotomy. Cost 
and simplicity of doing a procedure 
do factor into decision-making, so tra- 
cheotomy could be employed more of- 
ten if we cut out some of the hurdles 
and expense of having the procedure 

Stoller: I'd like to revisit the dis- 
cussion about randomized trials and 
the distinction between efficacy and 
effectiveness. I think it is important 
that the need to understand effective- 
ness not pre-empt our interest in de- 
termining efficacy. Perhaps studies 
that establish efficacy can be the 
springboard for understanding varia- 
tions in practice that impact effective- 
ness. In fact, I think it would prompt 
even more interest in performing ef- 
ficacy studies so that we can under- 
stand deviations caused by local prac- 

tice variations that would define the 
reasons for lack of effectiveness when 
the maneuver is efficacious. 

Heffner: I agree, and would pro- 
mote randomized, controlled trials in 
every question in medicine. But this 
issue has been around for a long time, 
and so far we haven't seen the energy 
or funding emerge to really get ran- 
domized trials done. I think Mike 
Bishop, Gene Colice, and I met 10 
years ago and discussed the reason- 
ableness of doing a multicenter trial, 
at least between the 3 of us, who were 
interested in airway management. We 
didn't have the support or resources 
to get it done. I think we can now 
possibly look to the AHCPR (Agency 
for Health Care Policy and Research) 
for funding, since they are interested 
in examining best clinical practices. 
Perhaps they can help prioritize im- 
portant topics in clinical medicine that 
impact sufficiently society to justify 
funding of randomized, control trials. 
That's a course we should perhaps ac- 
cept as a responsibility to follow after 
this conference. 

Thompson: I would urge anyone 
who conducts such a study to exam- 
ine who does the procedure, what their 
training has been, and who's super- 

vising them. Outcomes are likely to 
vary with the experience of the oper- 
ator and the degree of independence 
permitted. Otherwise, in effect, we 
may be comparing the results of jun- 
ior house staff to those of senior fac- 
ulty, rather than the safety and effi- 
cacy of 2 procedures. 

Heffner: I think we have sufficient 
understanding of the procedure and the 
results of timing at different points of 
care, the outcomes of interests we 
should observe, and the factors that 
dictate success from a technical stand- 
point. For most medical centers and 
hospitals (community or academic), 
the most important task is to organize 
a group of interested, multidisciplinary 
people to come up with a guideline or 
practice protocol. The exact elements 
of the protocol are perhaps less im- 
portant than having a protocol in place 
that can then be monitored and ad- 
justed on the basis of monitored re- 
sults. This allows development in your 
practice domain of best practices. Why 
some centers have a Mike Bishop who 
promotes best practices in airway man- 
agement and other centers don't is un- 
clear. Physicians and nonphysician 
champions emerge in some medical 
centers to drive the culture toward con- 
tinuous improvement. 

Respiratory Care • July 1999 Vol 44 No 7 

Tracheotomy A'racheostomy 

James F Reibel MD 


Surgical (Open) Tracheostomy 

Percutaneous Dilational Tracheotomy 


[Respir Care 1999;44(7):820-823] Key words: 
percutaneous dilational tracheotomy. 

tracheotomy, tracheostomy. 


Tracheotomy is a mainstay in the airway management 
of critically ill patients, providing access for mechanical 
ventilation, clearance of secretions, and protection of the 
airway. This procedure has often been performed in the 
operating room (OR), by preference of the surgical team. 
Bedside tracheotomy has been done reluctantly, despite 
evidence that the procedure can be done safely and cost- 
efficiently at the bedside,' eliminating the risks involved 
with patient transport. ^ The development of percutane- 
ous dilational tracheotomy (PDT)^ has allowed trache- 
otomy to be safely conducted by both surgeons and 
nonsurgeons. Experience with PDT has shown that many 
patients can be safely tracheotomized in the intensive 
care unit (ICU), thereby eliminating risks of transport, 
easing scheduling difficulties, and providing significant 
cost savings. These developments have catalyzed dis- 
cussion of the "how" and "where" of performing tra- 

Surgical (Open) Tracheostomy 

Surgical tracheotomy or tracheostomy can be safely per- 
formed at the bedside,' but surgeons prefer to perform the 
procedure in the operating room, where the lighting is 
better, there is a full complement of assistants available, 
and the ergonomics of the operating table are more favor- 

James F Reibel MD is affiliated with the Department of Otolaryngology. 
Head and Neck Surgery, University of Virginia Medical Center. Char- 
lottesville. Virginia. 

Correspondence: James F Reibel MD. Department of Otolaryngology, 
Head and Neck Surgery. University of Virginia Medical Center. Char- 
lottesville VA 22908. E-mail: 

able. The lack of these favorable factors should indeed 
lead to the performance of a technically difficult open 
procedure in the OR if it is in the patient's best interest. 
Nevertheless, evidence that bedside tracheotomy or tra- 
cheostomy can be accomplished at less cost, without need 
for patient transport, and with low complication rates should 
lead to an increase in tracheostomies performed in the 
ICU.' Surgeons are slowly being persuaded and are seek- 
ing to improve the ergonomics of the ICU .setting for this 

Tracheotomy refers to an opening made in the trachea 
without connection to the skin surface. Tracheostomy 
refers to a tracheal opening with a surgical attachment 
to the skin. Patient safety is enhanced when tracheos- 
tomy is performed. The attachment to the skin facili- 
tates identification of the tract and prompt reinsertion of 
the tracheal cannula if the patient should accidentally 
become decannulated. The modification of the Bjork 
flap^ (as advocated by Dukes'" and Chew^) provides a 
secure attachment of trachea to skin (Fig. 1). Creation 
of the tracheal flap and tract does not add significant 
technical difficulty or increase the incidence of stenosis, 
and the tract facilitates transfer from endotracheal tube 
to tracheostomy tube. In patients with short, thick necks, 
where a tracheal flap might not reach the skin, a mod- 
ification of the "omega" skin flap technique might be 
necessary to provide this secure tract.'* Since a selection 
bias for use of the open technique in the more difficult 
cases is already becoming apparent, the tracheostomy 
procedure provides an extra measure of safety. 

Percutaneous Dilational Tracheotomy 

Development of the PDT technique in 1985 provided 
surgeons and non-surgeons with a significant new option 
in securing the airway.^ Numerous studies have indicated 


Respiratory Care • July 1999 Vol 44 No 7 


Fig. 1. A: Tracheal exposure prior to flap creation. Cricoid hook (short arrow) holds cricoid cartilage and elevates trachea into the wound. 
Second tracheal interspace (long arrow) is superior limit of the modified "Bjork" flap. B: Cricoid hook continues to elevate trachea in 
preparation for insertion of tracheotomy tube. Suture (arrow) secures trachea to skin margin. 

that PDT is re-producible with complication rates usually 
lower than open tracheotomy.''-'-* These studies also dem- 
onstrate that PDT can be performed safely and expedi- 
tiously'"'-''' at the bedside without the risk and cost of 
transportation to the OR.'"'--'* 

Until a physician has had significant experience with 
this technique, strict selection criteria should be utilized 
(Table 1 ). As one becomes more experienced with PDT, 
it can be applied in more difficult situations. '"'^ Diffi- 
cult reintubation if the airway is lost during PDT should 
prompt a decision for an open procedure. " • ' - With proper 
patient selection, PDT can be safely performed, and 
the advantages of enhanced patient care at lower cost 

The Seldinger technique concept is familiar to all who 
work in the ICU environment. While the technique is 

Table 1 . Selection Criteria for Percutaneous Dilational Tracheotomy 


• Easy reintubation (A) 

• No coagulopathy (R) 

• Adult (R) 

• Favorable neck anatomy (R) 

• Good extension 

• Thin 

• No goiter 

• No prior anterior surgery 


• Difficult reintubation (A) 

• Coagulopathy (A) 

• Unfavorable anatomy (R) 

■ absolute indication, R - relative indication. 

Straightforward, appropriate attention to detail in execu- 
tion will facilitate an expeditious procedure with minimal 
complications. The patient is positioned with the neck ex- 
tended, and the skin in the area of puncture and incision is 
infiltrated with local anesthetic with epinephrine from the 
kit (Fig. 2). Some additional topical anesthetic can be in- 
stilled into the trachea via the endotracheal tube as well. 
Physiologic monitors are checked frequently as the patient 
is appropriately sedated and paralyzed as required. Flex- 
ible fiberoptic guidance is not required,'"'- but its use 
does confirm proper midline introduction of the needle 
and guide wire without cartilaginous injury and helps 
prevent paratracheal insertion of the dilators and inad- 
vertent injury of the membranous trachea'""''* (Fig. 
3). When using bronchoscopic guidance, an end-tidal 
carbon dioxide monitor is advisable''-''* to avoid hyper- 
carbia, especially with head injury patients. Once the 
tracheotomy tube is in place, it should be sutured to the 
skin and secured with a twill tape tied snugly around the 

The most significant perioperative risk for a patient un- 
dergoing PDT is accidental decannulation. This complica- 
tion must be addressed with the ICU staff in advance. Prior 
to 2 weeks, a mature tract has not formed, and attempted 
reinsertion of the tracheotomy tube can lead to bleeding, 
tracheal injury, and death. The patient suffering accidental 
decannulation should be reintubated orally and the airway 
controlled. Once the airway is controlled, the tract can be 
explored, allowing replacement of the guide wire and di- 

Respiratory Care • July 1999 Vol 44 No 7 



SIMS, Inc. 

Ktt-ric, NH a543l U.S.A. 


CAT. NO. 511070 

TUBE ID 7.(Wi 


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■ SEE iMS»ii arcti rnowKQ 'on ■iMn«n 

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Fig. 2. One of the commercially available PDT kits. A: List of in- 
cluded components. B: Components in package. 

lators, with successful reinsertion of the tracheotomy tube.* 
This protocol should be reinforced frequendy to ensure 
that all members of the ICU staff are aware of the risks 
inherent in the misguided attempt to reinsert the tracheot- 
omy tube. 

Properly done, PDT has been shown to be a safe and 
cost-effective procedure. Pneumothorax has been reported 
in 0-10% of surgical/open procedures, while the incidence 
of pneumothorax with PDT is 0.4-6.4%.'^'o"'4 Bleeding 
complication rates of 1.2-3.2%9"'i '-'^ with PDT compare 
favorably with the widely varying bleeding complication 
rates of 1-37% reported with open procedures."''* Steno- 
sis has been acceptably low (0.8-2.3%)'''"''* compared to 
surgical tracheostomy (0.5%).''* The cost savings of 
$ 1 ,300-$l ,900,'0'2-"* and the significantly more rapid pro- 
cedure time of PDT'""''* would mean little without such 
evidence of safety and reproducibility. 


Tracheotomy and tracheostomy are procedures that pro- 
vide airway access for continued mechanical ventilation 

and pulmonary toilet in critically ill patients. The devel- 
opment and refinement of PDT'-' has added a capability 
that allows patients to be treated safely and expeditiously 
at cost savings. While applicable to many, if not most 
patients, not all should be considered for this technique. 
Patients with difficult anatomy, either at the procedure site 
or of the upper airway precluding expeditious oral intuba- 
tion, especially those with upper airway obstruction, should 
have open surgical tracheostomy. The open technique 
should be utilized in the ICU setting more frequently, 
thereby reserving transportation to the OR for those who 
require it. Only in an environment of collaboration and 
cooperation will such an efficient approach flourish; how- 
ever, improved patient outcomes, reduced direct patient 
costs, and enhanced efficiency of OR utilization are pow- 
erful incentives. 


1. Wease GL, Frikker M, Villalba M, Glover J. Bedside tra- 
cheostomy in the intensive care unit. Arch Surg 1996; 1.31 (5):552- 

2. Indeck M, Peterson S, Smith J. Brotman S. Risk, cost and benefit of 
transporting ICU patients for special studies. J Trauma 1988:28(7): 

3. Ciaglia P, Firsching R, Syniec C. Elective percutaneous dilatational 
tracheotomy. A simple bedside procedure: preliminary report. Chest 

4. Sokolov M, Roth Y, Harell M. Improved ergonomics for bedside 
trachecstomy. Laryngoscope l998;108(6):944-945. 

5. Bjork VO. Partial resection of the only remaining lung with 
the aid of respirator treatment. J Thor Cardiovasc Surg 1960; 

6. Dukes HM. Tracheostomy. Thorax 1970;25(5):573-576. 

7. Chew JY, Cantrell RW. Tracheostomy. Complications and their man- 
agement (review). Arch Otolaryngol 1972;96(6):538-545. 

8. Eliachar I, Stegmoyer RJ, Levine HL, Sivak ED, Mehta AC, Tucker 
HM. Planning and management of long-standing tracheostomy. Oto- 
laryngol Head Neck Surg 1987;97(4):385-390. 

9. Marx WH, Ciaglia P, Graniero KD. Some important details in the 
technique of percutaneous dilatational tracheostomy via the modified 
Seldinger technique. Chest 1996:1 10(3):762-766. 

10. Hill BB, Zweng TN, Maley RH, WE, Toursarkissian B, 
Kearney PA. Percutaneous dilational tracheostomy: report of 356 
cases. J Trauma 1996;41(2):238-243. 

1 1 . Graham JS, Mulloy RH, Sutherland FR, Rose S. Percutaneous versus 
open tracheostomy: a retrospective cohort outcomes study. J Trauma 

12. Cobean R, Beals M, Moss C, Bredenberg CE. Percutaneous dilata- 
tional tracheostomy: a safe cost-effective bedside procedure. Arch 
Surg I996;131(3):265-27I. 

13. Fernandez L, Norwood S, Roettger R. Gass D, Wilkins H 3rd. Bed- 
side percutaneous tracheostomy with bronchoscopic guidance in crit- 
ically ill patients. Arch Surg 1996;131(2):129-132. 

14. Powell DM, Price PD. Forrest LA. Review of percutaneous trache- 
ostomy. Laryngoscope 1998;108(2):170-177. 


Respiratory Care • July 1999 Vol 44 No 7 


..: Hbt: 

ii 16 961 

.-,-1 1 .qo 


Fig. 3. Percutaneous dilational tracheotomy being performed with bronchoscopic guidance. A: Placement of guide wire and dilator. B: 
Progressive dilation. C: Bronchoscope view showing approphate placement and no cartilage injury. D: Insertion of the tracheotomy tube. 

Respiratory Care • July 1999 Vol 44 No 7 




Heffner: One of the problems with 
doing a PDT is impaling the endotra- 
cheal tube. Pulling the endotracheal 
tube back during a difficult procedure 
risks hypoventilation. A neat innova- 
tion I saw presented from the Sloan- 
Kettering group was the use of an ex- 
tubation laryngeal mask airway 
(LMA) during PDT. I was wondering 
if you've had experience with that, or 
can comment. Is that something we 
should do? 

Reibel: We do it with a fiberoptic 
scope through the endotracheal tube. 
That way, we know we're at the right 
spot; we can see where the needle pen- 
etrates the trachea; we can count the 
rings. If we happen to back the tube 
out too far, the scope is in the way, 
allowing easy reintubation. When you 
lose the advantage of the broncho- 
scopic guidance, you can't ensure that 
you have a sagittal introduction, and 
you can't ensure that you're not com- 
ing through cartilage in the process. 
Avoiding injury to the cartilage is 
absolutely key. We think we can 
minimize stenosis complications if we 
take great care to avoid injuring the 

Durbin: I can comment on the use 
of the LMA in PDT. I presented an 
abstract at the American Association 
for Respiratory Care meeting report- 
ing the first 7 patients that we've done 
with an LMA. ' It' s a very elegant tech- 
nique in a patient who is breathing 
spontaneously. If needed, you can give 
positive pressure with the LMA. The 
advantage of the LMA is that you can 
accurately identify the tracheal rings 
and avoid the cricoid ring because the 
endotracheal tube is no longer in the 
way. It works very nicely. The neu- 
rosurgical patients are ideal because 
they already have diminished airway 
reflexes. What I've found is that if 
you have to extubate the patient to use 
the LMA, some of these patients de- 
velop stridor and require reintubation 

for airway control. I've done this 4 or 
5 times, and it turns a 10-minute pro- 
cedure into a 1-hour procedure, so I 
am no longer electively extubating pa- 
tients at the time I'm doing a PDT. I'll 
extubate them an hour ahead, come 
back, and if they're okay, then use the 
LMA. I do really like using the LMA, 
because it protects the bronchoscope 
from the needle. If the needle dam- 
ages the bronchoscope, that's a $5,000 
mistake. After topical anesthesia and 
a transtracheal local injection, I place 
the LMA with the patient under light 
sedation. The LMA is usually directly 
in front of the larynx, so you can eas- 
ily see the laryngeal anatomy and as- 
sess how much damage prolonged in- 
tubation has caused. You can quickly 
intubate through the LMA with the fi- 
beroptic scope if you have an endotra- 
cheal tube threaded on it ready to go. 


1. Durbin CG Jr, Seay W. Use of the laryn- 
geal mask airway (LMA) during perfor- 
mance of percutaneous, bedside tracheot- 
omy (abstract). Respir Care 1998;43(10): 

Watson: I would comment that I 
actually don't do percutaneous trache- 
otomies, though I assist with them 
from time to time. We began doing 
them all bronchoscopically, and we 
went through this process with how 
far back do you pull the tube to get it 
out of the way (which was problem- 
atic in our institution because the habit 
had been to have the tube too far down), 
cut down, open the trachea over the 
tube, and then pull the tube back so 
that one would insert the tracheostomy 
tube, whether we did a flap or not. 
People do the same technique in dif- 
ferent ways. A modification that I've 
used on occasions when 1 ' ve been wor- 
ried about difficulty of reintubation is 
to put a pediatric airway exchange 
catheter down. That leaves me with a 
sense of security, with oxygen flow- 
ing into the trachea. Whatever upper 
airway maneuver I do, typically the 
breathing tube adjusts very far back in 

the larynx, and the scope is kept well 
above the puncture site, so that when 
I see the guide wire and we start di- 
lating, I pull the small airway exchange 
catheter out. I'd be surprised to see 
that many people were doing this in 
the patients who were worrisome from 
the standpoint of intubation. 

Bishop: We don't do percutaneous 
PDTs in our hospital. I see significant 
political battles that would arise. Cer- 
tainly one potential pitfall that I'd be 
concerned about, and would like to 
hear your opinion on, is that if you 
have nonsurgeons doing these, how 
do surgeons feel about potentially be- 
ing called upon to take care of some- 
body else's complications? 

Reibel: Obviously, our residents 
aren't crazy about it, but that has not 
been a problem. Jon Truwit told me 
that he's occasionally had a little bit 
of nuisance bleeding as he's intro- 
duced one of the dilating catheters. 
He just holds pressure on it to tam- 
ponade it, and he's never had to abort. 
We don't want to take a case that has 
a precarious airv/ay and lose that air- 
way. If you have a that you know 
is a difficult reintubation, and you get 
a little bit of bleeding, I would back 
out and not persist. Surgeons are al- 
ways relatively quickly available to 
come and bail you out if you get into 
trouble. The issue of turf battles — this 
is something we're going to have to 
be adult about and work through. 
We're going to have to do what's best 
for both the patient and the institution, 
collectively. If we can have patients 
get done expeditiously without in- 
creased complications and at a cost 
savings, we're going to have better 
outcomes. We're going to have less of 
a headache for our OR directors and 
fewer nurses quitting because of fre- 
quently having to stay an extra 2 or 3 
hours to get the elective surgery done. 
So, admittedly, there are going to be 
turf battles. But, at the end of the day 
we're going to have to be adults and 
work through it. 


Respiratory Care • July 1999 Vol 44 No 7 


Durbin: I'd like to compliment Jim 
(Reibel) on how easily this has gone 
in our own institution. Jon Truwit is a 
pulmonologist, head of the medical 
ICU. At his first 10 or so procedures 
he had an anesthesiologist and an ear- 
nose-throat surgeon with him when he 
did the procedure. It was a collabora- 
tive team learning the process. Now 
it's being endorsed by all 3 services 
and general surgery. In fact, the ear- 
nose-throat residents are often doing 
the procedure with me to get their ex- 
perience as well. It's been a collabo- 
rative process to introduce the right 
technique for the group of patients who 
will benefit from it. Maybe there's 
some competition, but it's minimal. I 
think everybody agrees that it's to the 
institutional advantage to do PDTs on 
appropriate individuals. It's also ap- 
propriate to have backup from all ser- 
vices if the need arises. 

Stauffer: I guess I'm going to be 
somewhat of a skeptic here, because, 
at last count, I think we only had 4 
randomized, prospective clinical trials 
of PDT versus standard tracheoto- 
my,' -^ and in 1 of those 4 trials. I 
believe, the percutaneous technique 
was done in the operating room.'* In 2 
of the studies,--* it was done under 
general anesthesia. Only 1 of the stud- 
ies addressed long-term complications 
of PDT.' One nonrandomized study 
did look at some of the long-term com- 
plications of PDT.'' I would echo a 
concern that John Heffner raised in an 
editorial'' in 1991, that we need more 
information about PDT before we to- 
tally embrace it. Another comment is 
that in some of the cost or charge anal- 
yses that have been published, the au- 
thors did not include the cost of the 
bronchoscopy procedure (hospital 
charge and professional charge). I 
think when you add that in. and when 
you consider that standard tracheot- 
omy can be done at the bedside, sav- 
ing the OR costs, the costs of PDT 
and standard tracheotomy are actually 
somewhat similar. 


1 . Hazard P. Jones C. Benitone J. Comparative 
clinical trial of standard operative tracheos- 
tomy with percutaneous tracheostomy. Crit 
Care Med I991;19(8):I018-1024. 

2. Crofts SL, Alzeer A, McGuire GP, Wong 
DT, Charles D. A comparison of percutane- 
ous and operative tracheostomies in inten- 
sive care patients. Can J Anaesth 1 995;42(9): 

3. Friedman Y. Fildes J, Mizock B. Samuel J, 
Patel S. Appavu S. Roberts R. Comparison 
of percutaneous and surgical tracheostomies. 
Chest 1996;110(2):480-485. 

4. Holdgaard HO. Pedersen J. Jensen RH, Out- 
zen KE. Midtgaard T. Johansen LV, et al. 
Percutaneous dilatational tracheostomy ver- 
sus conventional surgical tracheostomy: a 
clinical randomized study. Acta Anaesthe- 
siol Scand 1998;42(.5);545-550. 

5. van Heurn LW, Goei R, de Ploeg I, Ramsay 
G, Brink PR. Late complications of percu- 
taneous dilatational tracheotomy. Chest 

6. Heffner JE. Percutaneous tracheotomy: novel 
technique or technical novelty? (editorial). 
Intensive Care Med 1991;17(5):252-253. 

Reibel: About the .second issue, I 
agree. There is no reason that we can't 
do open procedures at the bedside. In 
regard to the cost issue for the flexible 
scope, from time to time we will use 
one of our flexible scopes and won't 
charge the patient. If we are under time 
pressure occasionally, we will get the 
bronch cart, and then the patient is 
charged. I believe the institution does 
generate an extra charge for that. We do 
not charge for bronchoscopy, but there 
is an institutional charge for the use of 
the scope. The Olympus ENFP scope 
will fit in an appropriately trimmed en- 
dotracheal tube easily, and we've got 
those readily available in the clinic. 

Hurford: One of the things to re- 
member when you're looking at costs 
is that what the hospital can charge as 
an institutional charge is, of course, 
irrelevant to the actual cost of the pro- 
cedure to the hospital. What you need 
to look at is the marginal costs of la- 
bor, personnel, and replaceable equip- 
ment that the hospital incurs when 
comparing a tracheostomy done in the 
OR with one done in the ICU. We 
have extremely limited experience 

with PDT at our hospital, and the ex- 
perience that we have is skewed in 
that most of the patients we have seen 
have been referred for repair of tra- 
cheal or cricoid damage. One of the 
most common things we've seen has 
been cricoid injury from the PDT be- 
ing done too high. It's not unusual 
that the PDT has actually been a cri- 
coidthyrotomy rather than a tracheos- 
tomy. Is that just a very unusual 
skewed view, or does bronchoscopy 
really help compared to doing it with- 
out bronchoscopy? 

Reibel: I think it helps. Everybody 
wants to adopt this new technique. It's 
like the situation after the advent of 
the CO2 laser: everybody wanted to 
use it. It is the same with PDT — it has 
its place. You need to have anatomy 
that you can easily localize by palpa- 
tion. If you can feel the cricoid, you 
shouldn't impale it with the introducer 
and dilators. If you can feel it and you 
can have visual confirmation of the 
sagittal introduction into the trachea, 
not injuring cartilage, I think that's 
the best you can do with this tech- 
nique. I think it's up to us to make 
sure this technique is used appropri- 
ately and properly. I think this venue 
is appropriate to get the word out. 

Thompson: Yesterday, you asked 
me if we were doing PDTs on the ad- 
olescents, and the answer was no. Do 
you know whether people have begun 
to lower the age threshold anywhere? 

Reibel: I have no firsthand infor- 
mation, but I'd bet on it. Because peo- 
ple want to be the first to push the 
envelope. They are going to want to 
extend the indications for this. I think 
it's appropriate for us to say do it at 
your own risk. I certainly don't think 
it's appropriate to take it below 14, 
15, 16. I've seen all 3 of those ages in 
the literature, but we have not done it 
on anyone who is not of legal age. 

Durbin: I've done it on a 16-year- 

Respiratory Care • July 1999 Vol 44 No 7 



Reibel: How was it? 

Durbin: It was a big 16-year-old, 
bigger than me. It went fine. 

Watson: PDT is not that new a pro- 
cedure. In the mid- to late- 1960s, a 
neurosurgical group in Philadelphia 
did work with the Seldinger technique 
for placing standard tracheostomy 
tubes: they published and actually mar- 
keted their stuff. What's going on at 
this point is that we have a company 
that began selling bronchoscopy- 
assisted PDT and training people all 
over the country, and now we're see- 
ing an explosion of interest. I think 
the reason the interest and the sales 
are coupling with growth of utiliza- 
tion is that it's just much more con- 
venient and that does play a role. 
Sooner or later, even in Boston, how 
much it costs will become very im- 
portant, because it will come out of 
the pockets of the people in the Bos- 
ton system who are supporting it, no 
matter what the fixed rate may be. This 
still suffers from the problem that all 
of the airway literature has, which is 
that each paper looks at a specific way 
of doing something, and there's wide 
variability around the world in percu- 
taneous dilatational tracheotomy; 
many people do a cut-down to the tra- 
chea, and then they know where 
they're putting the needle. There are 
horrible complications published by 
people who are doing blind sticks at 
the trachea, and then there are the peo- 
ple who do use the bronchoscope and 
those who don't. In our institution, the 
trauma surgeons stopped using the 
bronchoscope after about 30 cases, and 
we have yet to have any complica- 
tions without bronchoscopy. I think it 
was a reassurance issue, but we don't 
have and probably won't get data that 
compare apples with apples, because 
of this variability, because it's so con- 
venient, it's cheaper, and it .seems to 
not be associated with great compli- 
cation rates overall. 

Campbell: This spring, we were at 
the Brussels critical care meeting, and 
there was a great debate about the dif- 
ferences between different manufac- 
turers and different techniques. I'm 
wondering how you or someone at 
your hospital did the evaluation, and 
have they changed some of those? Are 
there still differences based on the 
equipment that's available? And what 
are they? 

Reibel: I don't want to advocate any- 
body's equipment. 1 think people have 
to evaluate the equipment on their own 
and find out what works at their insti- 
tution. This has to be agreed to by the 
intensivists and surgeons who collab- 
orate on this, because the hospital will 
not stock different commercial kits. 

Durbin: I can comment on this is- 
sue. There are basically 2 kits avail- 
able. There's a kit by Ciaglia and one 
by Portex. The Ciaglia kit does not 
come with its own tracheostomy tube. 
You have to add the tube to the kit. 
This is a major disadvantage because 
the added tube doesn't fit on the dila- 
tors quite as snugly, so introducing it 
is more difficult. The Shiley-Portex 
device has a snug-fitting tube with a 
small cuff that goes in a lot easier. 
We've opted for this kit in our insti- 
tution, although I have to tell you I've 
now done 50 of them, and I don't like 
the tube cuff very much. It's a thin, 
high-pressure cuff, and it's gotten me 
into trouble a couple of times. I've 
had to change several tubes early be- 
cause of it. I'm thinking now maybe 
the Ciaglia kit is the right idea, where 
you can use whatever tube you wish. 

Pierson: 1 would like to discuss the 
correct use of the words tracheotomy 
and tracheostomy. I wonder if all of 
us here could agree on definitions for 
those words. 1 regard tracheotomy, by 
analogy to laparotomy, as a surgical 
procedure, whereas tracheostomy, by 
analogy to colostomy, is the opening 
that is made. Therefore, the tube you 
put into it is a tracheostomy tube. 

Reibel: A tracheotomy is an open- 
ing in the trachea. A tracheostomy is 
an opening in the trachea with a direct 
connection to the skin. A PDT does 
not initially create a tracheostomy be- 
cause there is no connection with the 
skin. For surgical tracheostomy to be 
100% correct, we would have to su- 
ture the skin edge 360 degrees around 
the tracheal opening. For the purposes 
of safety, a secure inferior attachment, 
as with the Duke's modification of the 
Bjork flap, provides a secure connec- 
tion between skin and the tracheal mar- 
gin that will prevent loss of the tra- 
cheotomized airway. 

Pierson:* Is that usage also em- 
ployed? In other words, are there other 
usages as well? 

Reibel: People use it however they 

Pierson: I've looked and been un- 
able to find the information you just 
gave me, but perhaps I've not looked 
in the right places. 

Reibel: You can think of it in these 
terms. A tracheostomy is created when 
someone has a laryngectomy and has 
a 360 degree tracheal mucosa to skin 
margin. That is a true tracheostomy. 

Pierson: So you wouldn't regard 
what our people in the ICU do as tra- 

Reibel: 1 would not, until there is an 
epithelialized tract from the skin down 
to the tracheal margin. That's why 
there's a problem with loss of the can- 
nula for the first 2 weeks. That, I think, 
is one of the risks inherent in the way 
this thing has been sold to people. It's 
sold as convenient and less costly, and 

* David J Pierson MD, Division of Pulmonary 
Critical Care Medicine, Department of Medi- 
cine. University of Washington, Seattle, Wash- 


Respiratory Care • July 1999 Vol 44 No 7 


that's all true. But I think it's also 
potentially more risky. 

Thompson: Am I correct in under- 
standing that most of the patients I 
care for have a tracheotomy that be- 
comes a tracheostomy about a week 
or 2 later? 

Reibel: When there is a mature tract 
from the skin margin down to the tra- 
cheal opening the patient has a trache- 
ostomy. Most pediatric surgeons put a 
couple of retraction sutures in and tape 
them to the skin on either side and if you 
lose the airway, you pull them up and 
elevate the trachea and open the lumen. 

Heffner: I've tried to learn the 
proper use of these terms also. My 
review of the ear-nose-throat litera- 
ture, both textbooks and articles, sup- 
ports the position that the difference 
between tracheotomy and tracheos- 
tomy is the nature of the hole that you 
end up with. I'm a little bit at a dis- 
advantage because I don't speak 
Greek, but friends who do have told 
me that the root words have different 
meanings than what you described. 
■'Otomy" means to cut. "Ostomy" is 
the hole that is produced. So I think 
some confusion persists regarding use 
of these terms. 

Pierson: I think a lot of this is Greek. 
Although I'm usually prejudiced 
against jargon, I think I'm going to go 
home and refer to them both as a trach. 

Heffner: A review I read within the 
last year (but have been unable to lo- 
cate since) of the topic stated that only 
pedagogues worry about the differ- 
ence. Perhaps we should share these 

Branson: I want to make sure that 
everybody asks Dave if he could speak 
Greek, not Geek. 

Pierson: That goes in the Journal! 

Respiratory Care • July 1999 Vol 44 No 7 


Complications of Endotracheal Intubation and Tracheotomy 

John L Stauffer MD 


Selected Complications of Endotracheal Intubation 
Complications During the Intubation Procedure 
Complications While the Endotracheal Tube Is in Place 
Complications During and Immediately After Extubation 
Late Complications After Extubation 
Selected Complications of Tracheotomy 

Complications During the Tracheotomy Operation 
Complications While the Tracheostomy Tube Is in Place 
Complications During and Immediately After Decannulation 
Late Complications after Decannulation 
[Respir Care 1999;44(7):828-843] Key words: intubation, tracheotomy, tra- 
cheostomy, endotracheal tube, tracheostomy tube, artificial airway, adverse 
effects, larynx. 


Concern about complications stemming from the use of 
artificial airways has been evident since these devices were 
first introduced into clinical practice. When MacEwen suc- 
cessfully performed transoral endotracheal intubation in 
1878 for the relief of upper airway obstruction,' he rec- 
ognized the potential for complications of this procedure. 
His report of 4 cases includes description of adverse ef- 
fects associated with the use of endotracheal tubes (ETTs), 
including patient discomfort, cough, mucosal congestion, 
and glottic edema. MacEwen' s first patient actually expe- 
rienced no complications from the procedure: "After the 
operation was finished, . . . the tube was withdrawn, it 
having acted throughout without the slightest hitch."' When 
Jackson introduced the modern era of tracheotomy with 
his publication in 1909,^ he too was concerned about se- 
rious complications, reporting that 3 of his first 100 pa- 
tients died as a result of the tracheotomy operation itself. 

While some of the adverse events associated with en- 
dotracheal intubation and tracheotomy are inherent conse- 
quences of airway instrumentation, rather than true com- 
plications, most of the complications are avoidable, and a 
great deal of research has been published on the recogni- 
tion, management, and avoidance of these problems. The 
present discussion classifies the complications according 
to a conventional scheme, ^'t and addresses only the major 
complications of translaryngeal intubation and standard 
tracheotomy that are important in respiratory care and the 
practice of pulmonary and critical care medicine (Table 1). 
The emphasis is on prospective studies and recent publi- 
cations regarding adult patients suffering from critical ill- 
ness. The complications of percutaneous dilational trache- 
otomy, alternative airways, and special purpose ETTs are 
addressed elsewhere in these conference proceedings. 

I will use the common term endotracheal intubation to 
refer to translaryngeal (transoral or transnasal) intubation 
of the trachea with an ETT, and the term tracheotomy to 
refer to the surgical procedure of placing a tracheostomy 
tube (TT) into the trachea. 

John L Stauffer MD is affiliated with the Section of Pulmonary, Allergy, 
and Critical Care Medicine, Department of Medicine. The Milton S 
Hershey Medical Center, The Penn State Geisinger Health System, Her- 
shey. Pennsylvania. 

Correspondence: John L Stauffer MD, The Milton S Hershey Medical 
Center, MC H04I, The Penn State Geisinger Health System, PO Box 
850, Hershey PA 1703.1-0850. E-mail: 

Selected Complications of Endotracheal Intubation 

Several reviews of endotracheal intubation complica- 
tions have been published during the 1990s.'* ■* The 
present review addresses the selected complications 
listed in Table 2. 


Respiratory Care • July 1999 Vol 44 No 7 

Complications of Endotracheal Intubation and Tracheotomy 

Table 1 . Temporal Classification of Complications of Endotracheal 
Intubation and Tracheotomy 

Complications of endotracheal intubation 

• During the intubation procedure 

• While the endotracheal tube is in place 

• During and immediately after extubation 

• Late complications after extubation 

Complications of tracheotomy 

• During the tracheotomy operation 

• While the tracheostomy tube is in place 

• During and immediately after decannulation 

• Late complications after decannulation 

Table 2. Selected Complications of Endotracheal Intubation 

During the intubation procedure 

• Cardiac arrest 

• Nasal and oral trauma 

• Pharyngeal and hypopharyngeal trauma 

• Laryngeal and tracheal trauma 

• Main bronchus intubation 

• Pulmonary aspiration 

• Esophageal intubation 

While the endotracheal tube is in place 

• Nasal and oral ulceration; oral cellulitis 

• Sinus effusions and sinusitis 

• Otitis 

• Laryngeal injury 

• Tracheal injury 

• Pulmonary complications 

• Self-extubation 

• Mechanical problems with tube or cuff 

• Patient discomfort 

During and immediately after extubation 

• Sore throat 

• Stridor 

• Hoarseness 

• Odynophagia 

• True vocal cord immobility 

• Pulmonary aspiration 

• Cough 

Selected late complications after extubation 

• Laryngeal injury 

• Stenosis 

• Granuloma formation 

• Tracheal injury 

• Stenosis 

Complications During the Intubation Procedure 

The frequency of intubation complications depends pri- 
marily on the skill of the operator, the urgency of the 

procedure, and the patient's underlying medical condition. 
The rate of complications attributed solely to the intuba- 
tion procedure in critical care settings has not been well 
defined. Schwartz et al reported that all of 297 consecu- 
tive, supervised endotracheal intubations (92% oral, 8% 
nasal) in the intensive care unit (ICU) of a teaching hos- 
pital were successful, and 89% were successful on the first 
or second attempt.'" Eight percent of the intubations were 
described as "difficult." These investigators reported esoph- 
ageal intubation in 25 cases, main bronchus intubation in 
10 cases," pneumothorax in 2 cases, and suspected aspi- 
ration in 12 cases.'" For these immediate adverse events 
alone, the rate of complications was 16%. In an earlier 
prospective study, we recorded the same complications in 
42 (19%) of 226 intubations. '2 

In the emergency rooms of teaching hospitals, reported 
intubation complication rates range from 8%'-'' to 56%.'-* 
In a prospective study of prehospital emergency endotra- 
cheal intubation (96% oral) by staff physicians and nurse 
anesthetists of mobile ICUs in France, 689 (99.1%) of 691 
consecutive intubation attempts were successful, compared 
to success rates of 51-97.4% in other series that the au- 
thors reviewed. '5 Mechanical complications of intubation, 
such as esophageal intubation, main bronchus intubation, 
and dental trauma occurred in 15.9% of noncardiac arrest 
patients, and 8.1% of cardiac arrest patients. 

The latter data suggest that endotracheal intubation of 
critically ill adults by skilled personnel is nearly always 
successful. The overall complication rate of endotracheal 
intubation in critically ill adults is about 10-20%, and the 
rate may be lower in cardiac arrest patients than in others. 

Cardiac Arrest. Cardiac arrest from the endotracheal 
intubation procedure itself is, fortunately, rare. We ob- 
served one cardiac arrest in 226 intubations in ICUs.'- In 
the emergency room setting, 3 (0.5%) of 603 patients stud- 
ied in one series suffered cardiac arrest after intubation, 
and in only one instance was the intubation itself impli- 
cated.'^ Taryle et al prospectively observed no cardiac 
arrests in 43 patients intubated in the emergency room.''* 
In the anesthesia experience, Keenan and Boyan reported 
cardiac arrest in 1.7 cases and death in 0.9 cases per 10,000 
anesthesias.'* The rate of cardiac arrest directly attribut- 
able to endotracheal intubation in their study was not stated, 
but failure to ventilate the patient adequately accounted for 
nearly half of the cardiac arrests they observed. Mateer et 
al documented hypoxemia (defined as oxyhemoglobin sat- 
uration less than 90%) in 45 (21%) of 211 emergency 
endotracheal intubations.'^ 

Deaths attributed to endotracheal intubation itself are, 
apparently, rare. Adnet et al reported that no deaths oc- 
curred in a series of 358 patients intubated in the prehos- 
pital setting, although 4 cardiac arrests (1.1%) were attrib- 
uted to the intubation procedure.''' In their prospective 

Respiratory Care • July 1999 Vol 44 No 7 


Complications of Endotracheal Intubation and Tracheotomy 

study of 297 intubations in critically ill adults. Schwartz et 
al attributed no deaths to the intubation procedure itself.'" 
However, 7 (3%) of 270 patients died at the time of or 
within 30 minutes after endotracheal intubation, and sys- 
tolic hypotension was identified as a risk factor for death.'" 

Nasal and Oral Trauma. Minor nasal bleeding occurs 
in about half of nasal intubations in ICUs.'- Serious nasal 
hemorrhage and turbinate dislodgment are rare. Dental 
trauma during intubation has been reported in 0.9% of 
prehospital intubations,'-^ 0.1% of anesthesia intubations"* 
and in about 2% of critical care intubations. '^ Dental in- 
jury during intubation is a common source of malpractice 

Pharyngeal and Hypopharyngeal Trauma. Laceration 
of the walls of the pharynx and hypopharynx by intubation 
equipment is a serious but, fortunately, rare complication 
of intubation.-* Experience with these events is limited to 
case reports and small series. '''•2° Bleeding is the most 
common immediate finding. Barotrauma from positive 
pressure ventilation can result in subcutaneous emphy- 
sema, pneumomediastinum, pneumothorax, and cardiac ar- 
rest. 2' Later complications include the formation of hema- 
tomas and abscesses, which can grow large enough to 
obstruct the airway. 

Laryngeal and Tracheal Trauma. Laryngeal injury oc- 
curs in about 5-6% of anesthesia intubations. ^^ Lacera- 
tions of the mucosa of the larynx or trachea during intu- 
bation can result in immediate bleeding and hematoma 
formation. Vocal cord hematoma, which is usually left- 
sided, is the most common laryngeal injury of intubation. 
Arytenoid dislocation is less common.-'' Tracheal lacera- 
tion by the tip of the ETT, a very rare event, may present 
with findings of barotrauma.--* 

Main Bronchus Intubation. Right main bronchus intu- 
bation complicated about 9% of critical care intubations in 
separate prospective studies performed during the 
1970s. '2-5 In a study of emergency intubation of critically 
ill adults, in which anesthesia residents and attending phy- 
sicians were involved in many of the intubations, right 
main bronchus intubation occurred in 10 (3.7%) of 271 
intubations." In the prehospital setting, main bronchus 
intubation (unspecified) occurred in 17 (2.5%) of 691 in- 
tubations.''' Left main bronchus intubation is rare. 

Inadvertent right main bronchus intubation is, of course, 
avoidable. If it does occur, early detection by immediate 
examination of the post-intubation chest radiograph may 
prevent sequelae such as right-sided pneumothorax and 
atelectasis of the left lung. Note that the chest x-ray is 
superior to chest physical examination for detecting right 
main bronchus intubation."-'' 

Pulmonary Aspiration. The exact frequency of clini- 
cally significant pulmonary aspiration during intubation in 
nonanesthesia settings is not known. Rates of 8%'- in the 
ICU population and 3.5%-'' to 19%'^* in the emergency 
room population have been reported. 

Esophageal Intubation. Esophageal intubation is prob- 
ably the most serious complication of emergency intuba- 
tion, as it may result in irreversible brain injury from an- 
oxia-" and cardiorespiratory arrest. Inadvertent esophageal 
intubation occurred in 33 (5.5%) of 603 patients intubated 
in an emergency department,''' in 37 (5.4%) of 691 pa- 
tients in the prehospital setting in France,'-'' and in 25 (8%) 
of 297 intubation attempts in critically ill adults.'" Esoph- 
ageal intubation accounted for 4 (15%) of 27 cardiac ar- 
rests during intubation in a review of 163,240 anesthesias 
over a 15-year period."' Esophageal intubation is more 
likely to occur in the setting of cardiopulmonary resusci- 
tation than in more controlled settings. Early detection of 
esophageal intubation is possible with the use of colori- 
metric carbon dioxide detectors. 

Complications While the Endotracheal Tube 
Is in Place 

Complications occurring while the ETT is in place are, 
typically, insidious, and many of them do not become 
apparent until after extubation, but they are often avoid- 
able if care providers maintain a high level of suspicion 
and vigilance. 

Nasal and Oral Inflammation and Ulceration. In a 

prospective study of 379 ICU patients with nasal endotra- 
cheal intubation, Holdgaard et al found inflammation of 
the nostril or nasal septum in 76 patients (20.3%), nostril 
or septal ulceration in 1 10 patients (29%), nasal bleeding 
in 67 patients (18.8%), and damage to the conchae in 40 
patients (10.6%).-'^ 

Lip ulceration and cellulitis occasionally develop during 
prolonged tran.soral intubation. Lip edema, hemorrhage, 
and hemorrhagic crusts are commonly observed with 
prolonged intubation, but the pathogenesis of these le- 
sions, including the role of herpes virus infection, is not 
certain. We observed that 12 (15%) of 81 critically ill 
adults had ulcers or cellulitis of the lips by the time of 
extubation.'- Diligent respiratory care may prevent these 

Oral mucosal ulceration from oral ETTs is rare but some- 
times severe, particularly if an oropharyngeal airway is in 
place.'2 We found that ulceration of the palate had oc- 
curred in 6 (8%) of 81 patients by the time of extubation. '^ 

Sinus Effusions and Sinusitis. Sinus effusions occur in 
the majority of intubated patients, and computed tomog- 


Respiratory Care • July 1999 Vol 44 No 7 

Complications of Endotracheal Intubation and Tracheotomy 

raphy (CT) scan evidence of sinusitis is found early in the 
course of endotracheal intubation.'^ Radiographic evidence 
of maxillary sinus intlammation on CT scans was found in 
45 (30%) of 149 patients with nasal intubation and 33 
(22%) of 15 1 patients with oral intubation in 1 prospective 

Frank maxillary sinus infection (nosocomial sinusitis) 
complicates both nasal and oral endotracheal intubation 
(and the use of nasogastric tubes) and is a risk factor for 
ventilator-associated pneumonia (VAP).'' Clinical experi- 
ence in the 1980s suggested that up to one half of pro- 
longed nasal intubations are complicated by sinus infec- 
tions.''' " In more recent, carefully conducted studies, from 
38%" to 69%''* of intubated patients with radiographic 
maxillary sinusitis had frank maxillary sinus infection. 
Rouby et al reported VAP in 67% of patients with infec- 
tious maxillary sinusitis, and in 38% of these patients the 
organisms isolated from sinus aspirates were identical to 
those isolated from the lung by bronchoalveolar lavage." 
Holzapfel et al observed that nosocomial maxillary sinus- 
itis increased the risk of VAP by a factor of 3.8, and that 
there were no significant differences between the nasal 
and the oral routes of intubation in the occurrence rate 
of nosocomial sinusitis or VAP.'** The risk of infectious 
sinusitis appears to increase with the duration of 

True sinusitis, as opposed to simple sinus effusion, is 
difficult to diagnose in intubated patients. Recent studies 
have emphasized the use of CT scanning followed by sur- 
gical aspiration and culture of secretions to establish the 
diagnosis. Clinical findings such as purulent nasal secre- 
tions alone are not reliable in the diagnosis. Gram-negative 
bacteria are the most common pathogens isolated in intu- 
bation-associated sinusitis, but Gram-positive bacteria, an- 
aerobic organisms, and fungi are isolated often enough to 
make broad spectrum anti-microbial therapy necessary in 
most cases. Practice guidelines have not been developed 
for the diagnosis and treatment of sinus effusions and si- 
nus infection in the setting of prolonged endotracheal in- 
tubation."^ For an established diagnosis of nosocomial si- 
nusitis, antibiotic therapy is advised. Conversion from the 
nasal to the oral route of intubation has also been recom- 
mended." One report suggests that surgical drainage is 
infrequently necessary in managing nosocomial sinusitis.-"' 

Otitis. Endotracheal intubation can interfere with nor- 
mal eustachian tube function.-*' We noted that 1 1 (8.7%) of 
126 adult ICU patients developed evidence of otitis media 
or otitis externa while intubated.'- Co-existing prolonged 
nasogastric intubation was identified as a risk factor. Mid- 
dle ear effusions have been reported in 87% of pediatric 
ICU patients with nasotracheal intubation.-*- and in 29% of 
adults intubated for longer than 48 hours.-*' In tympano- 
centesis results, Gram-negative organisms predominate.'*' 

Orotracheal intubation is more of a risk factor for middle 
ear effusions than nasotracheal intubation. 

Laryngeal Injury. Numerous investigators have ob- 
served that nearly all patients who survive prolonged en- 
dotracheal intubation for critical illness display some fea- 
tures of laryngeal injury by the time of extubation, which 
indicates that laryngeal injury occurs while the ETT is in 
place. Thomas et al found some evidence of laryngeal 
pathology at extubation in 88% of adult and pediatric pa- 
tients.-*'* Colice et al prospectively observed some degree 
of laryngeal injury immediately after prolonged endotra- 
cheal intubation in 77 (94%) of 82 patients, and severe 
injury in 19 patients (23%).-*^ In an excellent prospective 
study, Santos et al reported laryngeal injury ranging from 
erythema (90-95%) to ulceration (65-79%) and granu- 
loma formation (35-45%) in 62 men surviving after oral 
endotracheal intubation (mean 5-6 days)."** Few studies 
have attempted to examine the larynx with fiberoptic en- 
doscopy during the period of intubation, because of the 
difficulty of visualizing the endolarynx while an ETT is in 

A wide range of supraglottic, glottic, and subglottic com- 
plications have been observed, including simple edema, 
inflammation, and minor submucosal hemorrhage, vocal 
cord paralysis and paresis, vocal cord hematomas, granu- 
loma formation, and severe mucosal ulceration. Santos et 
al reported laryngeal erythema in 90-95% of survivors 
after 5-6 days of oral endotracheal intubation, resolution 
of which required as long as 9 weeks.-*^ In their analysis, 
the use of a larger (size 8.0) ETT and nasogastric intuba- 
tion were significant risk factors for laryngeal erythema.-*^ 

The most common and most worrisome laryngeal com- 
plication while an ETT is in place is injury to the glottis. 
Concern about silent laryngeal damage from the ETTs 
pressure against the posterior laryngeal wall is the primary 
justification for performing tracheotomy for long-term air- 
way maintenance. Posterior vocal cord and arytenoid ul- 
ceration is the most common serious complication of en- 
dotracheal intubation, occurring in 37%,-*^ 51%,'- 76%,'*^ 
and 79%-"* of patients in several prospective studies. Pres- 
sure exerted by the shaft of the ETT on the posterior rim 
of the glottis, which serves as a fulcrum for the leveraging 
action of the ETT, ulcerates the mucosal surfaces of the 
arytenoids, the interarytenoid space, the cricoarytenoid 
joints, and the posterolateral aspects of the cricoid carti- 
lage. (Fig. i)s. 12.23.48-50 jfi severe cases ulceration is deep 
enough to destroy laryngeal cartilage, inviting local infec- 
tion*"' and further intense inflammation. Cricoid cartilage 
abscess can eventually develop at the site of posterior 
glottic ulceration.'''^ In survivors, healing of these ulcers 
is remarkably efficient, as severe granuloma formation 
or laryngeal stenosis''- is unusual (see further discussion 

Respiratory Care • July 1999 Vol 44 No 7 


Complications of Endotracheal Intubation and Tracheotomy 

Fig. 1. The pathogenesis of laryngeal injury from endotracheal 
intubation. Because the endotracheal tube is round and the glottis 
is pentagonal, the ETT applies pressure on the posterior glottis. 
The arrows indicate the points of highest pressure. (From Refer- 
ence 50, with permission.) 

Tracheal Injury. Tracheal injury that occurs while the 
ETT is in place, like laryngeal injury, ranges in severity 
from mild to severe. Ciliostasis, superficial mucosal in- 
flammation, hyperemia, and mild edema at the cuff site are 
inevitable consequences of tracheal intubation."* 

Cinematographic techniques and scanning and transmis- 
sion electron microscopy have detected impairment of mu- 
cociliary clearance and damage to the ciliated tracheal 
epithelium, with actual loss of cilia as a result of tracheal 
intubation. ^''•^'* Airway colonization by bacteria, and squa- 
mous metaplasia of the tracheal epithelium''^ '''' also are 
common and unavoidable effects of an ETT, which rep- 
resents a foreign body in the trachea." Epithelial trauma 
from suctioning the trachea is unavoidable, but can be 
minimized with proper suctioning technique. 

Most of the interest in tracheal injury from endotracheal 
intubation has focused on cuff site ulceration from the 
lateral tracheal wall pressures exerted by the inflated cuff. 
A great deal has been learned about this problem over the 
last 30 years. New understandings of the pathogenesis of 
cuff site injury have led to the universal use in ICUs of 
high-volume, low-pressure cuffs on modern ETTs and TTs, 
which has substantially reduced the frequency of severe 
cuff site ulceration."* We found tracheal mucosal ulceration 
at autopsy in only 15% of patients after prolonged endo- 
tracheal intubation with soft-cuff ETTs.'^ 

The pathogenesis of tracheal cuff site ulceration has 
been studied more thoroughly than that of any other com- 
plication of artificial airways. Figure 2 illustrates the piv- 
otal role of capillary perfusion pressure and lateral tracheal 
wall pressure from the inflated cuff. The normal capillary 
perfusion pressure in the tracheal mucosa has been esti- 
mated in animal models to be about 22 mm Hg.''' "■* Main- 
tenance of cuff inflation pressures below 20-22 mm Hg 
greatly reduces the risk of cuff site ischemia and eventual 
ulceration, compared to the higher pressures exerted by 
low-volume, high-pressure cuffs or overinflated soft 
cuffs.'''*-*' However, maintaining cuff pressures slightly 
lower than this (20 cm HiO or 15 mm Hg) is associated 
with an increased risk of pneumonia.*'- The dilemma of 
maintaining intracuff pressures high enough to seal the 
airway and prevent aspiration yet low enough to avoid 
mucosal ischemia has been recognized for many years.''' 
Based on studies of blue dye aspiration in patients under 
general anesthesia, Bemhard et al advised maintaining in- 
tracuff pressures of 25-34 cm HjO (18-25 mm Hg) in 
soft-cuff ETTs to avoid aspiration." The available data 
suggest that an intracuff pressure in the narrow window of 
25-30 cm HjO (18-22 mm Hg) is the best compromise 
between the risk of aspiration and the risk of ischemia. 

Other tracheal complications while the ETT is in place 
include granuloma formation and submucosal hemorrhage. 
Tracheal cartilage necrosis from infection and cuff site 
ulceration, tracheoarterial fistula, and tracheoesophageal 
fistula are rare complications during endotracheal intuba- 
tion with soft-cuff ETT. Tracheal dilation during the pe- 
riod of intubation has been observed in 13.5% of patients, 
and this finding usually portends a poor outcome.''" 

Pulmonary Complications. Aspiration and pneumonia 
are the main pulmonary complications of endotracheal in- 
tubation. Retention of lower airway secretions, leading to 
atelectasis and poor gas exchange, is another common 
problem. Bronchoconstriction also occurs and can be a 
difficult management challenge in patients with underly- 
ing chronic obstructive pulmonary disease or asthma. 

Gross aspiration of large volumes of gastric contents or 
upper airway secretions is uncommon during endotracheal 
intubation, because the cuffed tube protects the lower air- 
way. Aspiration is more common in patients with TT than 
those with ETT,'''' but any type of cuffed intratracheal tube 
can impair swallowing and increase the risk of aspira- 
tion.'''' Leakage of fluid along the folds of the ETT cuff 
fabric and into the trachea has been observed in trachea 
models and excised human tracheas.''^ Some authorities 
advise maintaining a minimum intracuff pressure of 20-25 
cm HiO to reduce the occurrence of this micro-aspiration 
phenomenon.'''' This recommendation is supported by the 
results of Rello et al, who found that the risk of VAP is 


Respiratory Care • July 1999 Vol 44 No 7 

Complications of Endotracheal Intubation and Tracheotomy 

Pathogenesis of Tracheal Cuff Site Injury 

High cufT pressure 


High lateral tracheal wall pressure, 

exceeding capillary perfusion pressure 

Mucosal ischemia and inflammation 

Mucosal necrosis 


Mucosal ulceration 

Extubation 1^ 

^ Continued intubation 

Healing process 

Destruction of tracheal cartilage 

k: si/ ^ 


Restoration Granuloma Tracheal 

Loss of structural integrity of 

of normal formation stenosis 

tracheal wall 


1^ s|/ iJ 

Erosion into Tracheal Tracheomalacia 

adjacent dilatation 


1^ iJ 

Tracheovascular fistula Tracheoesophageal fistula 

Fig. 2. The pathogenesis of tracheal injury at the cuff site. (Modified from Reference 4, with permission.) 

reduced by maintaining cuff pressure above 20 mm Hg 
(about 26 cm W.O).^^- 

Occult aspiration of material from the hypopharynx does 
occur, as determined by staining of tracheal secretions 
after blue dye is placed on the tongue. In one study it was 
observed in 20% of patients with soft-cuff ETTs,''** and 
another study observed a frequency of 17-25%.''-'' The 
clinical importance of these findings is not entirely clear. 
Nevertheless, aspiration of hypopharyngeal secretions 
contaminated with Gram-negative bacilli and other micro- 
organisms colonizing the upper airway and the stomach 
sets the stage for VAP. The frequency of VAP during 
endotracheal intubation ranges from 9% to 22%, and the 
mortality may be as high as 71%.'''*™ More than one re- 
intubation during a period of mechanical ventilation has 
been found to be an independent risk factor for the devel- 
opment of VAP.™ 

The pathogenesis of VAP has been studied extensively 
in the last decade. The roles of contaminated gastric se- 
cretions, sinusitis, the leakage of contaminated subglottic 
secretions into the trachea, and other risk factors have 
received special attention.^' Rello et al reported that leak- 
age of colonized subglottic secretions past the ETT cuff is 

the most important risk factor for VAP in the first 8 days 
after intubation.*^ Preliminary tests of an ETT designed 
with a channel that allows continuous aspiration of secre- 
tions above the cuff suggest that this device does decrease 
the risk of VAP.«-72 

Unplanned Extubation. Unplanned extubation, whether 
intentional or inadvertent, often results in serious cardiac 
or respiratory complications. ^''■^■^ Self-extubation occurs in 
about 10-20% of intubated patients in ICUs,"* and is a 
quality-of-care issue. The rate of self-extubation may be 
reduced by staff vigilance and appropriate practice guide- 
lines.^'-''^ About two thirds of self-extubations are delib- 
erate acts by the patient.'''' ''*' Approximately half of self- 
extubating patients require reintubation.--'''''^-''' 

A recent large prospective, multicenter study in France 
recorded unplanned extubations in 46 (10.8%) of 426 me- 
chanically ventilated patients.**" Agitation was observed at 
the time of the unplanned extubation in 61% of the pa- 
tients. Multivariate analysis revealed 4 factors that predis- 
pose to unplanned extubation: (1) chronic respiratory fail- 
ure, (2) ETT fixation with thin adhesive tape, (3) oral route 
of intubation, and (4) lack of intravenous sedation. A re- 

Respiratory Care • July 1999 Vol 44 No 7 

Complications of Endotracheal Intubation and Tracheotomy 

cent prospective case-control study confirmed that oral 
intubation and inadequate sedation are key risi^ factors for 
unplanned extubation.*' Another recent investigation em- 
phasized the importance of agitation and a hospital-ac- 
quired adverse event as significant independent risk fac- 
tors for self-extubation.**2 Close monitoring of agitated 
patients during intubation is a fundamental component of 
guidelines aimed at reducing the frequency of unplanned 

Mechanical Problems with the ETT and Cuff: Mal- 
position. Mechanical problems with ETT position and 
performance are observed in about 6% of endotracheal 
intubations in critically ill adults.'- The most common of 
these problems are upward or downward migration of the 
ETT, partial or complete ETT occlusion, disconnections 
from the ventilator, and faulty cuff inflation. Misplace- 
ment of the ETT during the period of intubation was ob- 
served in 22 (7.9%) of 278 critically ill adults in the ret- 
rospective arm of a recent study by Kollef et al, and in 5 
cases, the consequences of tube misplacement were seri- 
ous.**-^ After instituting a quality improvement program, 
the authors observed 113 (46%) ETT misplacements in 
246 prospectively studied patients, and no serious conse- 
quences developed.**^ 

Inability to seal the airway with ETT cuff inflation is a 
vexing problem in 1 1%**'* to 25%*'' of endotracheal intu- 
bations. When an ETT is removed because of an alleged 
"massive air leak," a defect in the ETT cuff is found in 
only in a minority of cases, and tube malposition is im- 
plicated as the most likely cause of the apparent leak.**'' 

Patient Discomfort. The pain and suffering experienced 
by patients during endotracheal intubation has, unfortu- 
nately, received little attention. A telephone survey of pa- 
tients who survived endotracheal intubation for critical 
illness revealed a high level of distress related to inability 
to communicate, anxiety, pain, distress in clearing airway 
secretions, panic reactions, discomfort during tracheal suc- 
tioning and extubation, and other unpleasant experienc- 
es.*'' More clinical investigation is needed to understand 
the distress of intubated patients and to develop more ef- 
fective intervention. 

Complications During and Immediately 
After Extubation 

Serious complications at the time of extubation in the 
critical care setting are, fortunately, unusual. In the anes- 
thesia experience, complications of tracheal extubation are 
also very uncommon. Adverse events in anesthesia prac- 
tice (reviewed elsewhere)*** include difficulty in tube re- 
moval, airway trauma, tracheomalacia, laryngospasm, la- 
ryngeal edema, airway obstruction, vocal cord paralysis. 

laryngeal incompetence, and exaggerated heart rate and 
blood pressure responses. Asai et al prospectively recorded 
symptoms and complications in 195 (19.4%) of 1,005 pa- 
tients after extubation following general anesthesia.**** The 
most frequent problems observed immediately after extu- 
bation were coughing (6.6%), desaturation (arterial satu- 
ration oxygen < 90%) (2.4%), breath-holding (2.0%), air- 
way obstruction (1.9%), and laryngospasm (1.7%).**' 

Sore Throat. We found that 29 (42%) of 69 patients 
complained of sore throat after prolonged intubation. '^ This 
contrasts with a 14-15% reported incidence of sore throat 
following tracheal intubation for general anesthesia.'"' "^ 

Stridor. Mild to moderate degrees of stridor occur in up 
to 5% of extubations in critical care settings, ^'^ while se- 
vere stridor occurs in less than 1% of cases.'^ Stridor is 
usually a result of glottic or subglottic edema, not frank 
laryngospasm."- Although laryngeal edema is observed in 
about half of patients at or immediately after extubation,"^ 
it is rarely severe enough to cause stridor. Airway obstruc- 
tion by secretions, blood, or foreign material can also cause 
postextubation stridor. Arytenoid dislocation and vocal cord 
paresis or paralysis are infrequently responsible for post- 
extubation stridor.'* Only 1% of patients experiencing post- 
extubation stridor require re-intubation.'^.'^'* 

Topical epinephrine and parenteral corticosteroids are 
commonly prescribed for management of postextubation 
stridor, but available data have not shown these treatments 
to be effective in adults.''^ One recent study of small chil- 
dren suggests that pretreatment with dexamethasone does 
reduce the frequency of postextubation stridor and other 
signs of airway obstruction.**-^ 

Hoarseness. The frequency of hoarseness following ex- 
tubation in prospective studies of critically ill adult pa- 
tients ranges from 56%'''' to 71%,'- being more common 
with oral intubation and with larger tubes. In a large study 
of nasotracheal intubation, Holdgaard et al reported hoarse- 
ness in 40.7% of patients. 2** Santos et al reported that in 62 
men surviving after 5-6 days of oral endotracheal intuba- 
tion, 56% of those intubated with size 7.5 ETT and 69% of 
those with size 8.0 ETT suffered hoarseness. 2^* In most 
cases, complete aphonia was observed initially. 

Failure of postextubation hoarseness to resolve within 2 
weeks suggests the presence of serious complications such 
as vocal cord paralysis or paresis, cricoarytenoid joint dys- 
function, laryngeal granuloma,*** or other problems. Pro- 
spective observations of the resolution of laryngeal injury 
after extubation support the use of endoscopic evaluation 
if hoarseness persists beyond 4-8 weeks."*'**'' 

Cough. We found that 26% of ICU patients had a new 
cough following prolonged endotracheal intubation. '^ 


Respiratory Care • July 1 999 Vol 44 No 7 

Complications of Endotracheal Intubation and Tracheotomy 

Odynophagia. Severely painful swallowing and painful 
phonation immediately after extubation are very rare. When 
these symptoms occur, diagnoses to consider include pos- 
terior glottic infection or ulceration, or abscess formation 
on the cricoid cartilage.'' 

True Vocal Cord Immobility. Santos et al observed 
true vocal cord immobility in 12 (19%) of 62 patients who 
survived after a mean of 5-6 days of endotracheal intu- 
bation.'**' The vocal cord immobility was unilateral in all 
but one case and was significantly related to the duration 
of intubation. In half of the cases, true vocal cord immo- 
bility was delayed, appearing 1-10 weeks after extubation. 
Resolution required as long as 10 weeks.-"' Bilateral vocal 
cord paralysis after endotracheal intubation is a severe but 
very rare complication.'^** 

Pulmonary Aspiration. Santos et al found clinical ev- 
idence of aspiration in 55-64% of men after extubation 
following 5-6 days of oral intubation.'"' Laryngeal incom- 
petence following extubation can permit aspiration into 
the trachea. A sensory deficit that compromises protective 
hypopharyngeal and laryngeal reflexes has been impli- 
cated in this phenomenon.'*'' In postoperative patients, la- 
ryngeal incompetence can persist for 4 hours after extu- 

Numerous defects in deglutition are common after oro- 
tracheal intubation, with or without subsequent tracheoto- 
my."* A prospective endoscopic study of orally intubated 
trauma patients revealed that 9 (45%) of 20 aspirated blue 
dye within 24 hours of extubation, and in 4 (44%) of the 
9 cases aspiration was silent.'"' None of the patients who 
aspirated blue dye developed pulmonary complications. 
Burgess et al found that even alert postoperative cardiac 
surgery patients may aspirate contrast dyes immediately 
after extubation (33%) and up to 4 hours later (20%), 
possibly as a result of an inability of the larynx to sense 
foreign material.'''' In the ICU population, this "sensory 
denervation" was found by Colice and co-workers in 13 
(24%) of 54 men following extubation.-''' Aspiration of 
pharyngeal material may occur even when the gag reflex is 
intact.' 00 

Late Complications After Extubation 

Most of the late complications after extubation repre- 
sent abnormal healing of ETT-induced laryngeal and tra- 
cheal injury. Airway stenosis typically appears weeks to 
months after extubation. Laryngeal granulomas typically 
form while the ETT is in place and are commonly seen by 
the time of extubation, but granulomas can also develop in 
the healing process late after extubation. 

Table 3. Prospective Studies of Laryngeal and Tracheal Stenosis 







Andrews et al'^' 



Dane et al'-'* 



Stauffer et al'^ 






Kastanos et al'*' 






Colice et al*' 



Santos et al*" 



van Heurn et alt'*' 






*Glottic/subgloltic stenosis from endotracheal inluliation. 

tTracheal stenosis from tracheotomy. Data are included if the airway diameter was reduced 

s 25''f or the patient had symptoms of tracheal stenosis. 

^Percutaneous dilational tracheotomy. 

(Modified from Reference 39.) 

Laryngeal Injury. In one carefully designed prospec- 
tive study, serial endoscopy of 54 survivors was performed 
after extubation to study the healing of laryngeal injury 
from endotracheal intubation.'*^''^ In 42 (78%) healing by 
reepithelialization was complete within 8 weeks.'''' Hoarse- 
ness disappeared as laryngeal injury resolved over time, 
and complete laryngeal healing was evident within 8-12 
weeks. The healing of laryngeal injury after extubation has 
been observed over 3-5 months by other investigators. '"^ 
Complaints of dyspnea, hoarseness, or stridor in the 
year following prolonged endotracheal intubation should 
alert the clinician to the possibility of laryngeal stenosis. In 
one report, 3 (10%) of 30 survivors of acute respiratory 
distress syndrome (ARDS) presented with symptoms of 
laryngeal stenosis 4-12 months after hospital discharge. '"^ 

Laryngeal Stenosis. Laryngeal stenosis is the most feared 
late complication of endotracheal intubation. However, it 
is important to emphasize that this is an uncommon com- 
plication of endotracheal intubation for critical illness in 
adults. Prospective studies of laryngeal stenosis from en- 
dotracheal intubation report frequencies ranging from 
0%46.97 (Q 6% 52 jhg mean rate of laryngeal stenosis com- 
plicating endotracheal intubation in 10 prospective studies 
over the last 30 years is 2.9%, a rate which compares 
favorably to the 13.2% rate of tracheal stenosis of 25% or 
greater in survivors following tracheotomy (Table 3). How- 
ever, it must be recognized that laryngeal stenosis is al- 
ways symptomatic and difficult to manage, especially if 
the posterior commissure is stenotic.^ Tracheal stenosis 
below the cricoid ring, on the other hand, is not always 
symptomatic, even when it exceeds 25%, and is more 
easily managed surgically than laryngeal stenosis. Dilation 

Respiratory Care • July 1999 Vol 44 No 7 


Complications of Endotracheal Intubation and Tracheotomy 

procedures, stent placement, and laser therapy are the main 
treatment options.'' 

Laryngeal Granuloma. Laryngeal granulomas are small 
tufts of granulation tissue that can form at the site of 
laryngeal mucosal injury from intubation. They typically 
grow at the margins of laryngeal ulcers, are usually bilat- 
eral, and involve the true vocal cords."** As complications 
of endotracheal intubation, they are more common than 
tracheal granulomas. Laryngeal granulomas complicating 
endotracheal intubation occur in 7%*^ to 27%'*'' of criti- 
cally ill adults after extubation. They have not been ob- 
served in children''^ and are very rare from anesthesia 
intubation. '""' They usually resolve spontaneously and are 
rarely large enough to compromise the airway or to require 
surgical excision. 

The time course of development of laryngeal granulo- 
mas is of interest. We reported that only one (2%) of 41 
patients dying while intubated and examined at autopsy 
had a true vocal cord granuloma. '^ Two prospective stud- 
ies using laryngoscopy to evaluate the larynx after extu- 
bation both reported the frequency of true vocal cord gran- 
ulomas to be 42% after intubation for 1 day"*^ to 3 days."** 
Santos et al reported that 57% of the laryngeal granulomas 
in their series of 97 patients developed an average of 4 
weeks after extubation."** Serial laryngoscopy indicates that 
most of these lesions resolve with time.'**'*'' These findings 
suggest that laryngeal granulomas develop at various times 
in the healing phase of true vocal cord ulceration, with 
eventual resolution in most cases. 

Tracheal Injury. Tracheal stenosis is the most impor- 
tant late complication of endotracheal intubation involving 
the trachea. Tracheal dilation, tracheomalacia, and tracheal 
granuloma formation are very rare complications of endo- 
tracheal intubation in the modem era of soft-cuff ETTs."* 

Tracheal Stenosis. Since the advent of the soft-cuff ETT, 
significant tracheal stenosis following endotracheal intu- 
bation is very unusual. '"^"^ We detected asymptomatic 
mild (s 25% narrowing) tracheal stenosis in 3 (1 1%) of 
27 patients studied with tracheal tomography after extu- 
bation. '^ Kastanos et al detected cuff-site tracheal stenosis 
(25- 30% narrowing) in 2 (11%) of 19 patients studied 
after intubation periods of 9 and 14 days."^ Santos et al 
reported no evidence of "laryngotracheal" stenosis in 62 
adults surviving prolonged endotracheal intubation."** 

Little is known about the natural course of tracheal ste- 
nosis that complicates endotracheal intubation. In our pro- 
spective series, one patient with mild tracheal stenosis 
after endotracheal intubation showed resolution on subse- 
quent tracheal tomograms, whereas tracheal stenosis after 
tracheotomy persisted in 3 patients. '^ 

It is important for clinicians to maintain a high index of 
suspicion in order to make the correct diagnosis of tracheal 
stenosis. Symptomatic tracheal stenosis following endo- 
tracheal intubation (or tracheotomy) typically presents from 
several weeks to 12 months following extubation or de- 
cannulation with labored breathing, difficulty clearing se- 
cretions, cough, dyspnea, hoarseness, stridor, or combina- 
tions of these symptoms, ■o''- 'o* Inspiratory stridor reportedly 
occurs only when the tracheal lumen is reduced to 3-4 
mm diameter or less.'"* Unfortunately, the symptoms of 
advanced tracheal stenosis are often misattributed to chronic 
obstructive pulmonary disease, asthma, other underlying 
respiratory diseases, or even hysteria. Appropriate imag- 
ing studies (CT or magnetic resonance imaging) of the 
larynx and trachea and/or fiberoptic bronchoscopy are re- 
quired to confirm the diagnosis of tracheal stenosis. The 
physical examination and pulmonary function tests (flow- 
volume loop) may suggest the diagnosis of severe airway 
stenosis, but they are neither sensitive nor specific enough 
to establish the diagnosis with certainty.' 2- '"^ 

Selected Complications of Tracheotomy 

The complications of cricothyroidotomy and minitra- 
cheotomy are not addressed in this review, and those of 
percutaneous dilational tracheotomy are addressed only 
briefly herein. Complications of standard tracheotomy have 
been reviewed elsewhere.^'"''-"''' '" Selected complica- 
tions of tracheotomy are listed in Table 4. 

The overall mortality rate of tracheotomy in the 1950s 
and 1960s was 0-5.3%. "^."^ Death rates of 2.8%"* and 
3.4%"^ were reported in large personal series of trache- 
otomies. In a more recent prospective series of 124 adult 
tracheotomies, Goldstein et al reported no deaths. "^ 

Stemmer et al reviewed 403 deaths in tracheotomized 
patients."* The operation itself accounted for 36 (8.9%) of 
the deaths, and hemorrhage was the most common fatal 
complication. In a literature review of 1,928 tracheotomies 
in 1 972, in which the overall mortality rate of tracheotomy 
was 1 .6%, the most common fatal complications (in de- 
creasing order) were tracheotomy hemorrhage, displace- 
ment of the TT, infection, and tube obstruction."^ 

Several prospective investigations have compared the 
airway management complication rates of patients receiv- 
ing early tracheotomy versus late tracheotomy. '"2- "'*"'^ In 
a study of 74 trauma patients, Dunham and LaMonica 
found no significant differences in rates of major compli- 
cations, laryngotracheal pathology, or pulmonary infection 
between patients who had tracheotomy at 3-4 days and 
those who had tracheotomy at 14 days after endotracheal 
intubation."** Another study of 106 trauma patients re- 
vealed that tracheotomy in the first week of mechanical 
ventilation significantly reduced duration of mechanical 
ventilation and length of stay in the ICU and the hospital 


Respiratory Care • July 1999 Vol 44 No 7 

Complications of Endotracheal Intubation and Tracheotomy 

Table 4. Selected Complications of Tracheotomy 

During the tracheotomy operation 

• Cardiac arrest 

• Paratracheal tube placement 

• Hemorrhage 

• Recurrent laryngeal nerve injury 

• Pneumothorax, pneumomediastinum, and subcutaneous emphysema 

While the tracheostomy tube (TT) is in place 

• Stomal infection 

• Hemorrhage 

• Tracheal injury 

• Tracheomalacia 

• Granuloma 

• Tracheoesophageal fistula 

• Tracheovascular fistula 

• Incidental dislodgement and decannulation 

• Pulmonary complications 

• Mechanical problems with TT or cuff 

During and immediately after decannulation 

• Difficult removal of TT due to tight stoma 

Late complications after decannulation 

• Poor wound healing 

• Scar and keloid 

• Persistent open fistula 

• Tracheal injury 

• Stenosis 

• Dilatation 

when compared to tracheotomy after 8-21 days of me- 
chanical ventilation."'' However, a recent multicenter, ran- 
domized, prospective study failed to demonstrate that ear- 
lier tracheotomy reduced the frequency of airway 
complications, ICU length of stay, nosocomial pneumonia, 
or death in head trauma, nonhead trauma, or critically ill 
nontrauma adults. '"^ The authors observed more vocal cord 
ulceration and subglottic inflammation in the patients who 
underwent tracheotomy later (ie, had prolonged endotra- 
cheal intubation). None of these randomized prospective 
studies have reported statistically significant reduction in 
laryngeal or tracheal injury by performing tracheotomy 
early in the course of prolonged airway maintenance. 

and airway suctioning have also been implicated as causes 
of sudden death during or immediately after tracheoto- 
n^y 109.1 16 Bradycardia from tracheal manipulation is also a 
concern. '09.120 

Paratracheal Tube Placement. "False passage" or mal- 
position of the TT at the time of tracheotomy occurs when 
the tip of the TT is inadvertently directed into the para- 
tracheal tissues, usually the pretracheal space. Inability to 
ventilate and oxygenate the patient is the usual presenting 
sign of this disaster. '^o 

Hemorrhage. Because published reports do not clearly 
distinguish intraoperative from postoperative bleeding, this 
complication is discussed below. 

Recurrent Laryngeal Nerve Injury. Inadvertent tran- 
section of one or both recurrent laryngeal nerves from 
tracheotomy incisions that are too wide or deep can cause 
vocal paralysis that is not evident until after decannula- 
tion. '^° Laryngoscopy while the TT is in place may also 
identify this problem.'"'' The exact frequency of this com- 
plication is unknown, but it appears to be a very rare event. 

Pneumothorax, Pneumomediastinum, and Subcutane- 
ous Emphysema. Pneumothorax complicates as many 
as 4-5% of tracheotomies.""'"-^"'* In a personal series of 
389 tracheotomies performed during the 1950s. McClel- 
land found that 16 patients (4.1%) developed "surgical 
emphysema" and/or pneumothorax."^ Stock et al observed 
that 2 (2.5%) of 81 neurosurgical patients requiring elec- 
tive tracheotomy had supraclavicular subcutaneous em- 
physema following the operation.'-' This complication is 
much more common in children than in adults'"'' and is 
reported to be the most common fatal complication of 
tracheotomy in children. '^2 False passage of the tracheal 
tube into the paratracheal space, injury to the apical pleu- 
rae, spontaneous rupture of lung blebs, and dissection of 
air into the mediastinum through the stoma during forceful 
inspiratory efforts have been implicated as the causes of 
this complication. "^'2' 

Complications While the Tracheostomy Tube 
Is in Place 

Complications During the Tracheotomy Operation 

Cardiac Arrest. Cardiac arrest during tracheotomy is 
very rare. In our series, one patient with erroneous surgical 
placement of the tracheostomy tube into the pretracheal 
space suffered a cardiac arrest on the operating table. '- 
The patient was subsequently resuscitated. Malposition of 
the TT, apnea, and hypotension during emergency trache- 
otomy for acute respiratory failure, traction on the trachea. 

Stomal Infection. We prospectively observed mild peris- 
tomal cellulitis or excessive purulent exudate at the stoma 
in 19 (36%) of 51 patients after elective tracheotomy.'- In 
contrast, a retrospective study reported stomal infection in 
only 4% of 84 neurosurgical patients after tracheotomy.'" 
Severe cellulitis and mediastinal abscess formation are very 
unusual complications of standard tracheotomy.'"'' Stomal 
infection is reportedly less common with percutaneous di- 
lationai tracheotomy than with standard tracheotomy. None 

Respiratory Care • July 1999 Vol 44 No 7 

Complications of Endotracheal Intubation and Tracheotomy 

of 124 consecutive adult patients who underwent bedside 
tracheotomy developed stomal cellulitis.'" 

Hemorrhage. The reported frequency of hemorrhage 
from tracheotomy ranges from 0% to 37%.'" We recorded 
stoma site blood oozing of more than mild degree in 19 
(36%) of 51 ICU patients following tracheotomy.'- Major 
hemorrhage was observed in only one of the 5 1 patients as 
a result of tracheal erosion at the level of the TT cuff into 
the inferior thyroid artery. In a recent retrospective study 
of 470 consecutive tracheotomy operations, Upadhyay et 
al found that bleeding was the most common complication 
of the procedure, occurring in 20 (4.3%) cases. '-'' In a 
prospective study of bedside tracheotomy in 124 ICU pa- 
tients, only 2 (1.6%) experienced minor hemorrhage, and 
none had major hemorrhage from the procedure."'' Four 
(10%) of 40 tracheotomy patients in another prospective 
series experienced hemorrhage, which was major in 2 cas- 
es.'-'' In an older series of 389 tracheotomies, McClelland 
reported 4 deaths from major hemorrhage."'' Aspiration of 
blood from venous hemorrhage accounted for 7 deaths in 
a series of 36 tracheotomy-related deaths.'"' 

Tracheal Injury. Tracheal mucosa and tracheal wall 
injuries follow the same pattern as those created by ETT 
cuffs and suction catheters. We observed tracheal cuff site 
submucosal hemorrhage at autopsy in 3 (14%) of 22 pa- 
tients who died following prolonged endotracheal intuba- 
tion followed by tracheotomy with soft-cuff TTs.'^ Mod- 
erate or greater mucosal inflammation and/or edema, and 
frank mucosal ulceration were both observed in 9 (41 %) of 
these patients. '2 

Mucosal ulceration is attributed to excessively high lat- 
eral tracheal wall pressure exerted by the cuff of the 
77-126,127 Mechanical forces exerted by a TT on the tra- 
chea wall can be greater than those generated by an ETT, 
because, without the anchoring effect of the mouth (or and glottis, the forces are more directly transmitted 
to the trachea. Tracheal injury from TT is superimposed 
upon injury caused by ETT used prior to tracheotomy. 
This may account for the fact that mucosal cuff site ulcer- 
ation is more frequently observed in tracheotomy patients 
than in patients who only had endotracheal intubation. '^ 

Tracheomalacia. Tracheomalacia complicating short- 
term tracheotomy has been considered rare since the ad- 
vent of soft-cuff TTs. The finding of tracheomalacia should 
raise the possibility of other causes, such as neoplasm, 
radiation therapy, trauma, necrotizing tracheal infection, 
or polychondritis. 

Law et al performed fiberoptic bronchoscopy prior to 
decannulation, and observed a high frequency of tracheo- 
malacia in brain-injured adults with a mean of 4.9 months 
of intubation with TT.'^" Using fiberoptic bronchoscopy, 

they observed a malacial .segment with forced coughing or 
labored respiration only above the stoma in 19 (23%) of 81 
patients. The clinical importance of these observations and 
the mechanisms of tracheomalacia in this population and 
in the broader population of tracheotomy patients are not 
known. However, the authors recommend that all candi- 
dates for tracheal decannulation undergo anatomic exam- 
ination of the larynx and trachea beforehand.'-** 

Tracheal Granuloma. Mucosal granulomas can appear 
in the healing phase of tracheal injury at the level of the 
stoma, cuff site, or any area of mucosal ulceration. They 
are observed during bronchoscopy and are usually incon- 
sequential. Law et al found suprastomal tracheal granulo- 
mas in 45 (56%) of 81 patients with long-term TTs in 
place.'-** These lesions appeared to originate at the stoma, 
and were pedunculated or sessile. 

Tracheoesophageal Fistula. This rare complication of 
tracheotomy has been attributed to high cuff inflation pres- 
sure leading to necrosis of the tracheal and esophageal 
walls, often in the simultaneous presence of an indwelling 
esophageal tube. Erosion of the posterior tracheal wall by 
the TT tip and penetration by TT suction catheters also 
have been implicated in this severe injury.'-'' It can also 
occur from incision of the posterior tracheal wall during 
the tracheotomy operation.'** 

Stemmer et al recorded 5 ( 1 .2%) cases of tracheoesoph- 
ageal fistula in a series of 403 tracheotomies,'"' but in a 
review of 1,928 tracheotomies, only 3 cases (0.2%) were 
reported."^ In one prospective study of tracheotomy where 
103 patients were available for follow-up, Andrews and 
Pearson reported 2 ( 1 .9%) cases of tracheoesophageal fis- 
tula.'^'' However, many of the TTs used in that study were 
red rubber tubes with hard cuffs. In 1972, Harley reported 
44 collected cases of ulcerative tracheoesophageal fistula 
following tracheotomy and mechanical ventilation, and em- 
phasized the importance of avoiding motion between the 
tube and the patient in preventing this complication.'-"' In 
patients with burns, a high rate (9%) of tracheoesophageal 
fistula, as well as tracheal stenosis (11%) and tracheoar- 
terial fistula (3%), has been reported,'" suggesting that 
burn patients are at increased risk for severe tracheal ero- 
sive injuries. 

In the modem era of soft-cuff TTs, tracheoesophageal 
fistula appears to be very rare. A MEDLINE literature 
search found no reports of tracheoesophageal fistula as a 
complication of tracheotomy during the 1990s. In a con- 
.secutive series of 470 tracheotomies, no cases of tracheo- 
esophageal fistula were found.'-' CT has been recom- 
mended as the preferred method of diagnosis of 
tracheoesophageal fistula.' ^2- '" Without immediate surgi- 
cal intervention, tracheoesophageal fistula is considered to 
be uniformly fatal. '^^ 


Respiratory Care • July 1999 Vol 44 No 7 

Complications of Endotracheal Intubation and Tracheotomy 

Tracheovascular Fistula. Erosion of the tracheal wall 
into a surrounding major artery or vein is a catastrophic 
complication of tracheotomy. The thyroid arteries and veins 
and the innominate artery are most commonly involved. 
Fortunately, this complication is now exceedingly rare. 
Upadhyay et al found no cases of tracheoinnominate artery 
fistula in reviewing 470 tracheotomy operations performed 
between 1989 and 1992. '2-» 

Fistulas occur at the level of the stoma or the TT cuff.'"^ '* 
Many patients with this complication of tracheotomy are 
at special risk because of head and neck malignancy, ra- 
diation therapy to the neck, or other factors. 

Tracheoinnominate artery fistula, the most common and 
severe type of tracheovascular fistula, is a rare but usually 
fatal complication of standard tracheotomy"-''^'' or medi- 
astinal tracheotomy.'" Three (8%) of 36 tracheotomy- 
related deaths in a Veterans Administration patient popu- 
lation were caused by tracheal erosion into the innominate 
artery at the point where it crosses the trachea anterior- 
ly."*' Management of tracheoinnominate artery fistula con- 
sists of immediate digital compression of the innominate 
artery behind the sternum,"" cuff overintlation, mainte- 
nance of airway patency, and emergency surgical repair 
via median sternotomy. '3*''"' 

Incidental Dislodgment and Decannulation. Dislodg- 
ment of the TT occurs in up to 7% of patients, and can be 
life-threatening."'' A retrospective series by Upadhyay et 
al found tube dislodgment within 5 days of the operation 
in 8 (1.7%) of 470 cases. '^^ In our prospective series, 2 
(4%) of 5 1 tracheotomy patients experienced tube dislodg- 
ment, one on the operating table and the other in the ICU; 
cardiac arrest occurred in both cases.'- In one of 2 cases 
reported in another series, pneumothorax resulted from 
dislodgment of the TT.""* Tube migration into the 
subcutaneous tissue of the neck accounted for 2 deaths in 
one series of 403 tracheotomies.'"' These anecdotal expe- 
riences indicate that migration of the TT is an uncommon 
but potentially life-threatening complication of 

Pulmonary Complications. The problems that follow 
tracheotomy parallel those that follow endotracheal intu- 
bation (aspiration, pneumonia, retained secretions, and at- 
electasis). Both symptomatic and silent aspiration events 
are common in patients with TTs in place. Santos et al 
reported that all of 17 patients surviving prolonged intu- 
bation and tracheotomy displayed clinical evidence of as- 
piration.'"' In a recent study using videofluoroscopy. about 
50% of adult patients receiving long-term mechanical ven- 
tilation via TT displayed aspiration of feedings, and 77% 
of aspirations were silent.'^" Patients with TTs can aspirate 
blue dye placed on the tongue. In one study, 5 (25%) of 20 
patients with TTs displayed staining of tracheal secretions 

after methylene blue dye was placed on the tongue, in 
contrast to none of 30 patients with ETTs (p < 0.01).'"*' 
Abnormalities in deglutition have also been identified in 
patients with TT.'^ 

Torres et al found VAP in 13 (46%) of 28 tracheotomy 
patients who required mechanical ventilation for more than 
48 hours.™ Compared to patients with ETTs (relative odds 
ratio = 1 ), the relative odds ratio for VAP in patients with 
TTs was 3.05 (p = 0.0041).™ However, tracheotomy was 
not an independent risk factor for VAP in that study. Gold- 
stein et al reported that none of 1 24 patients developed pneu- 
monia as a direct complication of bedside U"acheotomy."^ 

Mechanical Problems with the Tracheotomy Tube and 
Cuff. In one report, airway obstruction (6 cases) was sec- 
ond to hemorrhage (10 cases) as a cause of death in a series 
of 36 fatal complications of the tracheotomy procedure."* 
The lumen of the TT can become obstructed by secretions, 
crusts, blood, or flaps of tissue, or by partial dislodgment. 

Complications During and Immediately After 

Difficult Removal of Tracheotomy Tube Due to Tight 
Stoma. A tight stoma can make decannulation pain- 
ful.'-*^ Otherwise, decannulation is usually uneventful. 

Late Complications After Decannulation 

Scar and Keloid. In a literature review. Chew and 
Cantrell found only one case of stomal keloid in 1,928 
tracheotomies."^ Cosmetic results are reportedly better 
with percutaneous dilational tracheotomy than conventional 
tracheotomy because of the smaller stoma. '■*■* Van Heum 
et al observed that 13 (20%) of 66 patients had scar re- 
traction after percutaneous dilational tracheotomy.'"''' 

Persistent Open Fistula. Persistent tracheocutaneous fis- 
tula is an uncommon event after decannulation. In one 
series, 2 (3%) of 66 patients followed after percutaneous 
dilational tracheotomy had this complication.'-''' In a ret- 
rospective study of 150 patients, 5 (3.3%) had tracheocu- 
taneous fistula.''''' Surgical repair may close the tract.'"'''-''' 

Tracheal Stenosis. Tracheal stenosis is the most com- 
mon and potentially serious late complication of tracheot- 
omy. Following decannulation. it occurs at the level of the 
stoma, cuff site, or TT tip. Our experience '^ and that of 
others'"**'-'-'-^ suggests that stenosis is more common at 
the site of the tracheotomy stoma, although one group has 
reported that cuff site stenosis predominates.'"** Scarring 
and stricture formation at the site of the incision into the 
anterior tracheal wall is responsible for post-decannulation 
tracheal stenosis. Accordingly, most tracheal stenoses af- 

Respiratory Care • July 1999 Vol 44 No 7 

s ^^y 

Complications of Endotracheal Intubation and Tracheotomy 

ter tracheotomy are located anteriorly or anterolaterally. 
Infection has also been implicated in the pathogenesis. 
Prospective studies suggest that the overall frequency of 
tracheal stenosis (of 25% or greater) following tracheot- 
omy is approximately 13% (see Table 3). 

Because of widely different definitions of stenosis, the 
reported frequency of stomal site tracheal stenosis ranges 
from 0% to 85%."- We observed tracheal stenosis (de- 
fined as a greater than 10% reduction in the transverse air 
column diameter on anteroposterior tracheal tomograms) 
in 9 (60%) of 15 adult patients after decannulation.'- Eight 
of the 9 stenoses occurred at the level of the stoma and one 
at the level of the cuff. Two of the 9 stenoses were severe 
(greater than 50%). and 1 patient died as a direct result of 
airway obstruction from tracheal stenosis. In another pro- 
spective study, Dane and King reported that 8% of survi- 
vors following decannulation required surgical repair for 
symptomatic stomal site tracheal stenosis.'-'' One patient 
in that series had an 80% stomal stenosis. 

Surgical resection and reconstructive surgery are nec- 
essary in severe cases of tracheal stenosis, and experience 
with techniques has advanced to the point that good 
surgical results are achieved in many cases.''"" Grillo et al 
reported good or satisfactory results in 94% of over 500 
surgically treated patients.''''' 

Tracheal Dilatation. Dilatation of the trachea is a rare 
but serious complication of tracheotomy and endotracheal 
intubation." ''^" Widening of the trachea at the cuff site 
while the TT is in place is reported to be a risk factor for 
severe tracheal damage resulting in tracheal stenosis or 


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rax 1972;27(3):338-352. 

131. Jones WG. Madden M, Finkelstein J, Yurt RW, Goodwin CW. 
Tracheostomies in burn patients. Ann Surg I989;209(4):471^74. 

132. Leeds WM, Morley TF. Zappasodi SJ, Giudice JC. Computed to- 
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133. Berkmen YM. Auh YH. CT diagnosis of acquired tracheoesopha- 
geal fistula in adults. J Comput Assist Tomogr I985:9(2):.302-.3()4. 

134. Silen W, Spieker D. Fatal hemorrhage from the innominate artery 
after tracheostomy. Ann Surg 1965:162(6): l(X)5-l 112. 

135. Mehalic TF, Farhat SM. Tracheoarlerial fi.stula: a complication of 
tracheostomy in patients with brain stem injury. J Trauma 1972: 

136. Jones JW. Reynolds M, Hewitt RL. Drapanas T. Tracheo-innomi- 
nate artery erosion: successful surgical inanagement of a devastat- 
ing complication. Ann Surg I976;184(2): 194-204. 



137. Maipang T, Singha S, Panjapiyakul C, Tolemckokchyakarn P. Me- 
diastinal tracheostomy. Am J Surg I996;17I(6):58l-586. 

138. Wright CD. Management of tracheoinnominate artery fistula (re- 
view). Chest Surg Clin N Am I996:6(4):865-873. 

139. Keceligil HT. Erk MK, Kolbakir F. Yildirim A, Yilman M. Unal R. 
Tracheoinnominate artery fistula following tracheostomy. Cardio- 
vasc Surg 1995:3(5):509-510. 

Elpem EH, Scott MG. Petro L. Ries MH. Pulmonary aspiration in 
mechanically ventilated patients. Chest 1994;I05(2):563-566. 
Lien TC, Wang JH. [Incidence of pulmonary aspiration with dif- 
ferent kinds of artificial airways. | Chung Hua I Hsueh Tsa Chih 
(Taipei) 1 992:49(5 ):348-353. 

142. Shaker R, Milbrath M, Ren J, Campbell B, Toohill R, Hogan W. 
Deglutitive aspiration in patients with tracheostomy: effect of tra- 
cheostomy on the duration of vocal cord closure. Gastroenterology 

143. Pavlin EG, Nelson E. Pulliam J. Difficulty in removal of tracheos- 
tomy tubes. Anesthesiology 1976:44(1 ):69-70. 

144. Ivatury R, Siegel JH, Stahl WM, Simon R, Scorpio R, Gens DR. 
Percutaneous tracheostomy after trauma and critical illness. J Trauma 

145. van Heurn LW, Goei R, de Ploeg I, Ramsay G, Brink PR. Late 
complications of percutaneous dilatational tracheotomy. Chest 1996; 
1 10(6): 1572-1576. 

146. Waldron J, Padgham ND, Hurley SE. Complications of emergency 
and elective tracheostomy: a retrospective study of 150 consecutive 
cases. Ann R Coll Surg Engl 1990:72(4):2l8-220. 

147. Berenholz LP, Vail S, Berlet A. Management of tracheocutane- 
ous fistula. Arch Otolaryngol Head Neck Surg 1992:118(8): 

148. Geffin B, Pontoppidan H. Reduction of tracheal damage by the pre- 
stretching of infiatable cuffs. Anesthesiology 1969:3 1(5):462^63. 

149. Grillo HC. Donahue DM. Post intubation tracheal stenosis. Semin 
Thorac Cardiovasc Surg l996:8(4):370-380. 

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151. Pecora DV, Seinige U. Prolonged endotracheal intubation (letter). 
Chest 1982:82(1): 130. 


Heffner: I wonder how we might 
weight the complications. I think it wa.s 
stated earlier that the clinical implica- 
tions of subglottic stenosis are greater in 
terms of the opportunity for repair, com- 
pared to tracheal stenosis. When we look 
at those proportions, even though we 
know they're coming from different 
studies, how could we possibly weight 
those proportions on the basis of clini- 
cal significance so we can find out which 
procedure would be preferred in terms 
of airway injury? 

Stauffer: From looking at these pa- 
pers, I don't think that we can assign 
a weight in terms of the associated 
morbidity and mortality. Clearly we 
need new information about the mor- 
bidity of laryngeal and tracheal steno- 
sis, I have little doubt that subglottic 
and glottic stenosis is a much more 
serious problem than bottleneck ste- 
nosis of the trachea, which can usu- 
ally be repaired with laser therapy or 
with resectional operations. However, 
1 would defer to the experience of oto- 
laryngologists and surgeons who have 
dealt with this personally. 

Bishop: One thing that's interesting 
to me is why only the occasional 
patient develops laryngeal stenosis, 
and most heal so readily. In dog 
studies, we maintained ETTs in dogs 
and scoped them on a regular basis. 
The tubes were sutured in place, but 
one dog chewed the suture and 
coughed out the tube. The next day 
when we looked at it, the very signif- 
icant ulcers that had been there a day 
or 2 before were already largely 
healed, I think that's what Gene Co- 
lice's study showed, as well — that 
complete healing took place in the vast 

Respiratory Care • July 1999 Vol 44 No 7 


Complications of Endotracheal Intubation and Tracheotomy 

majority of patients. It was amazing 
to me how quickly the mucosa healed 
in the vast majority of cases. One of 
the puzzles is why it should only be 
the rare patient who actually gets into 
trouble with scarring and stenosis. 


I. Colice GL. Resolution of laryngeal injury 
following translaryngeal intubation. Am Rev 
RespirDis 1992;145(2 Pt l):361-364. 

Reibel: 1 don't think it's just the 
folks who have mucosal injury. I think 
there have to be other factors involved 
and that one very significant factor is 
gastroesophageal reflux or laryngo- 
pharyngeal reflux. Koufman has writ- 
ten extensively on laryngopharyngeal 
reflux, and I think he's really on to 
something.''^ Two of the worst ste- 
notic problems I've ever encountered 
were both in women who had had very 
short intubations and were both symp- 
tomatic refluxers prior to their surgery 
and the development of their compli- 
cations. They'd never had treatment, 
and basically were at a Stage 4 steno- 
sis, with no airway. The best thing is 
to be aware of the problems and try to 
prevent them. If a patient will have an 
orogastric or nasogastric tube, try to 
use a small, soft tube. If you think it's 
going to be there for a while, think 
about doing a G-tube. If they have 
any history of reflux, treat them ag- 


1 . Koufman JA . The otolaryngologic manifes- 
tations of gastroesophageal reflux disease 
(GERD): a clinical investigation of 225 pa- 

tients using ambulatory 24-hour pH moni- 
toring and an experimental investigation of 
the role of acid and pepsin in the develop- 
ment of laryngeal injury. Laryngoscope 
1991;101(4 Pt 2 Suppl 53):l-78. 
2. Koufman J. Sataloff RT, Toohill R. Laryn- 
gopharyngeal reflux: consensus conference 
report. J Voice 1996;I0(3):215-216. 

Stauffer: Investigators have looked 
at a number of potential risk factors 
for laryngeal ulceration from endotra- 
cheal intubation, and there is contin- 
ued debate about the role of duration 
of endotracheal intubation in the 
pathogenesis of these ulcers. They can 
appear with very short-term intuba- 
tions; the shortest duration I have read 
about is 15 minutes. I've seen some 
case reports where patients were intu- 
bated for many weeks without evi- 
dence of ulceration. Yet, several pro- 
spective studies have concluded that 
duration of intubation is significant. 
Hypotension, corticosteroid therapy, 
gender, tube size, infection, move- 
ment, and other possible risk factors 
have been studied, but I don't think 
any conclusive remarks can be made 
about them. Still, I welcome Dr 
Reibel 's comment about the potential 
role of gastroesophageal reflux. We 
know that's a cause of hoarseness, and 
perhaps it plays a role in the patho- 
genesis of laryngeal ulceration. 

Heffner: We typically look at cer- 
tain "hard" outcomes that are easy to 
measure and appear important to us, 
such as survival and evidence of tra- 
cheal stenosis, but when we study dif- 
ferent, more subtle outcomes that are 
valued by patients, we often obtain 

different findings. I was impressed by 
one study of long-term nasotracheal 
intubation,' which measured the prev- 
alence of sinus symptoms, voice qual- 
ity, the ability to sing, and other pa- 
tient-centered outcome measures of 
complications from airway manage- 
ment. I was impressed with the high 
proportion of patients who reported 
subtle complications and the central- 
ity of these complications to their self- 
perceived quality of life. I wonder if 
you're aware of any other studies that 
looked at these types of outcomes. 


I . Holdgaard HO, Pedersen J. Schurizek BA. 
Melsen NC. Juhl B. Complications and 
late sequelae following na.sotracheal intu- 
bation. Acta Anaesthesiol Scand 1993; 


Stauffer: Colice reported that heal- 
ing of laryngeal injury from prolonged 
translaryngeal intubation occurs 
within 8 weeks, and parallels the res- 
olution of symptoms such as hoarse- 
ness.' So, laryngeal injury is revers- 
ible, but it takes time. 


1. Colice GL. Resolution of laryngeal injury 
following translaryngeal intubation. Am Rev 
Respir Dis I992;I45(2 Pt l):36l-364. 

Bishop: It's interesting that serious 
singers don't even want to be intu- 
bated for routine surgical procedures, 
because injury and some voice changes 
take place even in the brief period of 
the surgical procedure. 


Respiratory Care • July 1999 Vol 44 No 7 

The Effects of Tracheostomy Tube Placement on 
Communication and Swallowing 

Maxine K Orringer MA CCC-SLP 


Communication Skill Development 

The Effect of Tracheostomy on Communication Skill Development 
Assessment and Treatment of Communication Disorders 

Family Involvement in the Treatment Process 
Speaking Valves 
Other Options 
The Team Approach 
Feeding and Swallowing 

The Normal Swallow 

The Impact of the Tracheostomy on Feeding and Swallowing 
Tracheostomy Tubes and Aspiration 
Evaluation of Feeding and Swallowing 

[RespirCare 1999;44(7):845-853] Key words: tracheostomy, speaking trache- 
ostomy valve, communication, swallowing, aspiration, feeding. 


Communication Skill Development 

While the placement of a tracheostomy tube has signif- 
icant medical ramifications, both positive and negative, it 
also has equally significant effects on communication skill 
development and feeding. This review addresses the im- 
pact of the presence of a tracheostomy on the development 
of speech (the production of sound), language (compre- 
hension and production of words and sentences), and feed- 
ing abilities in children. We also discuss modes of assess- 
ment and intervention in these areas, and the team members 
involved. Perhaps the most important member of the team 
is the family, for whom the risks and benefits have the 
greatest impact. 

Maxine K Orringer MA CCC-SLP is affiliated with the Department of 
Audiology and Communication Disorders, Children's Hospital of Pitts- 
burgh, Pittsburgh, Pennsylvania. 

Correspondence: Maxine K Orringer MA CCC-SLP. Communication 
Disorders Department, Children's Hospital of Pittsburgh. 3705 Fifth 
Avenue at DeSoto Street. Pittsburgh PA 15213-2538. E-mail: 

Communication skill development begins at the mo- 
ment the newborn and parents meet. It is natural for par- 
ents to talk to their infants and to wait with great antici- 
pation for some type of vocal response. Each response is 
met with delight from the infant's family, which reinforces 
the child's continued vocalization. Great attention is paid 
to the month-by-month acquisition of new communication 
skills, from babbling, to jargoning, to using true words. By 
one year of age, children are adept at conveying a variety 
of messages. Prizant and Wetherby's 1990 article outlines 
Bruner's 3 categories of communicative intent that emerge 
by the end of the first year of life. Via verbal and nonver- 
bal means, children use signals for behavioral regulation 
(requesting objects and actions, and protesting), social in- 
teraction (requesting comfort, calling, greeting, showing 
off, requesting permission), and joint attention (comment- 
ing on an object, action, or event, and requesting informa- 
tion).' At this age the child is producing approximately 15 
words, and by age 2 is putting words together into sen- 
tences. Language learning is closely related to the devel- 
opment of emotional and cognitive skills.- As the child 
continues to acquire a variety of inter-related skills, speech 

Respiratory Care • July 1999 Vol 44 No 7 

6 '■: .-> 

Tracheostomy: Communication and Swallowing 

and language serve as the bridge to his or her intellectual 
and emotional development. 

The Effect of Tracheostomy on Communication 
Skill Development 

The acquisition of communication skills is a fragile pro- 
cess, which can be affected by a number of factors, in- 
cluding tracheostomy tube placement. Earlier diagnosis 
and intervention of airway obstruction in infants and new- 
boms have led to increased survival rates for this popula- 
tion. There are not only more children with tracheosto- 
mies, but the duration of tube placement has also increased, 
and tube placement is more likely to continue into the 
linguistic period (ie, the time when use of language, verbal 
and/or nonverbal should emerge), resulting in an extended 
period during which the tube inhibits communication skill 
development.^ Most researchers would agree that children 
with tracheostomies are at risk for delays in communica- 
tion skill development if therapeutic intervention is not 
provided,'' especially if the tracheostomy tube is placed in 
the pre-linguistic period,'' but there is some disagreement 
regarding the exact impact of the presence of a tracheos- 
tomy on communication skill development. Hill and Sing- 
er's 1990 study found that tracheotomized children with- 
out primary neurological disorders or mental retardation 
appeared to have articulation and expressive language def- 
icits, but developed receptive language skills commensu- 
rate with their overall cognitive abilities.^ Other research- 
ers have found that these children do have receptive 
language impairment, although to a lesser degree.* 

For many children, the underlying medical issues that 
necessitate the tracheostomy (eg, extreme prematurity, neu- 
rological disorders) also impinge on the child's develop- 
ment. At the most basic level, children receive tracheos- 
tomies for airway management, and may experience subtle 
episodes of hypoxia prior to or after tracheostomy place- 
ment.^ Neuromotor involvement, cognitive deficits, and 
social/emotional difficulties provide additional etiologic 
features contributing to possible delays. The need for me- 
chanical ventilation can further complicate this picture, not 
only by limiting the child's ability to vocalize, but also by 
requiring the child to adapt his speech rate to the ma- 
chine's ventilatory cycle and to learn to vocalize during 
the inspiratory cycle. Mechanical ventilation restricts the 
child's mobility and ability to engage in social interac- 
tions,'' which affects the development of communication 
skills and the child's motivation to use these skills. 

An important factor contributing to delayed speech and 
expressive language development in the tracheotomized 
infant may be his inability to vocalize (ie, the child is 
unable to pass air around the tracheostomy tube and up 
through the vocal folds, resulting in the inability to create 
voice), rhis is due in part to the fact that the child does not 

have the opportunity to practice vocalizing and developing 
the oral motor patterns necessary for sound production. If 
this vocal deprivation extends into the linguistic period (ie, 
when symbolic language is used), the child may experi- 
ence significant speech and language delays after decan- 
nulation.5 Other important parent-child interactions that 
occur early in the speech and language learning process, 
such as reciprocal sound play and imitation, may also be 
missing. Parents may stop talking to their babies when 
their own communication attempts are met with silence. 
This is a difficult time for parents. They wonder if their 
child will ever talk and what they can do to encourage 
communication skill development. According to Mac- 
Donald, "Communication is the universal tool families 
have to build relationships with children".' It is an impor- 
tant part of the speech-language pathologist's job to ad- 
dress these concerns and to encourage the continuation of 
parent-child communication through all available sensory 
channels. This is the beginning of the speech therapy pro- 

Assessment and Treatment of 
Communication Disorders 

While care should be taken not to overwhelm families 
of children with new tracheostomies, therapeutic interven- 
tion with a strong focus on parent education should begin 
as soon as the child is medically stable. The process begins 
with evaluation of the child's receptive/expressive lan- 
guage, ability to produce voice, vocal quality, resonance, 
and oral motor skills. When appropriate, feeding and swal- 
lowing abilities are also assessed. And finally, the child's 
medical status and overall cognitive and social develop- 
ment (including hearing and vision) must be taken into 
consideration. The evaluation is accomplished via a vari- 
ety of channels, including parental interview, ob.servation 
of the child, and administration of standardized evalua- 

Family Involvement in the Treatment Process 

Once the assessment is complete, the therapist can pro- 
vide family members with information and practical sug- 
gestions regarding speech/language development. This in- 
formation provides parents with a positive way of 
interacting with their child, and a means of nurturing de- 
velopmental gains. Parents can learn to identify nonvocal 
communication behaviors that are observable in infants 
during the first 8 to 10 months of life.' These behaviors, 
which communicate the infant's emotional or physiologi- 
cal state include changes in body tone, movement, and rate 
of breathing. By 12-24 months of age, children are com- 
municating via conventional gestures, including pointing, 
waving, reaching,' facial expression, eye contact or eye 


Respiratory Care • July 1999 Vol 44 No 7 

Tracheostomy: Communication and Swallowing 

Fig. 1 . Left: Passy-Muir Speaking Valve. Middle: Kistner Valve (no 
longer made). Right: Shiley Speaking Valve. 

aversion, and body posture, to convey pleasure as well as 
protest. Increasing parents' awareness of their child's non- 
verbal signals helps them become better "listeners." If the 
child is not yet using these skills, parents can be taught to 
stimulate nonverbal communication. By acknowledging 
and enhancing the infant or young child's natural commu- 
nication, we are providing him or her with the opportunity 
to develop interpersonal and cognitive skills as well. 

Additional skills that are prerequisite to expressive lan- 
guage development include social and purposeful play and 
turn-taking — skills that parents can nurture in the course 
of their daily interactions."' Parents can also be taught a 
variety of techniques to encourage both receptive and ex- 
pressive language development, including self-talk (talk- 
ing to the child about what he or she is doing with the 
child) and parallel talk (talking about what the child is 
doing). These techniques provide the child with meaning- 
ful language relevant to his or her world. 

Speaking Valves 

In older children who require tracheostomy, the issues 
may not be articulation or language development. These 
children may have difficulties producing clear voice or 
adequate vocal volume. A speaking valve can assist with 
these difficulties. By preventing air escape through the 
tracheostomy during exhalation, breath is channeled around 
the tracheostomy and up through the vocal cords, allowing 
for voice production. With a cuffed tracheostomy tube, the 
cuff must be deflated. It is extremely important to remem- 
ber that a child should never be left unattended when the 
speaking valve is in place. Secondary benefits of a speak- 
ing valve include decreased secretions and increased ol- 
faction, possibly because of redirection of air flow through 
the oral and nasal passages.** 

There are a number of types of speaking tracheostomy 
valves, including: the Passy-Muir (Passy-Muir Inc, Irvine, 

Fig. 2. Olympic Trach-Talk. During inspiration, a spring keeps the 
valve open. During expiration the valve closes. (Tube provided 
courtesy of Olympic Medical). 

California) (Fig. 1); Shiley (Mallinckrodt, Pleasanton, Cal- 
ifornia) (see Fig. 1); Olympic (Olympic Medical, Seattle, 
Washington) (Fig. 2); and the Montgomery (Stuart K Mont- 
gomery, Westborough, Massachusetts). These valves vary 
in regard to air resistance during inhalation and safeguards 
during exhalation.' For example, while it is not uncommon 
for valves to be ejected during coughing, the Montgom- 
ery's diaphragm partially opens to allow the forceful ex- 
halation to escape without blowing it off the trach hub. 

Not all children are candidates for a speaking valve. The 
use of a pulse oximeter during speaking valve trials is 
helpful in determining if the child can maintain adequate 
Oj levels. If the space between the tracheostomy tube and 
tracheal wall does not allow for adequate exhalation, or if 
the tracheostomy has been placed as a result of stenosis, 
the child can experience air trapping and respiratory com- 
plications, including pneumothorax and subcutaneous em- 
physema. One way to test for air trapping is to listen for a 
"puff of air when the speaking valve is removed. The 
"puff is created when air that could not be exhaled orally 
escapes via the tracheostomy. Other symptoms that should 
result in discontinuation of valve use include significantly 
increased heart rate, increased coughing, change in respi- 
ratory pattern or respiratory effort, or the child's report of 
discomfort.'" The valve can be used with some patients 
requiring mechanical ventilation (Fig. 3), but it is contra- 
indicated for patients with laryngeal and pharyngeal dys- 
function and those with very low lung compliance and 
increased airway resistance." These patients cannot re- 
ceive adequate ventilation when the cuff is deflated. 

Given the various factors that must be taken into con- 
sideration, the decision to use a speaking valve must be 
made by a team including the speech/language pathologist, 
otolaryngologist, and respiratory therapist. While families 
are often very anxious to begin using a speaking valve, it 
is important to keep in mind that a child can vocalize 

Respiratory Care • July 1999 Vol 44 No 7 

Tracheostomy: Communication and Swallowing 

Passy-Muir Tracheostomy 
Speaking Valve connects 
directly to 
tracheostomy tube 
with 15-mm hub 

Wide mouth short flex 
tubing slides over valve 

Adapter connects 
short flex tubing 
to respiratory line 

Valve placement 
with standard — 
swivel adapter 

Fig. 3. Passy-Muir Speaking Valve adapted for use with ventilated 
patients. (Figure courtesy of Passy-Muir Inc.) 

without the use of a speaking valve. Although cannula size 
is dependent on the child's respiratory needs, selecting the 
smallest cannula possible to meet those needs will aid the 
child in obtaining the best possible vocal volume and qual- 
ity. Even without a speaking valve, children requiring me- 
chanical ventilation are often better able to produce voice 
with the presence of a leak around the tracheostomy. Vo- 
calization during mechanical ventilation is produced on 
inspiration rather than expiration, as is normally the case. 

Other Options 

Another option for encouraging vocalization is digital 
occlusion of the tracheostomy tube. This technique is not 
appropriate in children for whom a speaking valve cannot 

be used. When appropriate, this is an especially good way 
of encouraging vocalization in small infants. The clinician 
listens carefully for the child to inhale and then covers the 
tracheostomy during exhalation (not just when at rest but 
also when laughing or crying), once again encouraging air 
to pass around the tracheostomy tube and through the vo- 
cal cords. It is important to feel the rhythm of the child's 
breathing and initially to occlude the tracheostomy only 
briefly. Stimulating the infant to laugh or coo during tra- 
cheostomy occlusion is very often the first means of hav- 
ing the child vocalize. Toddlers often will learn to simply 
drop their chins to occlude the tracheostomy and produce 
vocalizations. The "blue baskets" used to prevent a child 
from inadvertently interfering with breathing can be re- 
moved during therapy or periods of vocal stimulation. For 
some toddlers who refuse a speaking valve, digital occlu- 
sion of their tracheostomy is more successful, as they have 
complete control over when to occlude the trach. Because 
finger occlusion can result in infection, this technique might 
be most desirable for short-term use.'^ 

The use of esophageal voice is another communication 
option. While this is more commonly thought of in the 
adult population, normal children have been observed to 
experiment with the production of esophageal speech by 

The use of speaking tracks is yet another means of 
facilitating sound production in the tracheotomized child. 
A fenestrated tracheostomy has one large or several small 
holes on the outer curve of the tube, which allow air to 
escape from the tracheostomy and pass through the vocal 
folds to produce voice. These tubes can be cuffed or cuffless, 
with or without an inner cannula. Although the fenestrated 
tracheostomies are useful for some children, the fenestrae 
can become occluded with secretions that reduce air flow 
and increase airway resistance. When used with a venti- 
lator-dependent patient, the ventilator tubing can pull on 
the tube, causing it to rotate. With the change in position, 
the fenestra may become occluded by the tracheal wall. 
Fenestrated tracheostomies are not appropriate for patients 
with a history of aspiration.' 

There are also several varieties of cuffed tracheostomy 
tubes that allow the patient to speak with the cuff inflated, 
such as the Portex Trach-Talk Blue Line Tracheostomy Tube 
(Sims Portex, Keene, New Hampshire) (Fig. 4). These tubes 
have an additional small piece of tubing above the cuff 
that attaches to an external air source. This additional air 
is channeled through the vocal cords, producing voice. 
While this device is effective, the increased airflow can 
cause throat dryness and concomitant discomfort in some 

If the tracheostomized child is unable to vocalize or 
obtain adequate vocal volume, the use of a total commu- 
nication approach is required. Such an approach combines 
a variety of communication modalities, including natural 


Respiratory Care • July 1999 Vol 44 No 7 

Tracheostomy: Communication and Swallowing 

Fig. 4. Portex Trach-Talk Blue Line Tracheostomy Tube witli cuff 

gesture, sign language, facial expression, vocalization, and 
augmentative or alternative communication systems. Par- 
ents often are hesitant to have their children begin to use 
manual sign language, fearing that they will not learn to 
vocalize and use spoken language, and that many people 
will not be able to understand their child. It is my expe- 
rience that once the child is able to say a word intelligibly, 
the signed version of the word is abandoned. In regard to 
the child being understood by nonsigners, many of the 
early signs are iconic (ie, they look like the action they 
represent). For example, the sign for "drink" is made by 
pretending to hold a glass and drink. "Eat" is conveyed by 
touching fingers to the mouth. 

There are some distinct benefits to sign language: port- 
ability; absence of the maintenance functions required with 
electronic communication devices; signing can be used in 
places where electronic devices cannot (eg, swimming pool, 
bathtub); signing has no limit in regard to lexicon size, so 
it can expand at the child's rate of development; and par- 
ents can begin using sign at birth so that the child is 
exposed to manual communication in the same way that he 
or she is exposed to words. Children imitate the commu- 
nication models used in their environment,- and will model 
sign if vocalization is not an option available to them. 
While it is not uncommon to teach adapted signs to chil- 
dren with impaired fine motor skills, signing may not be 
an option for a child with extremely poor motor skills, as 
his or her productions may be unintelligible. In that case, 
another mode of communication should be selected. 

A communication system is augmentative if it supple- 
ments a child's communication efforts, or alternative if 
used in place of traditional spoken communication. The 
level of sophistication of the device depends upon the 
abilities and needs of the child (Fig. 5 and Fig. 6). Highly 
sophisticated computerized devices can be accessed via 
touch or a variety of switches, including optical head point- 
ers, pneumatic "sip and puff switches, or manual switches. 

Fig. 5. Speak Easy Communication Device. The device can be 
controlled by pressing individual touch pads or via svi/itch access. 
(Both the device and switch are products of Able Net Inc, Minne- 
apolis, Minnesota. Picture communication symbols used wth the 
permission of the Mayer Johnson Company, copyright 1 981 -1 998.) 

Fig. 6. Dual Clock Communicator (with the Say It Play It Switch 
Plate). The patient selects objects by depressing a switch that 
causes the hand to move until the patient stops the hand near the 
desired object. (Enabling Devices and Toys for Special Children 
Inc, Hastings-on-Hudson, New York). 

When activated, such devices generally speak a phrase or 
sentence. In some systems the patient or therapist can even 
select a voice appropriate for the patient. Such devices 
have a wide variety of applications, ranging from basic 
communication to high level "written" work that can be 
downloaded into a computer and printed. 

A less technical augmentative system might be as sim- 
ple as a communication picture book. The child commu- 
nicates by pointing to pictures to convey a message. For 
children who are unable to point, eye gaze can be used to 
select messages from a communication board. Such boards 
can be purchased or constructed from a clear piece of 
lucite. Pictures are mounted on the Incite board and the 
board is placed between the child and the communication 

Respiratory Care • July 1999 Vol 44 No 7 


Tracheostomy: Communication and Swallowing 

partner so that the communication partner can see, through 
the board, which picture the child looks at to convey the 
desired message. 

An electrolarynx can also be helpful when working with 
a child who is unable to produce voice. Typically in adults 
the electrolarynx is placed on the neck. It produces an 
audible tone that is shaped into speech sounds as the user 
mouths the words. Because it is sometimes difficult to find 
a comfortable place on a the child's neck for placement of 
the device, the use of an intra-oral adapter is preferable. 
This device not only allows the child to produce "voice" — it 
also provides the child with the oral motor component of 
speech so that after decannulation he has had practice with 
the movements required to produce speech. There are many 
obstacles to the use of this device. Many patients and 
parents do not readily accept this mode of communication 
because the voice produced by the electrolarynx is quite 
mechanical. Some practice is required in order for the 
patient to achieve intelligible speech with this device. 
Words must be spoken slowly and articulated precisely. 
Adequate strength to hold and activate the electrolarynx 
while coordinating its use with speaking is also necessary. 

The Team Approach 

While many of these issues can be addressed by a speech/ 
language pathologist, a team approach is critical in work- 
ing with the tracheostomized child. The physical therapist 
may need to work with the child to achieve appropriate 
positioning. This is crucial for children with neurological 
deficit, so that they can obtain optimal use of their hands 
for signing or activation of a switch-controlled augmenta- 
tive communication device. Good head positioning is nec- 
essary for a child to use eye gaze. The occupational ther- 
apist may need to provide splints or assist in switch 
selection. The respiratory therapist may need to adjust 
ventilator settings during therapy to accommodate in- 
creased activity. In-home nurses can become partners in 
the therapeutic process, encouraging carry-over of therapy 
goals into the daily environment. Most importantly, par- 
ents, through natural interactions with their child, can fos- 
ter the child's desire to communicate and use the new 
skills introduced by the therapists. 

More than one agency may be involved in providing the 
child's therapy and medical care. Coordination and com- 
munication between agencies and therapists are essential 
to assure an organized therapy program with complemen- 
tary goals. However, in designing a treatment program, the 
child's respiratory condition, neurologic status, tolerance 
for positioning/activity, and the effects of medications on 
the child's status must all be taken into consideration."* 
Once again, parents should be viewed as critical members 
of the treatment team, since they know their child best and 

can often provide invaluable insight into the needs and 
abilities of the child. 

An important component required to fully attend to a 
child's communication needs is the monitoring of hearing. 
Children with long-term tracheostomies are at risk for sen- 
sorineural or conductive hearing losses'^ and should be 
evaluated by a certified audiologist. Unidentified and un- 
remediated hearing loss provides yet another roadblock for 
the language-learning child. 

Feeding and Swallowing 
The Normal Swallow 

The swallowing process is divided into 4 phases.'* Dur- 
ing the oral preparatory phase food is presented into the 
oral cavity. Lip closure prevents anterior loss of the ma- 
terial while the velum rests against the base of the tongue 
to prevent posterior loss of the bolus. Food is transported 
by the tongue to the chewing surfaces of the teeth. Via 
rotary movement of the mandible and tongue, solid foods 
are broken down into pieces appropriately sized for safe 
swallowing. The masticated material is combined with sa- 
liva and formed into a cohesive bolus. The oral phase of 
the swallow is initiated when the tongue begins to trans- 
port the bolus to the posterior portion of the oral cavity. 
When the bolus passes the anterior faucial arches the oral 
phase is ended. At this point, the swallow is triggered, 
marking the beginning of the pharyngeal phase where the 
bolus is propelled into the pharynx. Now the velum ele- 
vates to prevent food from entering the nasopharynx. The 
vocal cords approximate, the epiglottis closes, the larynx 
moves anteriorly/superiorly and the cricopharyngeus re- 
laxes to allow the bolus to pass through into the esopha- 
gus. The esophageal phase occurs when the bolus passes 
through the cricopharyngeus and into the cervical esophagus. 

The Impact of the Tracheostomy on Feeding and 

The physical act of swallowing is neurologically and 
physiologically complex. Successful swallowing requires 
the coordination of as many as 3 1 pairs of striated muscles 
and 5 cranial nerves.'* Yet, for most children, develop- 
ment of feeding and swallowing skills occurs in a seamless 
progression along the feeding continuum, beginning with 
bottle feeding and ending with the introduction of table 
food at 1 2 months of age. While many children with tra- 
cheostomies experience no difficulty with feeding and swal- 
lowing, for others the presence of a tracheostomy may 
create obstacles resulting in dysphagia (ie, impaired ability 
to chew or swallow liquids and/or solids), aspiration, food 
refusal, and, ultimately, poor nutrition. 


Respiratory Care • July 1999 Vol 44 No 7 

Tracheostomy: Communication and Swallowing 

Presence of the tracheostomy interrupts normal glottic 
and subglottic air flow. This can result in decreased laryn- 
geal sensation and reduced cough effectiveness,'"' which 
affect swallowing as well as the ability to protect the air- 
way. Typically, expiration following completion of the 
normal swallow helps to clear residue remaining in the 
airway or pharynx. Breathing through the tracheostomy 
eliminates expiratory air flow through the pharynx, thus 
eliminating another protective mechanism. Insertion of a 
tracheostomy causes the larynx to be anchored in place, 
preventing normal anterosuperior laryngeal excursion dur- 
ing the swallow. The presence of ventilator tubing and/or 
a cuffed tracheostomy tube further impedes the upward 
movement of the larynx as the tubing provides extra weight 
and the cuff is dragged along the tracheal walls with each 
swallow.'^ Impaired laryngeal excursion may result in in- 
adequate protection of the airway and aspiration after the 
swallow has been completed. Excessive cuff pressures can 
result in stricture formation or tracheal dilatation at the 
level of the cuff, '** which can also affect swallowing. The 
presence of an open tracheostomy in an otherwise closed 
system affects the patency of the swallow by disrupting 
airway pressures. This airway pressure, generated by the 
base of the tongue on the bolus, assists with bolus move- 
ment through the pharynx and into the esophagus. Alter- 
ation in this pressure results in pharyngeal residue follow- 
ing the swallow.''' 

The medical disorders leading to tracheostomy place- 
ment can result in dysphagia, as can the medications used 
to treat the illness. Breakdown can occur during any phase 
of the swallow. In the oral preparatory phase, weak oral 
musculature in an infant can result in a poor lip seal around 
the nipple. This causes loss of formula anteriorly and in- 
sufficient ability to extract liquid from the bottle. In an 
older child, weak musculature can make chewing, bolus 
preparation, and transport difficult. If the child is unable to 
control the bolus, it may leave the oral cavity prematurely, 
spilling into the pharynx and possibly into the open air- 
way. During the pharyngeal phase, low tone can result in 
poor palatal elevation, causing nasopharyngeal reflux. Med- 
ications such as decongestants or antihistamines that cause 
xerostomia (dry mouth) may make bolus preparation and 
transport difficult. Conversely, medications that increase 
production of secretions may place children who aspirate 
at greater risk. 

Tracheostomy Tubes and Aspiration 

Patients with tracheostomy tubes are at significant risk 
for aspiration. The indicators of aspiration are coughing 
and choking during feeding, increased congestion during 
or after feeding, increased fussiness during feeding, fre- 
quent or persistent respiratory illnesses, persistent low grade 
fever, a wet vocal quality during or after feeding, or failure 

of the child to progress to the next developmental level of 
feeding. Very often, children are aware of their swallow- 
ing difficulties and will limit their diet to foods they feel 
they can manage safely. A child may prefer to stay with 
pureed baby food rather than progress to more highly tex- 
tured foods if he or she has experienced choking or diffi- 
culty swallowing with that consistency. Children who si- 
lently aspirate thin liquids (ie, they are not coughing or 
choking in reaction to aspiration) are often described as 
not liking to drink or as becoming fussy as soon as the 
bottle is presented. In these instances, food refusal may be 
the result of the child's attempt to protect his/her airway. 
Once again, the child's behavior must be viewed as a 
communication regarding his or her feeding and swallow- 
ing ability. If he or she is refusing a particular food con- 
sistency, it is important to explore the reason for that re- 

Evaluation of Feeding and Swallowing 

Assessment of a child's feeding and swallowing abili- 
ties is performed by a team of professionals, which may 
include a dietitian, physician, speech/language pathologist, 
occupational therapist, physical therapist, psychologist, 
and/or social worker. The evaluation begins with a thor- 
ough history of the child's medical, developmental, nutri- 
tional, oral motor, and feeding status. Next, a feeding ob- 
servation, often referred to as a "bedside assessment" is 
conducted. During this portion of the evaluation, the team 
observes the parents as they feed their child, noting the 
parents" technique as well as the child's responses. Only 
the oral preparatory phase can be observed in this situa- 
tion, beginning with observation of lip closure during drink- 
ing and clearing food from eating utensils. Buccal tone is 
noted because lax cheek muscles can result in food pock- 
eting in the buccal spaces, from which it can be aspirated 
later. Tongue and jaw movement are noted in regard to 
bolus preparation. 

Behavioral issues also are addressed during this assess- 
ment. Food refusal can result from oral hypersensitivity, 
possibly because of ongoing unpleasant stimulation such 
as frequent oral suctioning or prolonged tube feedings. 
Malnourished children might also be subjected to forced 
feedings because of a caregiver's anxiety regarding the 
child's need for calories and fluid. Food refusal may result 
from the child's negative association with feeding itself 
This is frequently the case with children who suffer gas- 
troesophageal reflux, who learn to associate feeding with 
vomiting and discomfort. Similarly, ventilator-dependent 
infants who have difficulty sucking find feeding uncom- 
fortable because of abdominal distention and the need for 
frequent burping.'' Behavioral feeding difficulties can also 
occur as a result of prolonged hospitalizations, chronic 
illness, and multiple feeders or care givers. Also, the lack 

Respiratory Care • July 1999 Vol 44 No 7 


Tracheostomy: Communication and Swallowing 

of air flow via the upper airway affects the olfactory aspect 
of feeding, which also may affect the child's willingness 
to eat. 

When children severely limit the quantity or variety of 
foods they are willing to consume, malnutrition can result. 
Compromised nutritional status affects the immune sys- 
tem, leading to recurrent illnesses, during which time the 
child requires (but is less likely to consume) increased 
caloric intake, thus worsening the child's nutritional sta- 
tus."* Malnutrition can also result in behavioral changes 
and weakness, which further hinder feeding. 

If aspiration is suspected, additional testing may be re- 
quired, because it is difficult to accurately determine the 
presence of aspiration during the clinical evaluation. In 
their 1988 study Splaingard et a!" compared clinicians' 
bedside diagnosis of aspiration to modified barium swal- 
low study results, and found that experienced clinicians 
significantly underestimated the presence of aspiration, ac- 
curately judging its presence only 42% of the time. The 
Evans blue dye test can be used as an initial screening 
procedure in this process. This evaluation is conducted by 
first suctioning secretions from the child's tracheostomy 
and oral cavity. If present, the cuff is deflated. The patient 
then swallows a small amount of methylene blue dye mixed 
with food or liquid. At varying intervals following intro- 
duction of the dye, secretions are suctioned via the trache- 
ostomy. The presence of the blue dye in the secretions 
does not indicate that oral feeding should be stopped im- 
mediately, but it does indicate that additional assessment, 
such as a modified barium swallow study, should be pur- 
sued. Due to the possibility of false-negative results and 
the lack of standardization, the efficacy of this assessment 
is in question by many researchers.'** While this evaluation 
can provide some insight into the presence of immediate 
aspiration, it is most useful when used in conjunction with 
careful clinical observation and a modified barium swal- 
low study. 

The clinical evaluation considers only the oral prepara- 
tory phase, whereas the modified barium swallow study 
evaluates the oral and pharyngeal phases as well. This 
dynamic video fluoroscopic evaluation differs from a reg- 
ular barium swallow in that an attempt is made to simulate 
normal feeding. The child is placed in an upright position 
(or position approximating that in which the child is typ- 
ically fed) and provided with a variety of food consisten- 
cies (combined with barium) under intermittent video flu- 
oroscopy. Food is presented in the manner typical for that 
child (eg, bottle, sippie cup, or spoon). This study seeks to 
determine both the presence and etiology of aspiration, 
which helps the clinician decide which food consistencies 
are safe and what additional variables can be manipulated 
to achieve safe feeding. The use of a Passy-Muir speaking 
valve has been found to improve the swallow and decrease 
aspiration.-" Light digital occlusion of the tracheostomy 2' 

may also have the same effect. Therefore, swallows may 
be evaluated both with and without a valve or digital oc- 
clusion, and compared during the modified barium swal- 
low study. 


Recommendations for treatment are based on the results 
of the clinical and video fluoroscopic assessments. Treat- 
ment may involve changing the order of food presentation 
(eg, alternating food and liquid to clear the residue in the 
mouth and pharynx and eliminate aspiration occurring af- 
ter the swallow), the position in which the child is fed, the 
equipment used to feed the child, and/or the rate with 
which food is presented. Altering the volume of each bite 
as well as the consistency or temperature of the child's diet 
is often necessary. Oral stimulation may be initiated to 
prevent or decrease oral hypersensitivity and the resulting 
food refusal. Such a program introduces pleasant stimula- 
tion to the oral cavity, using a variety of textures, temper- 
atures, and tastes of food if permitted. Again, parent train- 
ing is a critical part of this therapeutic endeavor, especially 
in children with behavioral feeding issues. Teaching par- 
ents techniques for safe feeding and indicators for possible 
difficulties helps to increase their level of confidence and 
decrease their anxiety around meal times. Review of the 
taped videofluorscopic examination is a helpful tool for 
teaching parents why particular recommendations have 
been made. 

Parents derive a sense of accomplishment and normality 
when they are able to nourish their children. However, 
there are times when safe feeding cannot be accomplished 
or nutritional requirements cannot be met via oral feeding. 
In these instances the use of an alternative means of feed- 
ing, such as a gastrostomy or nasogastric tube may be 
necessary. Tube feedings often result in improved nutri- 
tion and decreased respiratory illness, which promotes op- 
timal development. When possible, tastes of food for plea- 
sure and oral stimulation programming will continue to 
pave the way for subsequent introduction of feeding. 


Tracheostomy tubes can have a significant effect on the 
child's ability to acquire communication and swallowing 
skills. Early assessment, intervention, and parent educa- 
tion are critical in helping these children to achieve opti- 
mal performance in both areas. A team approach is nec- 
essary, with the child's parents being key team members. 


1 . Prizant M. Wetherby, AM. Assessing the communication of infants 
and toddlers: integrating a socioemotional perspective. Zero to Three 

2. Hall SS, Weatherly KS. Using sign language with Iracheotomized 
infants and children. Pediatr Nurs l989;L'5(4);362-.'^67. 


Respiratory Care • July 1999 Vol 44 No 7 

Tracheostomy: Communication and Swallowing 



Hill BP, Singer LT. Speech and language development after infant 
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young children. Int J Pediatr Otorhinolaryngol I985;9(2):l6.'i-I7l. 
Simon BM. Silverman McGowan J. Tracheostomy in young chil- 14. 

dren: implication for a.ssessment and treatment of communication 
and feeding disorders. Inf Young Children 1 989; 1(3): I -9. 15. 

Mallory GB Jr, Stillwell PC. The ventilator-dependent child: issues in 
diagnosis and management. Arch Phys Med Rehabil 1 99 1 ;72( I ):43-55. 1 6. 

MacDonald JD. Carrol JY. A partnership model for communicating 
with infants at risk. Inf Young Children 1992;4(3):2O-30. 17. 

Lichtman SW. Birnbaum IL, Sanfilippo MR, Pellicone JT. Damon 
WJ, King ML. Effect of a tracheostomy speaking valve on secre- 
tions, arterial oxygenation, and olfaction: a quantitative evaluation. J 1 8. 
Speech Hear Res l995;38(3):549-555. 

Fomataro-Clerici L, Zajac DJ. Aerodynamic characteristics of tra- 
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Jackson D, Albamonte S. Enhancing communication with the Passy- 
Muir valve. Pediatr Nursl994;20(2): 149-153. 

Manzano JL, Lubillo S, Henrique?. D, Martin JC. Perez MC, Wilson 20. 

DJ. Verbal communication of ventilator-dependent patients. Crit Care 
Med I993;2I(4):5I2-5I7. 21. 

Silverman McGowan J, Bleile KM. Fus L, Bamas E. Communica- 
tion disorders. In: Bleile, KM, editor. The care of children with 

long-term tracheostomies. San Diego: Singular Publishing Group; 

Kaslon KW, Grabo, DE, Ruben, RJ. Voice, speech and. language 
habilitation in young children without laryngeal function. Arch Oto- 
laryngol l978;l04(12):737-739. 

Ahmann E, Lipsi KA. Early intervention for technology-dependent 
infants and young children. Inf Young Children l991;3(4):67-77. 
Logemann, JA. Evaluation and treatment of swallowing disorders. 
San Diego: College Hill Press; 1983:18-26. 
Steven.son RD, Allaire JH. The development of normal feeding and 
.swallowing. Pediatr Clin North Am 1991 ;38(6): 1439-1453. 
Dikeman KJ. Kazandjian MS. Communication and swallowing man- 
agement of iracheotomized and ventilator-dependent adults. San Di- 
ego: Singular Publishing Group; 1997:243, 246. 
Higgins DM, Maclean JC. Dysphagia in the patient with a trache- 
ostomy: six cases of inappropriate cuff deflation or removal. Heart 
Lung l997;26(3):2l5-220. 

Splaingard ML. Hutchins B, Sulton LD, Chaudhuri G. Aspiration in 
rehabilitation patients: videofluoroscopy vs bedside clinical assess- 
ment. Arch Phys Med Rehabil 1988;69(8):637-640. 
Eibling DE, Gross RD. Subglottic air pressure: a key component of swal- 
lowing efficiency. Ann Otol Rhinol Laryngol l996;105(4):253-258. 
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the tracheostomy tube: a pilot study of effects on aspiration and 
biomechanics of the swallow. Head Neck 1998;20(l):52-57. 


Heffner: I wonder if you could re- 
view the protocol for reinitiating feed- 
ing for patients who have been recently 
extubated in the ICU. House staff of- 
ten follow the same approach they use 
for re feeding the bowel after surgery, 
starting with liquids and working their 
way up. What would you recommend? 

Orringer: I would definitely recom- 
mend not starting with liquids, in spite 
of the fact that that's what everyone 
does. People tend to think liquids are 
the easiest to handle, when in reality 
they are most difficult. I prefer start- 
ing with semisolids, but even before 
that, there are steps to make oral feed- 
ing easier, including reintroducing 
taste. With children, I start with lolli- 
pops or licorice whips or minuscule 
drops of liquid in the mouth for sen- 
sation and taste. Some patients are so 
prone to aspiration that any oral stim- 
ulation leads to increased secretions 
(salivation) and aspiration. If patients 
do well with this beginning, I move 
them on to a semisolid diet, but start- 
ing with liquids is asking for diffi- 

Thompson: Is there any reason to 
think adults would be different? 

Orringer: No. While you might 
not want to use lollipops and licorice 
whips with adults, there is no reason 
to expect adults to handle liquids well 
as their first exposure to oral intake 
after intubation. Liquid is just diffi- 
cult to handle. It's much more affected 
by gravity, and there isn't really any 
oral preparatory phase for liquids. It 
passes through the mouth straight to 
the oral phase. This makes it difficult 
to tolerate in patients of all ages. 

Durbin: Is there any worry in trying 
to feed patients with cuffed endotra- 
cheal tubes who are on full mechani- 
cal ventilation? Certainly, I've never 
seen a normal-swallowing study in 
anyone still intubated. Even though 
they look good clinically and wanted 
to eat, the study always shows enough 
abnormalities that everybody gets ner- 
vous. I always say "They've got a 
cuffed endotracheal tube, which pre- 
vents aspiration. No big deal." I find 
myself debating dietitians, nurses, and 
others about feeding. Is there really 
anything I can do to improve swal- 

lowing in intubated, ventilated pa- 
tients? If they're going to need venti- 
lation for weeks, should we even 
bother considering oral feedings? 

Orringer: We haven't fed patients 
with endotracheal tubes. My worry 
would be that if the patient is pocket- 
ing food on top of the cuff, there would 
be a risk of aspiration through the chan- 
nels that develop between the trachea 
and the edge of the cuff. We certainly 
expect to feed patients with tracheos- 
tomy tubes as soon as their general 
condition permits, again, beginning 
with soft solids. 

Heffner: We've fed some intubated 
patients orally. Our rationale is based 
on the ability of patients with long- 
term tracheotomy tubes to tolerate oral 
diets. We reserve oral feedings in the 
ICU for patients who can handle it. 
Examples include neuromuscular pa- 
tients with intact bulbar control, and 
ventilator-dependent patients with 
chronic obstructive pulmonary disease 
who are up in the chair and weaning 
with a tracheostomy in place. I think 
the potential for an oral diet is one of 
the subtle advantages of tracheostomy. 

Respiratory Care • July 1999 Vol 44 No 7 


Tracheostomy: Communication and Swallowing 

Durbin: I would say that the swal- 
lowing studies in those folks are usu- 
ally abnormal. They're always abnor- 
mal when they have a cuffed 
endotracheal tube or tracheotomy tube, 
and require positive pressure ventila- 
tion. This is in contrast to someone 
who can tolerate having the cuff de- 
flated and use a speaking device. 

Heffner: We try oral feeding in the 
manner you recommend, starting with 
a soft, water-soluble diet. If the pa- 
tient aspirates some quantities, no 
harm is done and we progress as tol- 
erated. We also sometimes have orally 
fed nasotracheally-intubated patients, 
although we now rarely nasotrache- 
ally intubate anyone. 

Stolier: You described the modified 
barium swallow, which I would re- 
gard as a subjective test in the sense 
that one looks at the bolus traversing 
the appropriate channels. Have there 
been any concordance studies — that is 
to say, 2 observers looking at modi- 
fied barium swallow, with agreement 
or disagreement of the conclusions? 

Orringer: Yes. Many. 

Stolier: How do they perform? What 
is the agreement rate? I've often won- 
dered in patients in whom they've been 
done serially by different examiners 
whether I'm truly seeing improvement 
or whether it's simply inter-observer 

Orringer: Most of the studies show 
good inter-observer consistency. At 
Children's Hospital of Pittsburgh we 
have good agreement between the ra- 
diologists and me. A paper on dys- 
phasia was published a few years ago 
that attempted to develop a rating scale 
of penetration of liquids into the air- 
way.' I hope to implement this scale 
at our institution because it will pro- 
vide a common language for every- 
one involved with these patients. This 

would be an improvement over 
whether "aspiration" means penetra- 
tion just to the tip of the epiglottis, 
into the supraglottic space, down to 
the cords, or into the lungs. 


I. Rosenbek JC, Robbins JA, Roecker EB, 
Coyle JL, Wood JL. A penetration-aspira- 
tion scale. Dysphagia 1996 Spring; 1 1(2): 

Thompson: Just to make sure it was 
clear, we have many patients who are 
chronically ventilated (chronic being 
defined as anywhere from a few 
months to forever) who are routinely 
eating normal foods. 

Durbin: My point is that if we use a 
normal swallowing study as the gold 
standard, we would never feed any- 
one. We have fed people who don't 
have normal swallowing studies, and 
some do well. 

Orringer: There are patients who 
don't do well on the study, but we 
also try to assess what they may be 
able to tolerate, then we advance them 
very carefully. It's not a perfect test, 
but it's the best way we have of as- 
sessing them and knowing where to 
begin. If fluid is difficult, it's very 
easy to hydrate patients with baby 
food, which is 80% water, and there 
are adult equivalents. So, in most cases 
we can feed patients something. 

Heffner: Also, I think there are sub- 
groups in the acute setting of their re- 
covery from respiratory failure under- 
going a prolonged weaning protocol 
who have a trach in place — if you care- 
fully assess and monitor them, you 
may be able to initiate feeding before 
they're off the ventilator. I think that, 
like speech, the ability to eat in the 
ICU is a very rewarding experience, 
and we've noticed a parallel tapering 
of sedatives and antidepressant agents 

as the patient begins to resume their 
normal functions. I 

Orringer: I think it calms everybody 
down. It calms the families and the 

patients. . 


Stauffer: What is the importance, if 
any, of coloring enteral feeding for- 
mulas with blue dye? What does it 
mean if we see blue dye in an endo- 
tracheal or tracheostomy tube aspirate? 
Should that finding alter our manage- 
ment? I 

Orringer: Finding blue dye usually 
means that the patient has reflux and 
is experiencing retrograde aspiration. 
An alternative is use of glucose oxi- 
dase strips, although I'm not sure 
they give any more information than 
the dye. 

Stauffer: My question is what do we 
do with the results? How does color- 
ing tube feedings blue compare with 
our clinical assessment of aspiration? 

Ritz: In our adult population, we do a 
lot of bedside blue dye tests on pa- 
tients who are being evaluated for as- 
piration risk with placement of 
fenestrae to the tracheostomy tube. I 
don't have any numbers, but you get 
blue dye out of the airway in trace-to- 
moderate amounts frequently. One of 
the bedside considerations is how good 
is their cough. The ability of the pa- 
tient to clear their own airway may be 
the more important bedside judge- 
ment. ^ 

Watson: I feel it incumbent upon me 
to comment that this whole discussion 
involves a piece of the well organized 
critical care system that can only be 
managed in a setting where one cen- 
tralizes and brings these resources to- 
gether. In the community hospital 
where I am, with 8 different ICUs, the 
concept of working up somebody for 
swallowing dysfunction is a bit of a 
joke. It isn't to say we don't have re- 
sources, but it's clear that, with one 


Respiratory Care • July 1999 Vol 44 No 7 

Tracheostomy: Communication and Swallowing 

chronically-ventilated child a month, 
we don't have the kinds of resources 
that a centralized pediatric critical care 
system can have. And it's an issue 
that should be addressed in the com- 
munity hospital environment. It's very 
difficult to bring these resources to- 
gether in that setting, and yet, it's very 

clear that it changes the lives and the 
feelings and attitudes of the people in 
the units — the adults who are nurtured, 
so to speak, by being managed and 
having their feeding addressed, and 
having their ability to speak addressed, 
as opposed to having that ignored, as 
with the children. 

Campbell: Just a follow-up to that. 
Something that we're doing at the 
University of Cincinnati is that the 
respiratory therapists now are respon- 
sible for doing the swallow assess- 
ments on the patients. So that's some- 
thing they can incorporate into their 




D EC EMBER 1 s'-J^ ,_J^ 9 9 

■ f 

Las Vecbas^ Nevada 


Respiratory Care • July 1999 Vol 44 No 7 


Decannulation: How and Where 

James F Reibel MD 




Downsizing and Capping 




[Respir Care 1999;44(7):856- 

cheotomy, tracheostomy. 

859] Key words: decannulation, evaluation, tra- 


Successful decannulation marks the completion of tra- 
cheotomy management. Contemplation of decannulation 
assumes resolution of the underlying condition that neces- 
sitated the tracheotomy. At this stage the patient must be 
able to protect the airway, clear secretions, and have no 
significant compromise of the airway. Additionally, there 
should not be other mitigating factors such as anatomic 
abnormalities or planned surgery that would make preser- 
vation of the tracheotomy tract desirable. '^ 


Generally healthy patients tracheotomized for airway 
control, and others tracheotomized for respiratory failure 
who have not required long-term ventilator support, usu- 
ally can be decannulated directly. Those patients who have 
required prolonged ventilation, patients with significant 
comorbidities, and children benefit from a more cautious 
approach. As the patient's progress allows weaning from 
mechanical ventilation, resolution of infiltrates, and de- 
crease in volume of secretions, planning for decannulation 
begins. Resumption of a more normal activity level estab- 
lishes the patient's ability to maintain adequate oxygen- 
ation and eliminate pulmonary secretions effectively, with- 

James F Reibel MD is affiliated with the Department of Otolaryngology, 
Head and Neck Surgery, University of Virginia Medical Center, Char- 
lottesville, Virginia. 

Correspondence: James F Reibel MD, Department of Otolaryngology, 
Head and Neck Surgery, University of Virginia Medical Center, Char- 
lottesville VA 22908. E-mail: 

out the need for frequent suctioning. Ingestion of an 
adequate oral intake to maintain nutrition without aspira- 
tion demonstrates ability to protect the airway. At this 
stage inspection of the airway to confirm an adequate lu- 
men is appropriate. 

Flexible fiberoptic endoscopy is easily performed at the 
bedside or in the clinic in the adult or adolescent patient. 
This equipment is portable and available in almost every 
hospital or specialty clinic (Fig. 1). The nose and upper 
airway are topically anesthetized, and topical anesthesia is 
also applied to the tracheal mucosa through the tracheot- 
omy cannula, which causes the patient to cough. The pa- 
tient should be advised of this in advance, and also advised 
that some of the anesthesia will be coughed up into the 
pharynx, resulting in the patient's ability to taste the an- 
esthetic. This will anesthetize the larynx, facilitating the 
fiberoptic exam of the larynx and subglottis from above. 

Once adequate topical anesthesia is obtained, the flex- 
ible fiberoptic scope (fiberscope) is introduced through the 
tracheotomy tube and the distal trachea is inspected. Care- 
ful note is made of the character and viscosity of secre- 
tions, lesions, or granulation at the tip of the tube. Cultures 
can be taken if the secretion is purulent. 

Next, the fiberscope is passed via the anesthetized naris 
to inspect the upper airway. Purulent nasal cavity secre- 
tions can be cultured. Inspection of the larynx discloses 
any lesions, and inspection during quiet respiration, pho- 
nation, cough, and sniff maneuvers notes any limitation of 
vocal fold mobility. The fiberscope is then passed through 
the glottis to inspect the subglottis and upper trachea for 
stenosis, granulation, or tracheomalacia. Provided the ex- 
amination is relatively normal to this point, the tracheot- 
omy tube can be removed and the trachea inspected during 


Respiratory Care • July 1999 Vol 44 No 7 

Decannulation: How and Where 

Fig. 1. Flexible fiberoptic scope and light source. 

quiet respiration, forced inspiration, and cough. Any dy- 
namic or fixed obstruction is noted. In otFierwise healthy 
patients, this examination will confirm an adequate airway 
to permit decannulation. Some patients will have stenosis 
or granulations requiring additional evaluation and treat- 
ment. These patients, and all children, '-^-^ require rigid 

Fig. 2. Ventilating bronchoscope in place, with anesthesia circuit 
connected to ventilation port. 

endoscopy under general anesthesia prior to attempting 

During the examination under anesthesia, the patient's 
larynx is examined directly during spontaneous ventilation 
to assess vocal fold mobility, as well as the presence of 

Fig. 3. A: Cup forceps and suction cannulas for endoscope-assisted removal of stomal granulation. B: Ventilating bronchoscope pushes 
granulation tissue into stomal tract, facilitating removal with cup forceps. 

Respiratory Care • July 1999 Vol 44 No 7 


Decannulation: How and Where 




Fig. 4. A: Stomal obturator with spacers. B: Stomal obturator with solid central core in place (arrows point to dilated retention flange) (These 
obturators are made by Olympic Medical Corporation, Seattle, Washington). 

any glottic lesions, such as granuloma or web. After com- 
pleting direct laryngoscopic examination, the ventilating 
bronchoscope is passed through the glottis, allowing in- 
spection of the subglottis and upper trachea to the level of 
the stomal margin. 

Provided the examination discloses an adequate lumen 
to this point, the tracheotomy tube is removed and the 
bronchoscope is advanced to examine the trachea to the 
level of the mainstem bronchi. Ventilation is maintained 
via connection to the ventilation port of the bronchoscope 
(Fig. 2). Purulent secretions can be cultured. Areas of 
stenosis and tracheomalacia can be "sized" with the bron- 
choscope and the length and cross-sectional extent of the 
lesion noted. Small stenotic bands, webs, or granulations 
can be treated at this time'-^-* (Fig. 3). Upon completion of 
rigid bronchoscopy, the tracheotomy tube is replaced un- 
der direct vision, the tube reconnected, and ventilation 
reestablished prior to removal of the bronchoscope. Any 
significant lesions identified by this examination require 
additional investigation (eg, computed tomography) prior 
to continuing with plans for decannulation. 

In some patients with neuromuscular impairment, the 
decision may hinge on their ability to consistently clear 
secretions. Bach and Saporito"* found that the ability to 
generate peak cough flow of 160 L/min successfully pre- 
dicts ability to clear secretions, and thus permits extuba- 
tion or decannulation. Peak cough flow determination is 

warranted for this patient group, since these patients will 
require closer monitoring and supervision in an in-patient 
setting during their decannulation trial. 


Decannulation of otherwise healthy adult and adoles- 
cent patients who meet all decannulation criteria does not 
require observation in a controlled setting. Children,'--' 
and adults with concerns about their ability to tolerate 
decannulation, are best observed as in-patients. This may 
not require hospitalization in an acute care setting, but 
appropriately skilled nurses, respiratory therapists, and phy- 
sicians must be immediately available if a nonacute care 
setting is chosen (eg, a rehabilitation unit). 

Downsizing and Capping 

In children'--' and in adults with concerns about their 
ability to tolerate decannulation, a protocol of downsizing 
and capping is usually employed. By the time decannula- 
tion is contemplated, most patients have already had their 
initial tube replaced by one of smaller caliber. If additional 
size reduction is desired, the tracheotomy tube is further 
reduced in size and the patient is observed under appro- 
priate monitoring and supervision. When the smaller tube 
is tolerated without difficulty, the tube is capped and the 


Respiratory Care • July 1999 Vol 44 No 7 

Decannulation: How and Where 

patient further observed during activity and sleep. Moni- 
toring children during sleep may require polysomnogra- 
phy if there is concern about obstructive apnea.^ Once the 
patient has shown the ability to tolerate the capped, down- 
sized tube, the tube can be removed and the tracheotomy 
wound covered with an occlusive dressing. Children should 
be observed for at least one additional night after decan- 
nulation, with special attention to observation during sleep. 
An alternative to this combined downsizing and capping 
method is a tube occlusion protocol described by Rumbak 
et al.*^ The criterion for successful decannulation in this 
protocol is the ability to tolerate breathing via a capped, 
fenestrated #8 tracheotomy tube. Inability to tolerate an 
occluded #8 tube leads to a repeat trial with an occluded 
#7 fenestrated tube. Ability to tolerate an occluded #7 
fenestrated tube also predicted successful decannulation. 
Since the Rumbak et al study dealt exclusively with adults, 
these results might not extrapolate to children, and this 
technique should be used with extreme caution and only in 
a controlled setting. 


Use of a stomal obturator represents a compromise in 
that the patient breathes totally via the nose and mouth, but 
the tract to the tracheal opening is maintained by an in- 
dwelling device (Fig. 4). This device can be used to pre- 
serve airway access for patients who will need to undergo 
additional surgical procedures, most commonly head and 
neck or maxillofacial operations. Obturation is useful for 
patients with obstructive sleep apnea treated by tracheot- 
omy. Patients with neuromuscular disease and severe 
chronic obstructive pulmonary disease are also appropriate 
candidates for stomal obturation and observation prior to 


Surgical closure is seldom required in the acute setting 
of decannulation. Direct surgical closure is occasionally 

advantageous for head and neck patients, because it may 
facilitate their speech and swallowing rehabilitation. More 
commonly, the tracheotomy wound is covered with an 
occlusive dressing and allowed to close secondarily, in 
order to avoid the expense of a second procedure. Given 
sufficient time, nearly every tracheotomy wound heals with 
an acceptable cosmetic result. Rarely, a tract will epithe- 
lialize and persist as a tracheocutaneous fistula. The epi- 
thelialized tract must be excised, the tracheal margins fresh- 
ened and closed, and the strap muscles re-approximated. 
The skin is usually not closed if the closure is not airtight. 


Most patients are anxious about removal of their tra- 
cheotomy tube. While eager to be rid of the device, they 
are concerned about the ability to breathe, clear secretions, 
and protect the airway upon removal of the tube. With 
careful assessment of clinical progress and endoscopic con- 
firmation of adequate upper and lower airway, decannu- 
lation can be planned and safely carried out with a high 
probability of success. For children and certain adults, 
decannulation is best carried out in a closely controlled 


1. Johnson JT. Reilly JS, Mallory GB. Decannulation. In: Myers EN, 
Stool SE. Johnson JT. editors. Tracheotomy. New York: Churchill 
Livingstone; 1985:201-210. 

2. Gray RF, Todd NW, Jacobs IN. Tracheostomy decannulation in chil- 
dren: approaches and techniques, l^aryngoscope 1998;108( 1 Pt 1 ):8-12. 

3. Merritt RM. Bent JP, Smith RJH. Suprastomal granulation tissue and 
pediatric tracheostomy decannulation. Laryngoscope 1997;107(7): 

4. Bach JR, Saporito LR. Criteria for extubation and tracheostomy tube 
removal for patients with ventilatory failure: a different approach to 
weaning. Chest I996;l 1 0(6): I. '566-1571. 

5. Rumbak MJ. Graves AE, Scott MP. Sporn GK. Walsh FW. Ander- 
son WM. Goldman AL. Tracheostomy lube occlusion protocol 
predicts significant tracheal obstruction to air flow in patients 
requiring prolonged mechanical ventilation. Crit Care Med 1997; 


Tliompson: How is it that patients 
can breathe through or around an oc- 
cluded tracheostomy tube (in the case 
of an adult) or a proportionately 
smaller one (in the case of a child)? It 
seems to me that this amounts to a 
plug occupying two thirds or three 
quarters of the airway. If there was 
ever trial by fire, this is certainly an 
example. Why do we use this as a test 

of readiness for decannulation? Why 
does it work? 

Reibel: The more recent pediatric 
papers'" try to size the lumen when 
they do the rigid endoscopy, and then 
they try to reduce the size of the tube 
they're going to leave in place to about 
50% of the tracheal lumen. If the child 
can breathe around the tube, tolerate 
normal activity, and clear secretions 
around that significant obstruction, the 

decannulation should be successful. In 
the adult studies, these were fenes- 
trated 7s and 8s, so the patients were 
breathing somewhat around and some- 
what through the fenestration as well, 
but your point is well taken. 


1. Gray RF, Todd NW. Jacobs IN. Tracheos- 
tomy decannulation in children: approaches 
and techniques.Laryngoscope 1998:108(1 Pt 

Respiratory Care • July 1999 Vol 44 No 7 


Dec ANNUL ation: How and Where 

2. Merritt RM, Bent JP, Smith RJ. Suprastomal 
granulation tissue and pediatric tracheotomy 
decannulation. Laryngoscope 1997; 107(7): 

Thompson: It's interesting to me 
that a 50% occlusion might be an in- 
dication for a tracheostomy, and here 
we're using it as a criterion for decan- 

Reibel: That's the point. Most tra- 
cheae, after a tracheotomy/tracheos- 
tomy, have some element of tracheal 
stenosis. I don't think surgeons would 
disagree with that. Fortunately, only 
when stenosis approaches 50% do pa- 
tients start to have symptoms. There- 
fore, what degree of tracheal stenosis 
after a tracheotomy/tracheostomy is 
clinically relevant? In terms of how it 
is going to affect management of the 
patient, probably 50% is the cut-off 
for most patients. 

Ritz: Fleming et al introduced a ma- 
nometer between the cap and the tra- 
cheostomy tube to measure the tra- 
cheal pressure.' It's a quick trial. If 
the pressure has exceeded more than 
10 cm HjO of positive or negative 
expiratory pressure, that's bad. But it's 
kind of a quick and dirty way to as- 
sess the tolerance of the patient to a 
capped, obstructing tracheostomy 


I. Fleming CM, Hirsch C, Martianson J, Am- 
brosi D, Holmes L, Johnson DC. Airway 
pressure in patients with three different 
speaking valves (abstract). Am J Respir Crit 
Care Med 1998;3:A307. 

Reibel: Have you had the occasion 
to use peak cough flows? Have you 
found it helpful? 

Durbin: Is that without the endo- 
tracheal tube, measuring that peak flow 
or with a fenestration tube, or with the 
cuff deflated? 

Reibel: These were in tracheostomy 
tubes or in endotracheal tubes. They 
were using this as a predictor for ei- 
ther decannulation of a tracheostomy 
tube or an endotracheal tube. 

Hess: We put in an endotracheal tube 
and think we have to put on a little bit 
of pressure support to overcome the 
resistance through the endotracheal 
tube, but now you're talking about a 
patient needing to be able to tolerate a 
pretty significant obstruction of their 
airway before you take out the trach 

Campbell: I would say that this is a 
test. It's not a maneuver to try to pre- 
pare the patient. It's just to assess their 
ability. We think we can do that as 
well without pressure support. 

Hurford : B ut we don ' t normally cap 
the endotracheal tube as a trial prior to 

Campbell: It' s not uncommon to let 
the cuff down and assess the leak, 

Hurford: Right, but you don't leave 
the tube capped for 24 hours, as many 
people do for a tracheostomy tube. 

Bishop: There' s a big difference, be- 
cause the larynx closes down around 
the endotracheal tube. A normal adult 
size trachea is 18 mm by 13 mm in 
terms of the largest dimensions, as I 
recall. So, it turns out that with a 7 
mm tube in there, we're really only 
very minimally affecting the resistance 
of it. The trachea is made to allow you 
to run hard for a mile. So that even 
with a very substantial occlusion of it, 
you ought to be able to handle it pretty 
well. As you pointed out, a 50% ob- 
struction will probably begin to affect 
someone functionally. If their minute 
ventilation isn't especially high, they 

can tolerate a short obstruction of even 
substantially more than 50%. 

Reibel: If you read between the lines 
in the pediatric literature, a lot of this 
is to psychologically prepare the pa- 
tient and family. Everybody wants to 
be rid of the device, but they've had it 
in for a while and are apprehensive 
about its removal. This is to give them 
psychological preparation that they are 
going to be able to breathe and clear 
their secretions adequately. Properly 
done, this is something that ought to 
be nearly 100% successful. 

Watson: Did I understand you to 
say that you'd do an endoscopy on 
every child that you decannulate? Is 
this recommended? 

Reibel: Yes it is. 

Watson: Is that the standard of prac- 
tice around the country, by your un- 

Reibel: Yes. It's in the literature in 
many places.'"^ 


1. Johnson JT, Reilly JS. Mallory GB. Decan- 
nulation. In: Myers EN, Stool SE, Johnson 
JT, editors. Tracheotomy (first edition). New 
York: Churchill Livingstone; 1985:201-210. 

2. Gray RF, Todd NW, Jacobs IN. Tracheos- 
tomy decannulation in children; approaches 
and techniques. Laryngoscope 1998;108 
(1 Pt 1);8-12. 

3. Merritt RM, Bent JP, Smith RJ. Suprastomal 
granulation tissue and pediatric tracheotomy 
decannulation. Laryngoscope 1997; 107(7): 

Thompson: I agree. It is our prac- 
tice, and every paper I've reviewed by 
pediatric otolaryngologists mentions 
endoscopy as a necessary preparation 
for decannulation. Among other prob- 
lems, granulation tissue that might 
cause difficulty at decannulation is of- 
ten present, and can usually be re- 
moved at the time of endoscopy. 


Respiratory Care • July 1999 Vol 44 No 7 

Artificial Airways: Conference Summary 

John E Heffner MD 

Practice Variation 
Rule of Rescue 
Resource Allocation 

Practice Guidelines and Algorithmic Care 
Outcomes Research 
Patient-Centered Investigations 
Critical Evaluation of Current Practices 
Costs of Care 
Technology Assessment 
Future Directions 

[Respir Care 1999;44(7):861-865] Key words: artificial airway, airway man- 
agement, practice variation, rule of rescue, resource allocation, practice guide- 
lines, outcomes research, patient-centered investigations. 


It is indeed a challenge to summarize in the brief time 
allotted the remarkable presentations we heard on airway 
management during these last 2 days. In considering a 
theme for my comments, I have focused on the recurring 
impression I had from the discussions that the upper re- 
spiratory tract is truly elegant in both its structure and 
function. We heard from Rich Branson that the upper air- 
way's tremendous efficiency for humidifying and warm- 
ing inspired gases surpasses our ability to simulate these 
functions with mechanical devices such as artificial noses. 
We heard from Maxine Orringer that the act of swallow- 
ing, which can transpire without our conscious effort, rep- 
resents the orchestrated interaction of 32 muscles and 5 
nerves. We also learned that verbal communication is one 
of the most important factors in developing and maintain- 
ing relationships with our families, communities, and care- 
givers. The larynx, as the source of phonation, facilitates 
the subtleties and nuances of communication necessary for 
interacting with the world around us in a meaningful way. 
It appears that the upper airway is not only an integral 

John E Heffner MD is affiliated with the Department of Medicine, Med- 
ical University of South Carolina. Charleston, South Carolina. 

Correspondence: John E Heffner MD, Department of Medicine. Medical 
University of South Carolina, Charleston SC 29425. E-mail: 
heffnerj @ 

element in respiratory function but also contributes to our 
personal sense of self. 

In view of the elegant design of the upper airway, it is 
alarming to consider its fragile nature. Jack Stauffer's ex- 
tensive list of airway complications related to tracheotomy 
and translaryngeal intubation underscores the considerable 
risk of serious sequelae from airway interventions. From 
this conference I have gained a greater sense of respect, 
caution, and humility for managing the airways of patients 
who require intubation and ventilatory support. 

It is fortunate that we have a rich diversity of medical 
specialties with an interest in caring for such an important 
structure as the upper respiratory tract. The content of the 
conference presentations emerges from decades of obser- 
vations recorded by general surgeons, anesthesiologists, 
speech therapists, nurses, intensivists, pulmonary physi- 
cians, and respiratory therapists, to name a few. Unfortu- 
nately, this diversity risks the sequestering of knowledge 
because of the limited forums that exist for specialists 
from different fields to share their unique expertise. For 
this reason, I congratulate the organizers of this conference 
for convening such a broad- based group of experts on 
airway support. 

Jamie Stoller set the tone of the conference and my 
summary comments in his review of the history of airway 
support. He outlined 3 millennia of advances in airway 
support, and blended these events with insights into the 
social and scientific evolution of medicine. He reminded 

Respiratory Care • July 1999 Vol 44 No 7 


Artihcial Airways: Conference Summary 

us of the challenges facing clinicians in noting the signif- 
icance of new clinical observations, translating these ob- 
servations into improved clinical care, and disseminating 
innovations. The challenges faced by early pioneers of 
airway support sound surprisingly contemporary, consid- 
ering our modem-day efforts to limit practice variation, 
disseminate clinical practice guidelines, and promote best 
clinical practices. 1 have borrowed concepts from Jamie's 
presentation to serve as the outline for my summary, which 
focuses on practice variation, outcomes research, consid- 
erations of cost-effectiveness, technology assessment, clin- 
ical decision analysis, and the future of improving airway 

Practice Variation 

In regard to practice variation, we learned from Bill 
Hurford that, outside of the operating room, 37% of intu- 
bation efforts have complications and 22% of emergency 
intubation efforts require 3 or more attempts before an 
airway is successfully placed. Our group discussions in- 
dicated that such high rates of complications would not be 
tolerated in the operating room. Also, intubation trays are 
often unreliably stocked in medical centers, so resuscita- 
tion teams are advised to bring their own airway kits to 
cardiopulmonary arrests. Ann Thompson taught us that 
cricothyroidotomy is contraindicated in pediatric-aged pa- 
tients, yet she receives referred children who have had this 
procedure performed. As Charlie Durbin points out, more 
standards exist for the manufacture of endotracheal and 
tracheostomy tubes than for ensuring their proper insertion 
and care. 

In attempting to understand the practice variation that 
surrounds airway management, we might consider how 
physicians develop their clinical approaches to care. Clem 
McDonald suggested several years ago that physicians tend 
to treat patients with personal, informal clinical "policies" 
derived from our personal knowledge and experiences de- 
veloped over years of trial and error.' We often adopt 
clinical practices that seem to work on average for most 
patients. This heuristic approach to health care slows the 
dissemination of innovation, delays widespread adoption 
of best clinical practices, and allows variations in practice 
to persist. 

Rule of Rescue 

I believe that an additional factor underlies variations in 
practice and standards for airway support. The "rule of 
rescue" permits health care providers to bypass informed 
consent when administering emergency life-saving care, 
such as intubation for respiratory failure. This "assumed 
con.sent" allows physicians to omit our usual pre-proce- 
dure practices of carefully explaining risks and benefits 

and assuring patients that every precaution has been taken 
to bring about the best possible clinical outcome. Unfor- 
tunately, the necessary omission of these patient-physician 
discussions under the time pressure of an emergency event 
creates a "do the best you can under the less than ideal 
circumstances" mentality in managing unstable airways. 
To improve clinical practices in airway support, we need 
to apply to emergency airway practices the high standards, 
safeguards, training requirements, accountability, and ex- 
pectations for satisfactory outcomes that are attached to 
intubation in the operating room and trauma room. Oth- 
erwise, we may perpetuate unacceptable variations in air- 
way support practices, which could lead to the following 
imaginary but not at all implausible scenario: 

A 68-year-old retired nurse anesthetist suffering an acute 
exacerbation of chronic obstructive pulmonary disease is 
admitted with severe dyspnea. 

Patient: "If I worsen during the night, who will intubate 

Physician: "I'm not sure, probably one of the house 

Patient: "Will the house officer be well trained and cer- 
tified in intubation?" 

Physician: "1 don't know." 

Patient: "How many intubations have they performed?" 

Physician: "1 don't know." 

Patient: "What are my chances for a quick and success- 
ful intubation?" 

Physician: "That's a good question." 

Resource Allocation 

Providing needed training and experienced personnel to 
guarantee a high likelihood that a capable caregiver will be 
available to initiate and maintain airway support requires 
the expenditure of money and redirection of health care 
resources. We have heard several times during the confer- 
ence that medical centers often balk at expending resources 
to improve emergency intubation services, because other 
worthy health care needs would go unfunded. When deal- 
ing with questions of resource allocation, we might con- 
sider an ethical technique that assists in .selecting among 
competing health care services for funding when resources 
are limited. This approach asks individuals who have not 
yet developed a condition that requires any of the health 
care services under consideration to value the relative im- 
portance of the different interventions. A healthy segment 
of the population, for instance, might be asked to order the 
relative importance of providing cardiac transplantation 
for adults with coronary artery disease versus chemother- 
apy for patients with Stage III lung cancer. 1 would suggest 
that this technique would rank high for resource allocation 
the need to provide access to personnel who can place 


Respiratory Care • July 1999 Vol 44 No 7 

Artificial Airways: Conference Summary 

emergency airways with an acceptable degree of success 
and expertise. 

Practice Guidelines and Algorithmic Care 

The first step in developing and applying this expertise 
requires health care providers to develop practice guide- 
lines that utilize standardized algorithms for intubation. 
Mike Bishop's presentation on his institution's approach 
to improving outcomes of intubation represents a model of 
algorithmic care. The features that ensure success in his 
approach are several. First, the algorithm provides an ex- 
plicit, exact, and unambiguous decision-tree. For instance, 
the exact number of minutes before intubation would be 
anticipated to be necessary is explicitly stated. Second, the 
guideline selects personnel on the basis of their demon- 
strated skills for intubation rather than on their background, 
formal training, or professional degrees. In this instance, 
anesthesiologists and respiratory therapists with skills and 
interest in intubation were selected for participation. Third, 
participating respiratory therapists were not assumed to 
maintain competency, but instead underwent ongoing mon- 
itoring of their intubation skills and outcomes. These ele- 
ments of preparation appear to improve the quality of per- 
formance, and seem applicable to other health care facilities. 

The role of respiratory therapists in participating in in- 
tubation protocols may engender concern on the part of 
some physicians regarding the dilution of expertise in air- 
way management. These concerns arise from questions of 
qualifications or from turf-related issues of alterations of 
traditional professional roles. As Jim Reibel pointed out, 
however, we "need to do what's best for the patient and for 
the institution as a whole, and relegate our turf issues and 
professional positions in our traditional approaches of the 
past to a lower level of concern." No specialty "owns" the 
airway; we need to muster the properly-prepared and avail- 
able personnel at the right points in time to improve air- 
way supportive care. 

As Charlie Watson pointed out, the specific content of 
institutionally-based guidelines may be less important than 
the fact that such guidelines exist. The process of health 
care providers coming together to develop and monitor 
guidelines has a quality-enhancing effect of its own. The 
content of guidelines put into practice can evolve as cli- 
nicians observe the guidelines' effects on clinical practice 
and refine the guidelines to achieve their intended goals. 
Charlie Watson also pointed out that health care quality 
oversight bodies increasingly expect the existence of for- 
malized quality-enhancing guidelines. 

Outcomes Research 

A discussion of clinical practice guidelines leads us from 
practice variation to outcomes research. The proceedings 

of this conference encourage us to limit unnecessary prac- 
tice and standard variation in airway management, but also 
to maintain our awareness of the individual patient' s unique 
clinical needs. The field of outcomes research emphasizes 
the importance of patient-centered approaches to studying 
the airway. In designing research studies, we should in- 
clude more than the traditional end points (survival, inci- 
dence of pneumonia, or risk for airway injury from various 
airway interventions). We should also include more qual- 
itative outcomes, such as patient comfort, ability to com- 
municate, and overall patient satisfaction with care in the 
context of their individual values and needs. 

Patient-Centered Investigations 

In terms of outcomes research, few patient-centered in- 
vestigations have occurred. We need to know the effects of 
tracheotomy on sedation use, patient mobility, the quality 
of verbal communication, and general patient well-being. 
Outcomes research also warns us about overgeneralizing 
our research conclusions and applying results of studies to 
all patient groups. We heard in the conference that the 
secretion-clearing endotracheal tubes have been shown to 
decrease risk for ventilator-associated pneumonia. Over- 
generalizing from this measured outcome would appear to 
dictate that these tubes should be put into general clinical 
practice. As Charlie Durbin warns, however, these tubes 
are stiffer than traditional endotracheal tubes and may 
present a greater risk for laryngeal injury. We need to 
measure all foreseeable outcomes — both beneficial and 
adverse — before we change our clinical approaches on the 
basis of emerging results. 

We also need to be careful not to assume that study 
results apply to all patient populations. The results of clin- 
ical trials often do not have sufficient power to determine 
if all patient subgroups in the study responded similarly to 
the study intervention. On the basis of this limitation, Dean 
Hess warns us not to overinterpret the observations from 
weaning studies that patients weaned with T-bars achieve 
extubation as soon as patients weaned by pressure support. 
An overinterpretation of these observations might suggest 
that the resistance of breathing through an endotracheal 
tube does not delay successfully weaning. However, there 
may be subgroups of patients with marginal ventilatory 
capacity who will fail weaning unless the work of breath- 
ing necessary to overcome tube resistance is supported by 
pressure support or some other intervention. Additional 
studies are needed to examine this specific question. 

Critical Evaluation of Current Practices 

This conference included the suggestion that we clini- 
cians tend to overgeneralize from our research or clinical 
experiences. This habit generates clinical shibboleths that 

Respiratory Care • July 1999 Vol 44 No 7 


Artificial Airways: Conference Summary 

often escape critical examination. We have heard of sev- 
eral poorly supported but entrenched clinical practices that 
have fallen aside when critically appraised. We were told 
in the past not to orally intubate patients with head inju- 
ries, but now learn that mask ventilation and nasotracheal 
intubation are associated with greater neck movement. We 
were told in earlier decades that nasotracheal intubation 
was the preferred route in critically ill patients, but now 
learn that oral intubation has a lower risk of nosocomial 
sinusitis. We were also told that nasotracheal intubation is 
contraindicated in patients with basilar skull fracture, but 
now learn that the risk from this route of intubation is 
negligible. This conference emphasizes the importance of 
critically evaluating our airway practices with scientifi- 
cally sound clinical and basic science investigation. 

Costs of Care 

Throughout the conference we focused on improving 
the quality of airway care, but we also emphasized the 
importance of considering the costs of care. At times our 
discussions have stated that various approaches are or are 
not "cost-effective." We should clearly state the differ- 
ence, however, between the "cost-effectiveness" of care 
and efforts to minimize the cost of doing business for our 
health care institutions. Health care economists tell us to 
describe health care interventions as being cost-effective 
only if rigorous cost-effectiveness evaluations have been 
performed. This conference has illuminated the fact that 
very little in-depth cost-effectiveness research has been 
performed in the field of airway management. 

Also, to determine if a clinical approach is "cost-effec- 
tive" we need to know whose perspective is being used. 
Health care economists argue that it is necessary to take 
the societal perspective to perform cost-effectiveness eval- 
uations. We need to capture all of the costs assumed by 
society for the health care interventions and their conse- 
quences. The limited perspective of the health care insti- 
tution, an insurer, or a managed care organization may be 
warranted in developing budgets and considering profits, 
but has little to do with the determination of whether an 
approach to airway care is cost-effective. We need to fos- 
ter more cost-effectiveness research in airway manage- 
ment, to balance the cost minimization strategies of our 
health care institutions. The results of this research should 
be disseminated so that patients can determine if health 
care institutions have too much interest in decreasing costs 
by their resource allocation decisions and not enough in- 
terest in promoting best patient outcomes. 

Technology Assessment 

In discussing airway management, this conference also 
emphusi/ed that we clinicians need to learn more about 

technology assessment. How do we evaluate and balance 
potential benefit and risk from the infiltration of new tech- 
nology into our airway management approaches? When 
have sufficient clinical practice and investigational work 
been achieved to determine if new technology can be con- 
sidered "safe?" We have heard in the conference that per- 
cutaneous dilational tracheotomy has been determined to 
be as safe as standard surgical tracheotomy, yet Jack 
Stauffer clearly described the limitations of the long-term 
follow-up studies that examined the safety of percutaneous 
dilational tracheotomy. Perhaps we need to develop a "post- 
marketing" safety surveillance program akin to how drugs 
are examined after they achieve Food and Drug Adminis- 
tration approval. 

Much of the foregoing discussion can be considered to 
contain elements appropriate for examination by clinical 
decision analysis. Many approaches to airway control can 
be directed by simple maxims or rules, such as "do not 
perform cricothyroidotomy in children" or "maintain en- 
dotracheal cuff pressures within defined parameters." Many 
problems pertaining to airway control, however, are com- 
plex and defy simple maxims and rules. Individual clini- 
cians have difficulty analyzing these complex problems 
because we use simplifying strategies that limit the num- 
ber of variables considered. In approaching these complex 
problems, such as timing tracheotomy, we should better 
acquaint ourselves with formal approaches to decision anal- 
ysis that incorporate varying probabilities of benefit and 
risk with competing strategies of care. These approaches 
also consider the utility or value of the various outcomes 
from a patient-centered perspective. 

Future Directions 

While academic medical centers are challenged by the 
need to disseminate their airway discoveries to the hinter- 
lands of patient care, this conference has highlighted that 
many valuable observations in the form of performance 
improvement projects surface in community hospitals but 
are never published. How do we disseminate these discov- 
eries from the community hospital setting? Jamie StoUer's 


Effort and Resources Expended 

Fig. 1 . Trajectory of technological advances compared to resources 
expended. It becomes more difficult to improve the technology as 
a field matures. 


Respiratory Care • July 1999 Vol 44 No 7 

Artificial Airways: Conference Summary 

historical perspective outlines the trajectory of technology 
improvement in airway management over the last several 
centuries. As with all technology development, the benefit 
achieved from the resources expended tend to plateau as 
the field matures (Fig. 1). Perhaps in the coming decades, 
we need to place more effort on the dissemination of our 
cognitive and procedural skills in the form of guidelines 
and standards of care to improve outcomes in airway care. 
We also should not forget Ann Thompson's statement 
that "fundamentals are fundamentally important." Airway 
management is taking care of basics. It involves no glam- 
our or glitz, but often represents the important difference 

between a good clinical outcome and a catastrophic event. 
This conference is a point on the curve of progress that 
began with the ancient Egyptians and leads toward im- 
proved clinical application of fundamentally important best 
practices in airway care. The presentations in this confer- 
ence are a testimony to all of the clinicians and investiga- 
tors who continue to push us up along this curve. 


1. McDonald CJ. Medical heuristics: the silent adjudicators of clinical 
practice. Ann Intern Med 1996;I24(I Pt l):56-62. 

Respiratory Care • July 1999 Vol 44 No 7 


Listing and Reviews of Books and Other Media. Note to publishers: Send review copies of books, 
films, tapes, and software to Respiratory Care, 600 Ninth Avenue, Suite 702, Seattle WA 98104. 

Books, Films, 
Tapes, & Software 

Mechanical Ventilation: Physiological 
and Clinical Applications, 3"''' ed, Susan 
P Pilbeam MS RRT. Soft-cover, illustrated, 
460 pages. St Louis: Mosby, 1998. $42.00. 

This book covers 5 major asjjects of me- 
chanical ventilation. Part 1 addresses the 
basic concept of mechanical ventilation and 
is subdivided into 5 chapters, covering the 
history of resuscitation, intubation and early 
mechanical ventilation, arterial blood gas 
evaluation, basic concepts of mechanical 
ventilation, basics of ventilator graphics, 
and physical aspect of mechanical ventila- 

Part 2 describes monitoring in mechan- 
ical ventilation — noninvasive monitoring 
and hemodynamic monitoring of the ven- 
tilated patient. Effects and complications of 
mechanical ventilation, which delineate the 
physiologic effects and complication of pos- 
itive pressure ventilation are the subject of 
Part 3. 

Part 4 covers patient management in me- 
chanical ventilation in 8 chapters; estab- 
lishing the need for mechanical ventilation; 
selecting initial parameters and settings; 
special issues related to ventilator set up; 
basic patient assessment and methods to 
improve ventilation; methods to improve 
oxygenation; airways, circuits changes, 
medications, positioning, and other patient 
issues; problem-solving and troubleshoot- 
ing; and weaning and discontinuation. 

The final part addresses special tech- 
niques and patient populations, including 
subjects such as ventilatory support of new- 
bom and pediatric patients, home mechan- 
ical ventilation, and special techniques in 
ventilatory support. 

The book is directed primarily to stu- 
dents of respiratory therapy programs and 
nursing schools, and to respiratory thera- 
pists and nurses. It would also be useful for 
medical students and residents. Overall, the 
book meets its objective to serve as an ed- 
ucational tool for the intended readers. Each 
chapter is clearly presented and simple to 
read. At the end of each chapter, review 
questions highlight the important points. 
Decision-making and problem-solving are 
emphasized throughout the text. Answers 
to review and problem-solving questions 
are compiled at the end of the book 

and should prove very helpful for those read- 
ers who have to capture such a broad topic 
within a finite time. By and large the con- 
tents are up to date, and most recent cited 
references (1996) are only 2 years behind 
the publication date (1998). 

However, organization and accuracy of 
the topic presented could be improved in 
the next edition. Basic ventilator graphics 
could be consolidated in Part 2 on "Moni- 
toring in Mechanical Ventilation." In the 
chapter on "Noninvasive Monitoring in Me- 
chanically Ventilated Patients," the unit of 
work of breathing has to be clearly pre- 
sented either as Joules per breath or per 
liter of tidal volume. The chapter "Ad- 
vanced Steps in Arterial Blood Gas Eval- 
uation" needs to be presented in more pre- 
cise terms; the term "compensated" 
metabolic acidosis is inaccurate.'-^ 

Similarly, in the chapter on "Physiolog- 
ic Effects and Complications of Positive 
Pressure Ventilation," the major cause of 
oxygen-induced hypoventilation is not 
elimination of hypoxic drive.'* In the chap- 
ter on "Methods to Improve Oxygenation," 
shunt equation should be presented in a sim- 
ple manner. The derivation of the complex 
equation shown in the book should be 
presented. As written, the issue of "opti- 
mum posidve end-expiratory pressure," 
whether it was based on best oxygen trans- 
port, or lower inflection point on the pres- 
sure-volume curve, or both, can be con- 

For the most part, the figures are clearly 
presented, although there are a few omis- 
sions of labeling that may confuse those 
readers who are not quite familiar with me- 
chanics of breathing. I did not come across 
typographical error. 

In summary, this book meets its objec- 
tive for its intended readership. It has kept 
abreast with the recent rapid development 
in the field of mechanical ventilation, but 
some aspects of the subject need to be more 
accurately presented. 

Catherine Sassoon MD 

Pulmonary and Critical Care Section 

Veterans Affairs Medical Center 

Long Beach, California 


1. Haber RJ. A practical approach to acid-base 
disorders. West J Med 1991;155:146-151. 

2. Narins RG, Emmett M. Simple and mixed 
acid-base disorders: a practical approach. 
Medicine (Baltimore) 1 980;59(3): 1 6 1 -1 87. 

3. Aubier M, Murciano D, Fournier M, Milic- 
Emili J, Pariente R, Derenne JP. Central re- 
spiratory drive in acute respiratory failure of 
patients with chronic obstructive pulmonary 
disease. Am Rev Respir Dis 1980; 122(2): 

4. Sassoon CSH, Hassell KT, Mahutte CK. Hy- 
poxic-induced hypercapnia in stable chronic 
obstructive pulmonary disease. Am Rev Re- 
spir Dis 1987;135(4):907-911. 

Sleep Disorders Sourcebook, Jenifer Swan- 
son, ed. (Health Reference Series.) Hardback, 
439 pages. Detroit MI: Omnigraphics; 1999. 

Why do we sleep? Does exercise improve 
sleep? Is napping good or bad? What is sud- 
den infant death syndrome (SIDS)? Do we 
need less sleep as we grow older? What are 
effective treatments for sleep apnea? Are 
over-the-counter sleep medications safe? 
How do chronic illnesses affect sleep? If you 
have questions similar to these, where can 
you get the answers? The Sleep Disorders 
Sourcebook is a newly published reference 
source for health care consumers that answers 
these and other questions of interest. 

Sleep is something we all do, and some- 
thing that can also be disturbed at some time 
for most of us. Despite the relevance of sleep, 
the level of knowledge about it among health 
care providers and the public has been inad- 
equate. The Sleep Disorders Sourcebook, a 
compendium of previously published mate- 
rial, provides basic information about sleep, 
its disorders, and treatment options. 

The book is not bulky, has very readable 
type, and an excellent index. It is 421 pages 
long and consists of 53 chapters. The chap- 
ters are divided into 6 sections. "Understand- 
ing Sleep Requirements and the Costs of 
Sleep Deprivation" includes chapters on the 
biology of sleep and estimates and the con- 
sequences of sleep deprivation. "Sleep 
through the Lifespan" has chapters on SIDS, 
sleep disorders in children and older persons. 
"The Major Sleep Disorders" includes chap- 
ters on sleep apnea, narcolepsy, restless leg 
syndrome, and insomnia. "Sleep Medica- 


Respiratory Care • July 99 Vol 44 No 7 

Books, Films, Tapes, & Software 

tions" includes chapters on over-the-counter 
medications, melatonin, and benzodiaz- 
epines. "Sleep and Other Disorders" has 
chapters on mood disorders, chronic head- 
aches, and cancer. Finally, "Additional Help 
and Information" provides chapters on ad- 
ditional reading and resources on sleep dis- 

Individual chapters are derived from a 
variety of previously published material, in- 
cluding National Institutes of Health (NIH) 
publications, journal articles, and the pub- 
lications of major organizations concerned 
with sleep. The variety of sources for indi- 
vidual chapters is both a strength and a weak- 
ness of the book. It is hard to imagine that 
a book as comprehensive and authoritative 
could be derived from a single author. On 
the other hand, the use of different sources 
at times leads to some degree of redundancy, 
and the differing styles of writing in indi- 
vidual chapters could be disconcerting to 
someone who is reading an entire section or 
the entire book. For this reason, the book is 
probably best used as a reference to consult 
with questions on a specific topic rather than 
as a book to be read from cover to cover. 

The sources chosen for the individual 
chapters are for the most part excellent. The 
information presented is accurate and up to 
date with a few exceptions. Most of the 
chapters are easily accessible to an educated 
reader, though several chapters present in- 
formation at a level that is more appropriate 
to a health care provider. With its broad 
range of topics, the book achieves its mis- 
sion of providing basic consumer health in- 
formation to the health care consumer. 

It also has some value as resource for 
health care providers, including respiratory 
therapists, nurses, primary care physicians, 
and pulmonary specialists who deal with 
sleep-related disorders. It would be more 
appropriate for health care providers to con- 
sult standard sleep medicine texts for infor- 
mation on pathophysiology and treatment 
of major sleep disorders. Nevertheless, there 
are topics covered in this reference that are 
not always addressed adequately in these 
standard texts. Examples include the role of 
exercise in treating insomnia, the role of 
sleep disorders in chronic headaches, and 
the uses of melatonin in insomnia. The in- 
formation in these chapters could be useful 
in patient diagnosis, therapy, and education. 

The Sleep Disorders Sourcebook is a 
useful resource that provides accurate, rel- 
evant and accessible information on sleep 
to the general public. Health care providers 

who deal with sleep disorders patients may 
also find it helpful in being prepared to an- 
swer some of the questions patients ask. 

Vishesh Kapur MD MPH 

Division of Pulmonary and 

Critical Care Medicine 

Department of Medicine 

University of Washington 

Seattle, Washington 

Professional Ethics: A Guide for Reha- 
bilitation Professionals, by Ron Scott JD 
PT OCS. Soft-cover, 231 pages. St Louis: 
Mosby: 1998. $29.95. 

Professional Ethics: A Guide for Re- 
habilitation Professionals is a concise treat- 
ment of the varied issues .surrounding ethics 
for the health professional. The target audi- 
ence for this text is the rehabilitation pro- 
fessional, including the respiratory therapist. 
The text may also be useful to anyone in- 
volved in patient caie, including physicians, 
physician assistants, nurse practitioners, and 
others. Each chapter begins with a synopsis 
of the content presented in that chapter, 
which helps the reader establish a frame of 
reference for the material to be presented. 
Each chapter is neatly summarized. In ad- 
dition, a case presentation and questions with 
suggested answers follow each chapter — a 
format that challenges the learner to apply 
the concepts presented. 

The cases and questions have the poten- 
tial to .stimulate significant discussion among 
health care students and health profession- 
als. Although most of the cases presented 
use a physical therapy care setting, it would 
be easy enough to apply the scenario to a 
respiratory care situation. Each chapter is 
well referenced and a suggested reading list 
is offered. The chapters are presented in a 
logical order with each new chapter build- 
ing on the information presented in the pre- 
vious chapters. 

The book is written for the working pro- 
fessional but would also be appropriate for 
junior or senior heath care students. First 
and second year students may find the in- 
formation challenging if they lack the clin- 
ical exposure to appreciate the cases and 
concepts presented. Overall, the book is 
readable, and the author uses margin bullets 
in each chapter to highlight key points. The 
book is current and reminds us that profes- 
sional ethics have not changed, even in light 
of health care delivery changes brought on 
by managed care. 

Chapter 1 provides definitions for such 
ethical concepts as morals, ethics, and law. 
This chapter provides the basis for under- 
standing ethical concepts presented in sub- 
sequent chapters. The author accomplishes 
this through presentation of fundamental 
biomedical ethical principles and provides a 
basis for understanding legal duty. The chap- 
ter also demonstrates the concept that when 
a health care professional violates the law, 
he or she has also violated professional eth- 
ics. Several cases are woven into this first 
chapter to demonstrate the various legal and 
ethical concepts presented. The first chapter 
also utilizes .several charts that attempt to 
help the reader conceptualize the material. 
Some of these charts could have been im- 
proved by adding additional detail. For ex- 
ample, the author presents a rather simplis- 
tic model of a systems approach to ethical 
decision-making that could have been ex- 
panded to include intrinsic and extrinsic im- 
plications of various outcomes of decisions 

Chapter 2 provides a description of the 
terminology and language of various pro- 
fessional codes of ethics. The chapter es- 
tablishes the purpose or need for ethical 
codes among health care professions and 
describes the roles and responsibilities of 
organizations that develop codes of ethics. 
The chapter helps the reader differentiate 
between directive and nondirective language 
used in codes of ethics. The nondirective 
language is further broken down into state- 
ments of permissive and recommended con- 
duct, providing the reader with the detail 
necessary to interpret various written ethi- 
cal codes. The author then presents exam- 
ples of frameworks for codes of ethics from 
the fields of physical therapy, occupational 
therapy, and orthotics and prosthetics. The 
codes of ethics for other disciplines, includ- 
ing respiratory care, are presented in the 
appendixes of the text. The disciplinary pro- 
cesses for the 3 health fields included in this 
chapter are described. The disciplinary pro- 
cedures for other health fields are absent 
from both the chapter and the appendixes. 
The author does suggest student research 
into the judiciary policies of other disciplines 
with a challenge to compare their findings 
with those examples presented in the chap- 
ter. Due process is described and a chapter 
summary is provided. 

Chapter 3 tackles the ethical concerns of 
the health care professional as they relate to 
informed consent for interventions and re- 
search. The components of a complete and 

Respiratory Care • July 99 Vol 44 No 7 


Books, Films, Tapes, & Software 

ethical informed consent document are out- 
lined with excellent discussion of detailed 
subsections such as diagnostic findings, 
goals of the intervention, and potential as- 
sociated risks. The relationship between fail- 
ure to obtain informed consent and ethical 
decision-making is highlighted. The chap- 
ter relates the positive functional outcome 
potentials of an informed patient who un- 
derstands the objectives of the various in- 
terventions. The patient's "bill of rights" is 
presented and discussed as an ethical stan- 
dard to be upheld. The chapter then describes 
the emergency doctrine and therapeutic priv- 
ilege as exceptions to the requirement to 
obtain patient informed consent. This con- 
cept is supported with a brief case. Since 
respiratory therapists are usually members 
of the resuscitation team, this section is of 
great value, as are the next topics of "do not 
resuscitate" orders and "living wills." Fed- 
eral regulations regarding the use of human 
subjects in research settings are concisely 
described. The rationales for the federal reg- 
ulations are supported with historical focus 
on the Nuremberg Code and the Helsinki 
Declarations of 1964 and 1975. The chapter 
winds up with a discussion of the impact of 
managed care on the issues of informed con- 
sent — specifically, the "gag clauses" used 
by some managed care groups, which would 
limit full disclosure of treatment-related in- 
formation, which would, in turn, create an 
ethical dilemma. 

Chapter 4 covers the many issues regard- 
ing professional practice acts. The discus- 
sions and case examples regarding scope of 
practice encroachment under the current 
managed care framework are particularly 
useful and timely. After presenting back- 
ground on the development of, and estab- 
lishing the need for professional practice 
acts, the chapter describes the impact of 
"multiskilling" and cross-training on health 
care today. The ethical concepts of patient 
and provider responsibilities with respect to 
fees and payment for services are presented 
with special attention to "pro bono publico" 
service. Malpractice liability is presented as 
an ethical responsibility but also as a barrier 
to pro bono services. The chapter concludes 
with discussions of patient confidentiality 
issues, including patient information as well 
as proprietary information. Permissible and 
mandatory disclosures are explained, such 
as the release of information to third party 
payers. The chapter provides several mini- 
cases that enhance reader understanding of 
concepts presented. 

Patient and provider access issues are de- 
scribed in Chapter 5 with an initial review 
of the federal and state laws that facilitate 
specific groups' access to health care. Non- 
discrimination concepts are presented with 
regards to diagnosis-based bias, as well as 
provider concerns such as the Age Discrim- 
ination in Employment Act, Title I of the 
Americans with Disabilities Act, the Civil 
Rights Acts, and the Family and Medical 
Leave Act. The chapter concludes with a 
discussion of restrictive covenants in em- 
ployment contracts and the "any willing pro- 
vider" laws found in many states. As in pre- 
vious chapters, several mini-cases add to the 
understanding of the somewhat complex is- 
sues surrounding patient and provider ac- 
cess issues. 

Chapter 6 presents information related to 
professional business arrangements as they 
relate to ethical clinical practice. Ethical is- 
sues of conflict of interest, referral of pa- 
tients for profit, business contracts, adver- 
tising, and fraud and abuse are presented, 
with several cases used to elaborate on these 
important areas. Salient rules of conduct re- 
lated to the issues discussed are included. 

Sexual harassment and sexual miscon- 
duct are presented in Chapter 7. Sexual as- 
sault is clearly defined, and examples of 
ethical codes regarding sexual harassment 
or misconduct are discussed. Scott differen- 
tiates between provider-patient issues and 
harassment issues in the workplace. Em- 
ployer responsibilities regarding employer 
sexual harassment education are outlined. 
Scott includes a brief section on sexual ha- 
rassment and misconduct in the health pro- 
fessional education setting. 

In Chapter 8 Scott presents the legal and 
ethical implications surrounding the issue 
of life and death decision-making. Passive 
and active euthanasia are discussed, with 
terms such as "terminally ill patient" and 
"vegetative state" being clearly defined. The 
assessment of patient competency to make 
end-of-life decisions is considered, followed 
by a presentation of the ethical concerns 
regarding "do not resuscitate" orders. Ap- 
propriate legislation such as the Patient Self- 
Determination Act of 1990 is presented with 
an assessment of the impact of such acts on 
health professionals. "Living wills" and "du- 
rable power of attorney for health care de- 
cisions "are described, with examples from 
state statutes provided. The questions sur- 
rounding whether a constitutional right to 
die exists are addressed using United States 
Supreme Court case examples. The chapter 

concludes with a brief consideration of the 
issue of human cloning. 

The final chapter deals with the ethical 
issues surrounding the areas of research, ed- 
ucation, and patient care delivery. Subject 
protection in human research is discussed 
with examples from physical and occupa- 
tional therapy codes of ethics as they relate 
to research. Issues of disclosure, confiden- 
tiality, and informed consent are revisited. 
Student and faculty ethical responsibilities 
are presented as well as student-faculty in- 
teraction concerns. Scott states that the char- 
acteristics of the patient-client relationship 
also apply in the academic .setting. The au- 
thor presents a brief description of ethics 
committees of health care institutions and 
concludes Chapter 9 with the contrast be- 
tween the managed care paradigm and health 
care professional ethics, with mention of the 
changes in managed care that are being leg- 
islated or demanded by the public. 

Overall, the book is a comprehensive 
treatment of an increasingly complex sub- 
ject. Respiratory therapists will find the chap- 
ters relating to understanding the basics — 
informed consent, nondiscrimination 
regarding patient access, sexual harassment, 
life and death decision-making, and ethics 
in education and research — very useful. Of 
less use to the respiratory therapist aie the 
chapters regarding private practice and busi- 
ness arrangements. As the respiratory care 
profession evolves, the background provided 
related to private practice and business ar- 
rangements will become more applicable. 

The book is very timely, using current 
statutes, codes, and cases as examples. Chap- 
ter cases serve as an excellent tool for stim- 
ulating thought and understanding chapter 
concepts. The appendixes are extensive and 
provide support for the chapter content. The 
index is well structured and detailed. Since 
the author uses mostly physical therapy and 
occupational therapy examples in the text 
and chapter cases, the respiratory therapist 
would need to relate cases within our pro- 
fession to enhance his or her understanding 
and applicability of chapter concepts. A sup- 
plement of respiratory care-related cases 
would have been very helpful for the respi- 
ratory care educator. In the current and an- 
ticipated health care environment of man- 
aged care, this text would be a useful part of 
our respiratory care curriculum, as it orga- 
nizes and presents ethical concepts in a 
meaningful way. Physicians serving on in- 
stitutional ethics committees may find the 
contents useful; however, I feel the most 


Respiratory Care • July 99 Vol 44 No 7 

Books, Films, Tapes, & Software 

appropriate use of this book is in educa- 
tional programs, post-graduate course woric, 
workshops, or in the workplace. 

Ronald G. Beckett, PhD, RRT 

Respiratory Care Program 

Department of Cardiopulmonary Sciences 

and Diagnostic Imaging 

Quinnipiac College 

Hamden, Connecticut 

Introductory Medical Statistics, 3'''* ed. 

Richard F Mould. (Medical Science Series.) 
Soft-cover, illustrated, 403 pages. Bristol, 
UK and Philadelphia: Institute of Physics 
Publishing; 1998. $49.00. 

Introductory Medical Statistics is part 
of the Medical Science Series of books, 
which is the official book series of the In- 
ternational Federation for Medical and Bi- 
ological Engineering and the International 
Organization for Medical Physics. The text 
was initially based on a class taught to med- 
ical students, but its intended audience now 
includes all medical professionals — nurses, 
respiratory therapists, pharmacists, and phy- 
sicians. The editor of the new edition has 
made a number of significant additions that 
are essential in understanding the increas- 
ingly complex medical literature. The new 
additions include sections on epidemiolog- 
ical study design, survival analysis, multi- 
variate analysis, additional nonparametric 
tests, sensitivity and specificity, risk speci- 
fication, and analysis of treatment success. 

Chapters 1 and 2 are basic introductions 
to the pre.sentation and distribution of data. 
Chapter 3 introduces the concept of the nor- 
mal distribution. Chapters 4 through 7 dis- 
cuss sampling, followed by descriptions of 

the binomial and Poisson probability distri- 
butions. Chapter 8 introduces the concept 
of statistical inference. Chapters 9 through 
13 and Chapter 15 include the basic de- 
scription of statistical methods essential to 
any introductory text. These methods in- 
clude, chi-squared tests, Fisher's exact test, 
Student's /-test, McNemar's test, sign tests, 
log-rank, and Mantel-Haenszel tests. Chap- 
ters 16 and 17 address regression, correla- 
tion coefficients, and analysis of variance 
(ANOVA). Chapters 14 and 18 deal with 
survival analysis with the Kaplan-Meier 
method, life tables, and Cox proportional 
hazards models. Chapters 19 through 23 dis- 
cuss sensitivity and specificity, randomized 
and observational trials, assessments of treat- 
ment success, and risk specification. 

Overall, each chapter is well written and 
the text contains few typographical errors. 
The organization of the chapters generally 
follows a logical progression; however, as 
an introductory text, the Student's f-test is 
conceptually easier to understand and would 
seem more appropriate to precede the chap- 
ters on the chi-squared and Fisher's exact 
tests. It would also make more sense to group 
the survival analysis methods as a sequence 
of chapters after the discussions of regres- 
sion and ANOVA. As a "stand alone" text 
for a class on medical statistics, the material 
is generally complete and sufficient; how- 
ever, no additional exercises, aside from the 
worked examples, are included. If the pur- 
pose of a class were to learn the apphcation 
of statistical methods, this text would re- 
quire supplementation with additional exer- 
cises. The text is quite sufficient to give the 
reader an appreciation of the difficulties 
faced in the clinical literature. 

The author uses pragmatic and interest- 
ing examples from history, incorporating a 
good deal of humor and life into a subject 
matter that is often considered dull. More 
importantly, this approach makes the read- 
ing material much more engaging. The au- 
thors also stress the important distinction 
between statistical inference and declaration 
of facts, and point out the difference be- 
tween statistical significance and clinical 
"significance" (importance). The additional 
sections of this text are particularly valuable 
to the clinician. In particular, clinicians need 
to understand the difference between sensi- 
tivity and specificity and how they are re- 
lated to the positive and negative predictive 
value of a test. This text also provides the 
basic framework to help the reader under- 
stand the most common observational study 
designs and their limitations. The glossary 
of rates and ratios is a valuable resource to 
help make sense of confusing epidemiologic 
terminology. The sections on survival anal- 
ysis and specification of treatment success, 
cure, and quality of life are very appropriate 
and germane to clinical practice. 

Overall, this text is a valuable resource 
and would benefit any medical professional 
who wishes to gain a better understanding 
of the medical literature and biostatistics. 

David Au MD 

Senior Fellow 

Division of Pulmonary and 

Critical Care Medicine 

Department of Medicine 

University of Washington 

Seattle, Washington 


In the review by Michael W Prewitt PhD RRT of Critical Thinking: Cases in Respiratory Care. 

Kathleen J Wood MEd RRT. Soft-cover, 151 pages. Philadelphia: F A Davis Co; 1998. $23.95, and 

Instructor's Guide to Critical Thinking: Cases in Respiratory Care. Kathleen J Wood MED 

RRT with Lawrence A Dahl EdD RRT Soft-cover, 118 pages. Philadelphia: F A Davis Co; 1998 

[Respir Care 1999:44(3):367-368), the price of the Instructors Guide was incorrectly quoted as 


The Instructor's Guide is not a companion text and is not available for sale. It is a free resource 

available only to educators to help them in preparing their course. The Journal regrets the error. 

Respiratory Care • July 99 Vol 44 No 7 


News releases about new products and services will be considered for publication in this section. 

There is no charge for these listings. Send descriptive release and glossy black and white photographs 

to RESPIRATORY CARE, New Products & Services Dept, 1 1030 Abies Lane. Dallas TX 75229-4593. 

The Reader Service Card can be found at the back of the Journal. 

New Products 
& Services 

Drug Management System. Medtrac 
Technologies Inc launches MDILog'"''^ and 
PeakLogT^'^, an integrated pulmonary drug 
management system designed for chronic 
respiratory patients with conditions like 
asthma or COPD. According to Medtrac, 
this new system electronically monitors 
lung function, medication compliance, and 
patient technique and also provides treat- 
ment outcomes data. Company literature 
says the data can be downloaded to a PC 
for future reference. For more information 
from Medtrac Technologies, circle num- 
ber 153 on the reader service card in this 
issue, or send your request electronically 
via "Advertisers Online" at http://www. 

Ventilator has expanded the respiratory 
capabilities of the 740 Ventilator providing 
pressure control ventilation (PCV) as well 
as volume control ventilation (VCV) for 
mandatory breaths. The company also says 
the new device allows clinicians to set the 
rise time factor in PCV and pressure sup- 
port ventilation (PSV). Mallinckrodt says 
that the new ventilator also allows for 
adjustable flow sensitivity for PSV breaths 
and that VCV or PCV breaths are avail- 
able in apnea ventilation. For more infor- 
mation from Mallinckrodt, circle number 
1 54 on the reader service card in this issue, 
or send your request electronically via 
"Advertisers Online" at http://www. 

Ventilator. Mallinckrodt introduces the 
new Puritan-Bennett® 760'"^ Ventilator. 
A Mallinckrodt press says the 760 

Sleep Diagnostic System. Cadwell Lab- 
oratories introduces its Easy® II Sleep sys- 
tem. According to Cadwell, this new 
device offers full PSG capabilities with its 
simplified 32-channel Windows® 95/98 
recording and reviewing. A company press 
release says the system allows for the col- 
lection of virtually unlimited user-defin- 
able montages to perform PSGs at night 

and EEGs during the day. Cadwell says the 
Easy II system can be added to an exist- 
ing Windows 95 computer or a Dell com- 
puter can be purchased from Cadwell. For 
more information from Cadwell Labora- 
tories, circle number 155 on the reader ser- 
vice card in this issue, or send your request 
electronically via "Advertisers Online" at 

ICU Patient Speech Device. Sunrise Med- 
ical's DynaVox Systems introduces 
VitalVoice. Sunrise describes this new 
product as a communication device 
designed for ICU patients who are ven- 
tilated or are temporarily unable to speak 
for other medical reasons. According to 
the company, VitalVoice allows patients 
to choose from among many prerecorded 
messages or (especially for non-English 
speakers or small children) from among 
various icons. Sunrise says the device is 
equipped with a colorful touch-screen dis- 
play and high quality synthesized speech. 
For more information from Sunrise Med- 
ical circle number 156 on the reader ser- 
vice card in this issue, or send your request 
electronically via "Advertisers Online" at 



American Association for Respiratory Care 


Please read the eligibility requirements for each of the classifications in the 
right-hand column, then complete the applicable section. All information 
requested below must be provided, except where indicated as optional. 
See other side for more information and fee schedule. Please sign and date 
application on reverse side and type or print clearly. Processing of applica- 
tion takes approximately 15 days. 

D Active 

□ Foreign 

n Physician 

n Industrial ' 
D Special 
D Student 

Last Name _ 
First Name 

Social Security No. . 
Home Address 




Phone No. 

Primary Job Responsibility fcfieclr one only) 

n Technical Director 

n Assistant Technical Director 

n Pulmonary Function Specialist 

n Instructor/Educator 

Q Supervisor 

D Staff Therapist 

n Staff Technician 

□ Rehabilitation/fHome Care 

n Medical Director 

n Sales 

I D Student 

I n Other, specify 

Type of Business 

n Hospital 

D Skilled Nursing Facility 


n Home Health Agency 

D Educational Institution 

n Manufacturer or supplier 

n Other, specify 

Date of Birth (optional) 

Sex (optional) 

U.S. Citizen? 



Have you ever been a member of the AARC? 

If so, when? From 



For office use only 


An individual is eligible if he/she lives in the U.S. or its territories or v^^os on Active Member 
prior to moving outside its borders or territories and meets ONE of the follov/ing criteria: [1 ] is 
legally credentialed os a respiratory care professional if employed in a state that mandates 
such, OR [21 is a graduate or an accredited educationol program in respiratory care, OR [31 
holds a crecfential issued by the NBRC. An individual who is on AARC Active Member in good 
standing on December 8, 1 994, will continue as such provided his/her membership remains in 
good standing. 


Place of Employment 





Phone No. 

Medical Director/Medical Sponsor . 


Individuals who hold a position related to respiratory core but do not meet the requirements of 
Active Member shall be Associate Members. They hove all the rights and benefits of the Asso- 
ciation except to hold office, vote, or serve as chair of a standing committee. The following sub- 
classes of Associate Membership are available: Foreign, Physician, and Industrial [individuals 
whose primary occupation is directly or indirectly devoted to the manufacture, sale, or distribu- 
tion of respiratory care eauipment or supplies). Special Members are those not working in a 
respiratory core-related field. 


Place of Employment 




Phone No. 


Individuals will be classified as Student Members if they meet oil the requirements for Associate 
Membership and are enrolled in on educational program in respiratory care occredited by, or 
in the process of seeking accreditation from, on AARC-recognized agency. 

SPECIAL NOTICE — Student Members do not receive Continuing Respiratory Core Education 
[CRCE) transcripts. Upon completion of your respiratory core education, continuing education 
credits may be pursued upon your reclassificotion to Active or Associate Member. 

School/RC Program 




Phone No. 

Length of program 

n 1 year 
D 2 years 

Cxpe€ted Date of Graduation (REQUIRED 

□ 4 years 

D Other, specify . 



Preferred mailing address: ._ Home • . Business 
American Association for Respiratory Care . 11 030 Abies Lane • Dallas, TX 75229-4593 • [972] 243-2272 • Fax [972! 434-2720 

American Association for Respiratory Care 

embehship appucation 

Demographie Questions 

We request that you answer these questions in order to help us 
design services and programs to meet your needs. 

Cfiecit the Highest Degree Earned 

D High School 

D RC Graduate Technician 

D Associate Degree 

n Bachelor's Degree 

D Master's Degree 

n Doctorate Degree 

Number of Years in Respiratory Care 

□ a2 years □ 11-15 Years 

D 3-5 years n 1 6 years or more 

D 6-10 years 

Job Status 

n Full Time 

n Port Time 


n RRT 


n CRT 


n Physician 



n Perinatal/Pediotric 



n Less than $10,000 
D $10,001 -$20,000 
D $20,001 -$30,000 
D $30,001 -$40,000 
D $40,000 or more 


I hereby apply for membership in the American Association for Respiratory Care 
and have enclosed my dues. If approved for membership in the AARC, I v/ill abide 
by its bylavt/s and professional code of ethics. I authorize investigation of all state- 
ments contained herein and understand that misrepresentations or omissions of 
facts called for is cause for rejection or expulsion. 

A yeorly subscription to RESPIRATORY CARE journal and AARC Times magazine 
includes an allocation of $1 1 .50 from my dues for each of these publications. 

NOTE: Contributions or gifts to the AARC are not tax deductible as charitable con- 
tributions for income tax purposes. However, they may be tax deductible as ordi- 
nary and necessary business expenses subject to restrictions imposed as a result of 
association lobbying activities. The AARC estimates that the nondeductible portion 
of your dues — the portion v^hich is allocable to lobbying — is 26%. 



iMembersftip Fees 

Payment must accompany your application to the AARC. Fees are for 12 
montfis. (NOTE: Renewal fees are $75.00 Active, Associate-Industrial or Associ- 
ate-Pfiysician, or Special status; $90.00 for Associate-Foreign status; and 
$45.00 for Student status). 

n Active 

$ 87.50 

D Associate (Industrial or Physician) 

$ 87.50 

D Associate (Foreign) 


D Special 

$ 87.50 

D Student 

$ 45.00 



Spetialty Sections 

Established to recognize the specialty areas of respiratory care, these sections 
publish a bi-monthly newsletter that focuses on issues of specific concern to that 
specialty. The sections also design the specialty programming at the notional 
AARC meetings. 

n Adult Acute Care Section 


n Education Section 


D Perinatal-Pediatric Section 


n Diagnostics Section 


D Continuing Core- 

Rehabilitation Section 


D Management Section 


D Transport Section 


n Home Care Section 


n Subacute Care Section 




GRAND TOTAL = Membership 


plus optional sections 


n Total Amount Enclosed/Charged $ 
n Please charge my dues (see below| 

To charge your dues, complete the follov/ing: 
n MasterCard 
D Visa 

Card Number 

Cord Expires /_ 


Mail application and appropriate fees to: 
American Association for Respiratory Care • 1 1030 Abies Lane • Dallas, TX 75229-4593 

[972] 243-2272 • Fax [972] 484-2720 



Manuscript Preparation Guide 

General Information 

Respiratory Care welcomes original manuscripts related to the 
science and technology of respiratory care and prepared accord- 
ing to these Instructions and the Uniform Requirements for 
Manuscripts Submitted to BiomedicalJoumals [Respir Care 1997; 
42(6):623-634]. Manuscripts are blinded and reviewed by pro- 
fessionals who are experts in their fields. Authors are responsible 
for all aspects of the manuscript and receive galleys to proofread 
before publication. Each accepted manuscript is copyedited so that 
its message is clear and it conforms to the Journal's style. Published 
papers are copyrighted by Daedalus Inc and may not be published 
elsewhere without permission. 

Editorial consultation is available at any stage of planning or writ- 
ing. On request, specific guidance is provided for all publication cat- 
egories. To receive these Instructions and related materials, write 
to Respiratory Care, 600 Ninth Avenue, Suite 702, Seattle WA 
98104, call (206) 223-0558, or fax (206) 223-0563. 

Publication Categories & Structure 

Research Article: A report of an original investigation (a study). 
It includes a Title Page, Abstract, Introduction, Methods, Results, 
Discussion, Conclusions, Product Sources, Acknowledgments, Ref- 
erences, Tables, Appendices, Figures, and Figure Captions. 

Evaluation of Device/IVIethod/Technique: A description and eval- 
uation of an old or new device, method, technique, or modification. 
It has a Title Page, Abstract, Introduction, Description of De- 
vice/Method/Technique, Evaluation Methods, Evaluation Results, 
Discussion, Conclusions, Product Sources, Acknowledgments, Ref- 
erences, Tables, Appendices, Figures, and Figure Captions. Com- 
parative cost data should be included wherever possible. 

Case Report: A report of a clinical case that is uncommon, or was 
managed in a new way, or is exceptionally instructive. All authors 
must be associated with the case. A case-managing physician must 
either be an author or furnish a letter approving the manuscript. Its 
components are Title Page, Abstract, Introduction, Case Summa- 
ry, Discussion, References, Tables, Figures, and Figure Captions. 

Review Article: A comprehensive, critical review of the literature 
and state-of-the-art summary of a pertinent topic that has been the 
subject of at least 40 published research articles. Title Page, Out- 
line, Introduction, Review of the Literature, Summary, Acknowl- 
edgments, References. Tables, Appendices, and Figures and Cap- 
tions may be included. 

Overview: A critical review of a pertinent topic that has fewer than 
40 published research articles. 

Update: A report of subsequent developments in a topic that has 
been critically reviewed in this Journal or elsewhere. 

Point-of-View Paper: A paper expressing personal but substanti- 
ated opinions on a pertinent topic. Title Page, Text, References, Tables, 
and Illustrations may be included. 

Special Article: A pertinent paper not fitting one of the foregoing 
categories may be acceptable as a Special Article. Consult with the 
Editor before writing or submitting such a paper. 

Editorial: A paper drawing attention to a pertinent concern; it may 
present an opposing opinion, clarify a position, or bring a problem 
into focus. 

Letter: A signed communication, marked "For publication," 
about prior publications in this Journal or about other pertinent top- 
ics. Tables and illustrations may be included. 

Blood Gas Comer: A brief, instructive case report involving blood 
gas values — with Questions, Answers, and Discussion. 

Drug Capsule: A mini-review paper about a drug or class of drugs 
that includes discussions of pharmacology, pharmacokinetics, 
and pharmacotherapy. 

Graphics Comer: A briefcase report incorporating waveforms for 
monitoring or diagnosis — with Questions, Answers, and Discussion. 

Kittredge's Comer: A brief description of the operation of respiratory 
care equipment — with information from manufacturers and edito- 
rial comments and suggestions. 

PFT Corner: Like Blood Gas Comer, but involving pulmonary 
function tests. 

Cardiorespiratory Interactions. A case report demonstrating the 
interaction between the cardiovascular and respiratory systems. It 
should be a patient-care scenario; however, the case — the central 
theme — is the systems interaction. CRI is characterized by figures, 
equations, and a glossary. See the March 1996 Issue of RESPIRA- 
TORY Care for more detail. 

Test Your Radiologic Skill: Like Blood Gas Corner, but involv- 
ing pulmonary medicine radiography and including one or more radio- 
graphs; may involve imaging techniques other than conventional 
chest radiography. 

Review of Book, Film, Tape, or Software: A balanced, critical 
review of a recent release. 

Preparing the Manuscript 

Print on one side of white bond paper, 8.5 in. x 1 1 in. (216 x 279 mm) 
with margins of at least 1 in. (25 mm) on all sides of the page. Use 
double-spacing throughout the entire manuscript. Use a standard 
font (eg. Times, Helvetica, or Courier) at least 10 points in size, and 

RESPIRATORY CARE Manuscript Preparation Guide, Revised 2/98 

MANUSCRIPT Preparation Guide 

do not use italics except for special emphasis. Number all pages in 
upper-right comers. Indent paragraphs 5 spaces. Do not justify. Do 
not put authors' names, institutional affiliations or allusions to 
institutional affiliations in tlie text, or other identification any- 
where except on the title page. Repeat title only (no authors) on 
the abstract page. Begin each of the following on a new page: Title 
Page, Abstract, Text, Product Sources List, Acknowledgments, Ref- 
erences, each Table, and each Appendix. Use standard English in 
the first person and active voice. 

Center main section headings on the page and type them in cap- 
ital and small letters (eg. Introduction, Methods, Results, Discus- 
sion). Begin subheadings at the left margin and type them in cap- 
ital and small letters (eg, Patients, Equipment, Statistical Analysis). 

References. Cite only published works as references. Manuscripts 
accepted but not yet published may be cited as references: desig- 
nate the accepting journal, followed by (in press), and provide 3 copies 
of the in-press article for reviewer inspection. Cite references in the 
text with superscript numerals. Assign numbers in the order that ref- 
erences are first cited. On the reference page, list the cited works 
in numerical order. Follow the Journal's style for references. Abbre- 
viate journal names as in Index Medicus. List all authors. 

Article in a journal carrying pagination throughout volume: 

Rau JL, Harwood RJ. Comparison of nebulizer delivery methods 
through a neonatal endotracheal tube: a bench study. Respir Care 
1992;37(11): 1233-1240. 

Article in a publication that numbers each issue beginning with 
Page 1: 

Bunch D. Establishing a national database for home care. AARC Times 

Corporate author journal article: 

American Association for Respiratory Care. Criteria for establish- 
ing units for chronic ventilator-dependent patients in hospitals. Respir 
Care 1988;33(1 1): 1044-1046. 

Article in journal supplement: (Journals differ in their methods of 
numbering and identifying supplements. Supply sufficient information 
to promote retrieval.) 

Reynolds HY. Idiopathic interstitial pulmonary fibrosis. Chest 1986; 

Abstract in journal: (Abstracts citations are to be avoided. Those more 
than 3 years old should not be cited.) 

Stevens DP. Scavenging ribavirin from an oxygen hood to reduce envi- 
ronmental exposure (abstract). Respir Care 1990;35(1 1): 1087-1088. 

Editorial in journal: 

Enright P. Can we relax during spirometry? (editorial). Am Rev Respir 
Dis 1993;148(2):274. 

Editorial with no author given: 

Negative-pressure ventilation for chronic obstructive pulmonary dis- 
ease (editorial). Lancet 1992;340(8833):I440-1441. 

Letter in journal: 

Aelony Y. Ethnic norms for pulmonary function tests (letter). Chest 

Paper accepted but not yet published: 

Hess D. New therapies for asthma. Respir Care (year, in press). 

Personal author book: (For any book, specific pages should be cited 
whenever possible.) 

DeRemee RA. Clinical profiles of diffuse interstitial pulmonary dis- 
ease. New York: Futura; 1990. p. 76-85. 

Corporate author book: 

American Medical Association Department of Dmgs. AMA drug eval- 
uations, 3rd ed. Littleton CO: Publishing Sciences Group; 1977. 

Chapter in book with editor(s): 

Pierce AK. Acute respiratory failure. In: Guenter CA, Welch MH, edi- 
tors. Pulmonary medicine. Philadelphia: JB Lippincott; 1977:26-42. 

Tables. Use consecutively numbered tables to display information. 
Start each table on a separate page. Number and title the table and 
give each column a brief heading. Place explanations in footnotes, 
including all nonstandard abbreviations and symbols. Key the foot- 
notes with conventional designations (*, t, t, §, II, 1, **, tt) in con- 
sistent order, placing them superscript in the table body. Do not use 
horizontal or vertical rules or borders. Do not submit tables as pho- 
tographs, reduced in size, or on oversize paper. Use the same type- 
face as in the text. 

Illustrations. Graphs, line drawings, photographs, and radiographs 
are figures. Use only illustrations that clarify and augment the text. 
Number them consecutively as Fig. 1 , Fig. 2, and so forth accord- 
ing to the order by which they are mentioned in the text. Be sure 
all figures are cited. If any figure was previously published, include 
copyright holder's written permission to reproduce. Figures for 
publication must be of professional quality. Data for the original 
graphs should be available to the Editor upon request. If color is essen- 
tial, consult the Editor for more information. In reports of animal 
experiments, use schematic drawings, not photographs. A letter of 
consent must accompany any photograph of a person. Do not place 
titles and detailed explanations on figures; put this information in 
figure captions. If possible, submit radiographs as prints and full- 
size copies of film. 

Drugs. Identify precisely all drugs and chemicals used, giving gener- 
ic names, doses, and routes of administration. If desired, brand names 
may be given in parentheses after generic names. Drugs should be 
listed on the product-sources page. 

Commercial Products. In parentheses in the text, identify any com- 
mercial product (including model number if applicable) the first time 
it is mentioned, giving the manufacturer's name, city, and state or 
country. If four or more products are mentioned, do not list any man- 
ufacturers in the text; instead, list them on a Product Sources page 
at the end of the text, before the References. Provide model num- 
bers when available and manufacturer's suggested price, if the study 
has cost implications. 

Ethics. When reporting experiments on human subjects, indicate 
that procedures were conducted in accordance with the ethical stan- 
dards of the World Medical Association Declaration of Helsinki 
[Respir Care 1997;42(6):635-636] or of the institution's committee 

RESPIRATORY CARE Manuscript Preparation Guide, Revised 2/98 


on human experimentation. State that informed consent was 
obtained. Do not use patient's names, initials, or hospital numbers 
in text or illustrations. When reporting experiments on animals, indi- 
cate that the institution's policy, a national guideline, or a law on 
the care and use of laboratory animals was followed. 

Statistics. Identify the statistical tests used in analyzing the data, 
and give the prospectively determined level of significance in the 
Methods section. Report actual p values in Results. Cite only text- 
book and published article references to support choices of tests. Iden- 
tify any general-use or commercial computer programs used, nam- 
ing manufacturers and their locations. These should be listed on the 
product-sources page. 

Units of Measurement. Express measurements of length, height, 
weight, and volume in metric units appropriately abbreviated: tem- 
peratures in degrees Celsius; and blood pressures in millimeters of 
mercury (mm Hg). Report hematologic and clinical-chemistry mea- 
surements in conventional metric and in SI (Systeme Internationale) 
units. Show gas pressures (including blood gas tensions) in torr. 
List SI equivalent values, when possible, in brackets following non- 
Si values— for example, "PEEP, 10 cm H2O [0.98 1 kPa]." For con- 
version to SI, see RESPIRATORY CARE l988;33(IO):86l-873 (Oct 
1988), 1989;34(2):145(Feb 1989), and 1997;42(6):639-640 (June 

Conflict of Interest Authors are asked to disclose any liaison or finan- 
cial arrangement they have with a manufacturer or distributor whose 
product is part of the submitted manuscript or with the manufacturer 
or distributor of a competing product. (Such arrangements do not 
disqualify a paper from consideration and are not disclosed to review- 
ers.) A statement to this effect is included on the cover-letter page. 
(Reviewers are screened for possible conflict of interest.) 

Abbreviations and Symbols. Use standard abbreviations and sym- 
bols. Avoid creating new abbreviations. Avoid all abbreviations 
in the title and unusual abbreviations in the abstract. Use an abbre- 
viation only if the term occurs several times in the paper. Write out 
the full term the first time it appears, followed by the abbreviation 
in parentheses. Thereafter, employ the abbreviation alone. Never 
use an abbreviation without defining it. Standard units of mea- 
surement can be abbreviated without explanation (eg, 10 L/min, 
15 torr, 2.3 kPa). 

Please use the following forms: cm H2O (not cmH20), f (not bpm), 
L (not I), LVmin (not LPM, l/min, or 1pm), mL (not ml), mm Hg (not 
mraHg), pH (not Ph or PH), p > 0.001 (not p>O.OOI ), s (not sec), 
SpO: (pulse-oximetry saturation). See RESPIRATORY CARE: 
Standard Abbreviations and Symbols [RespirCare I997;42(6):637- 

Submitting the Manuscript 

Mail three copies [1 copy with author(s) name(s), affiliation(s). 2 
copies without name(s) and affiliation(s) for reviewers] of the manu- 
script, figures, and I diskette, and the Cover Letter & Checklist to 
RESPIRATORY CARE, 600 Ninth Avenue, Suite 702. Seattle WA 
98 104. Do not fax manuscripts. Protect figures with cardboard. Keep 
a copy of the manuscript and figures. Receipt of your manuscript 

will be acknowledged. 

Computer Diskettes. Authors are encouraged to submit electron- 
ic versions of manuscripts as well as printed copies (3.5 in. diskettes 
in Macintosh or IBM-DOS format). Label each diskette with date; 
author's name; name and version of word-processing program used; 
and filename(s). Software used to produce graphics and tables should 
be similarly identified. Do not write on diskette labels except with 
felt-tipped pen. If revision of a manuscript is required as a condi- 
tion of acceptance for publication, we ask that an electronic version 
of revision be supplied to facilitate copyediting and production. 

Prior and Duplicate Publication. Work that has been published 
or accepted elsewhere should not be submitted. In special instances, 
the Editor may consider such material, provided that permission to 
publish is given by the author and original publisher. Please con- 
sult the Editor before submitting such work. 

Authorship. All persons listed as authors should have participat- 
ed in the reported work and in the shaping of the manuscript; all must 
have proofread the submitted manuscript; and all should be able to 
publicly discuss and defend the paper's content. A paper with cor- 
porate authorship must specify the key persons responsible for the 
article. Authorship is not justified solely on the basis of solicitation 
of funding, collection or analysis of data, provision of advice, or sim- 
ilar services. Persons who provide such ancillary services exclusively 
may be recognized in an Acknowledgments section. 

Permissions. The manuscript must be accompanied by copies of 
permissions to reproduce previously published material (figures or 
tables); to use illustrations of, or report sensitive personal information 
about, identifiable persons; and to name persons in the Acknowl- 
edgments section. 

Reviewers. Please supply the names, credentials, affiliations, address- 
es, and phone/fax numbers of three professionals whom you con- 
sider expert on the topic of your paper. Your manuscript may be sent 
to one or more of them for blind peer review. 

Editorial Office: 


600 Ninth Avetiue, Suite 702 
Seattle W A 98104 

(206) 223-0558 (voice) 

(206) 223-0563 (fax) 


RESPIRATORY CARE Manuscript Preparation Guide, Revised 2/98 


A copy of this completed form must accompany all manuscripts submitted for publication. 

Title of Paper: 

Publication Category; 

Corresponding Author: Phone: FAX: 

Mailing Address: 

Reprints: □ Yes □ No E-mail Address: 

"We, the undersigned, have all participated in the work reported, proofread the accompanying manuscript, and approve its sub- 
mission for publication." Please print and include credentials, title, institution, academic appointments, city and state. If more 
than 4 authors, please use another copy of this form.* 

*First Author:. 

Author Signature/Date. 

'Second Author: 

Author Signature/Date. 

•Third Author: 

Author Signature/Date, 

*Fourth Author: 

Author Signature/Date, 

Has this research been presented in any public forum? □ Yes □ No 
If yes, where, when and by whom? 

Has this research received any awards? □ Yes □ No 
If yes, please describe. 

Has this research received any grants or other support, financial or material? □ Yes □ No 
If yes, please describe. 

Do any of the authors of this manuscript have a financial interest in (or a commercial or consulting relationship to) any of the 
products or manufacturers mentioned in this paper or any competing products or manufacturers? □ Yes □ No 

If yes, please describe. 

□ Have you enclosed a copy of the manuscript on diskette? 

□ Is double-spacing used throughout entire manuscript? 

□ Are all pages numbered in upper-right corners? 

□ Are all references, figures, and tables cited in the text? 

□ Has the accuracy of the references been checked, and are they correctly formatted? 

□ Have SI values been provided? 

□ Has all arithmetic been checked? 

□ Have generic names of drugs been provided? 

□ Have necessary written permissions been provided? : 

□ Have authors' names been omitted from text and figure labels? 

□ Have copies of 'in press' references been provided? 
G Has the manuscript been proofread by all the authors? 

□ Have the manufacturers and their locations been provided for all devices and equipment used? 

Respiratory Care Manuscript Preparation Guide, Revised 2/98 

Not-for-profit organizations are offered a free advertisement of up to eight lines to appear, on a space-available 

basis, in Calendar of Events in RESPIRATORY CARE. Ads for other meetings are priced at $5.50 per line and require 

an insertion order. Deadline is the 20th of the month two months preceding the month in which you wish the ad to run. 

Submit copy and insertion orders to Calendar of Events. RESPIRATORY CARE. 1 1030 Abies Lane, Dallas TX 75229-4593. 

of Events 


August 15-21— Cleveland. Ohio 
The OSRC state conference will be 
held at the Holiday Inn in 
Independence, just south of 
Cleveland. Specialty sessions include 
critical care, pediatrics, rehab/ 
continuing care, research, and 

Contact: Joe Huff at (216) 861-6200, 
ext. 3892, or 
Nancy Johnson at (330) 929-7166, 

September 8-10 — Hot Springs, 


The ASRC presemts its 28th Annual 
State Meeting and Education Seminar 
at the Hot Springs Hilton and 
Convention Center. Topics will 
include health care in Arkansas, 
patient rights, disease management, 
and case studies by area RTs. 
Scheduled to speak are State 
Representative Brenda Gullett, 
Congressman Vic Snyder, Tom 
Kallstrom of Cleveland, OH, ASRC 
President John Campbell. AARC 
President Dianne Kimball, and 

(Kristin McFall of Denver, CO (topic: 
cystic fibrosis). 

Contact: John Lindsey at (870) 541- 

September 16-17 — Pittsburgh, 

, Pennsylvania 

I The PSRC will host their 26th Annual 

Western Pennsylvania Regional 
Pulmonary Medicine and Physiology 
Conference at the Sheraton Station 
Square. Topics include management, 
critical care, sleep diagnostics, 

(pulmonary rehabilitation, and the 
physician forum. 

Contact: Debbie Logan at (800) 545- 
4663, ext. 112. 

September 24-25 — Cleveland, Ohio 
The AARC presents the "Disease 
Management of Asthma" seminar. 
Come and join a distinguished faculty 
as they review the NIH asthma 

guidelines, marketing the asthma 
program, pharmacology, and 
numerous other aspects of asthma 
program management. 
Contact: The AARC Conventions 
Office at (972) 243-2272. 

October 1 — Melville, New York 
The NYSSRC's Southeastern Chapter 
hosts their 3 1 st annual symposium, 
"Respiratory Care — A Work in 
Progress," at the Huntington Hilton 
Hotel in Melville, Long Island. The 
keynote address will be given by Carl 
Wiezalis, vice-president of the AARC. 
Contact: For information, call Jim 

October 20-22— Daniels, West 


The West Virginia Society for 
Respiratory Care will host its Annual 
Fall Meeting at the Glade Springs 
Resort, Country Inns and Suites. 
Contact: For more information, 
contact Jay Wildt, co-chair of 
program and education, at 
(304) 442-7474. 

December 13-16 — Las Vegas, Nevada 
The AARC's 45th International 
Respiratory Congress is scheduled for 
Dec. 13-16 (Monday through 
Thursday) at the Las Vegas 
Convention Center. Sessions 
appealing to all levels of health care 
providers will be offered, with CRCE 
credit available. Exhibits by 
international manufacturers of 
cardiopulmonary equipment will be 
featured. Additional information will 
be available in the fall. 

Other Meetings 

August 19-20 — Cleveland, Ohio 
The Cleveland Clinic Foundation is 
sponsoring a continuing education 
program titled "Respiratory Therapy," 
which has been approved for Category 
1 accreditation. It will be held at the 
Omni International Hotel. 

Contact: For more information, call 
Laurie Martel at (216) 444-5696 or 

September 16-19 — Phoenix. Arizona 
The American Association of 
Cardiovascular and Pulmonary 
Rehabilitation will hold its 14th 
annual meeting at the Phoenix Civic 

Contact: For more information, call 
(608) 831-6989;; 

October 1-3 — Ottawa, Ontario, 


The Canadian COPD Alliance will 
host "Building and Enriching 
Partnerships in the Management of 
COPD" at the Radisson Hotel Ottawa 
Centre. This conference will include 
plenary sessions on the epidemiology 
of COPD and scientific workshops on 
spirometry, smoking cessation, and the 
evidence to support management 
approaches to COPD. Included is a 
series of practical workshops on 
rehabilitation and a parallel consumer 
track for those who live with COPD. 
Contact: call (613) 747-6776 or see 
their web site at 

October 4-5 — Ann Arbor, Michigan 
The Office of Continuing Medical 
Education at the University of 
Michigan is sponsoring a conference, 
"Update on FVImonary and Critical 
Care Medicine," at the Towsley Center. 
Contact: For more information, 
contact Laura Castellanos at 
(734) 647-8784. 

October 31-November 4 — Chicago, 


The American College of Chest 
Physicians will host their 65th Annual 
International Scientific Assembly at 
the Lakeside Center. For information, 
contact Member Services at (800) 
343-2227, fax (847) 498-5460, or 

Respiratory Care • July 1999 Vol 44 No 7 



Notices of competitions, scholarships, fellowships, examination dates, new educational programs. 

and the like will be listed here free of charge. Items for the Notices section must reach the Journal 60 days 

before the desired month of publication (January I for the March issue, February 1 for the April issue, etc). Include all 

pertinent information and mail notices to RESPIRATORY CARE Notices Dept, 1 1030 Abies Lane. Dallas TX 75229-4593. 


^ Helpful Lileb.Sites 

American Association for Respiratory Care 

— Current job listings 

— American Respiratory Care Foundation 
fellowships, grants, & awards 

— Clinical Practice Guidelines 

National Board for Respiratory Care 


— 1 997 Subject and Author Indexes 

— Contact the editorial staff 

Asthma Management 
Model System 

The National Board for Respiratory Care — 1999 Examination Dates and Fees 


Examination Date 

Examination Fee 

CRTT (CRT) Examination 

November 13, 1999 

$120 (new applicant) 

Application Deadline: September 1, 1999 

80 (reapplicant) 

RRT Examination 

December 4, 1999 

120 written only (new applicant) 

Application Deadline: August 1 , 1 999 

80 written only (reapplicant) 
130 CSE only (all applicants) 
250 Both (new applicants) 
210 Both (reapplicants) 

For information about other services or fees, write to the National Board for Respiratory Care, 
8310 Nieman Road, Lenexa KS 66214, or call (913) 599-4200, FAX (913) 54 l-0156,or e-mail: 










Asthma Disease Management Course Comes to 

"Disease Management of Asthma," a newly designed day- 
and-a-haif course, will be held in Cleveland Sept 24-25. 
Drawing on the expertise of a nationally recognized fac- 
ulty, this course has been developed in accordance with 
the National Institute of Health Asthma Guidelines for 
the Diagnosis and Management of Asthma. Completing 
this course will earn respiratory therapists 11 hours of 
continuing education credit. Topics covered include dis- 
ease management, pharmacology, educational strate- 
gies, marketing your program, outcomes management, 
and age-specific issues. Register on-line or call the AARC 
for registration materials. The program will be held 
September 24-25, at the Marriott Cleveland Airport 
Hotel. Registration before August 30, 1999 is $175 for 
AARC members, $250 for non-members. (After August 
30, register for $275 member, $350 non-member) 

AARC Exhibition Becomes 'Selling Showr' 

The AARC's 45th International Respiratory Congress 
will, for the first time in its history, provide attendees 
and exhibitors the opportunity to negotiate sales of prod- 
ucts and equipment at the exhibitor show, December 13 
-16, in Las Vegas. More than 200 equipment manufac- 
turers, pharmaceutical companies, service organiza- 
tions, and supply companies will exhibit at the show. 
"We've always had an extremely enthusiastic response to 
our exhibiting companies," said AARC Executive Direc- 
tor Sam Giordano. "We decided to take that approach 
this year to make attending the meeting even more cost 
effective — and the show specials and discounts our 
exhibitors are providing will make the exhibition an even 
greater success," he said. 

New Products Help with Clinical Practice 

These products from the AARC, some newly introduced, 
will help in both clinical practice situations and in 
administration, in acute care and post-acute care. Check 
them out: 

Diagnostic Training and Competence Assessment Man- 
ual for Pulmonary and Noninvasive Cardiology. CDRom. 
$267 for AARC members. This manual (on compact disk) 
is ideal for use in course development, training, orienta- 
tion, and competence assessment for individuals in the 
laboratory setting. A pulmonary diagnostics section 
features quality control, diffusing capacity, whole body 
plethysmography, arterial blood gas sampling, 
bronchoscopy and seven other procedures. The noninva- 
sive cardiology section features EEC, stress testing, event 
monitoring, exercise testing and three other procedures. 

Asthma Disease State Management. Video and 
workbook. $79.95 for members. Provides instruction in 
how to create an effective asthma disease management 
program in your facility. Covers diagnosis, pharmacolog- 
ical therapy, environmental controls, patient/family edu- 
cation, and case studies. Approved for two hours of CRCE 
credit and nursing CE credit. 

Orientation and Competency Assurance Documentation 
Manual. Manual. $65 for members. Provides the informa- 
tion, assessment tools, and models necessary to 
demonstrate that the competence of employees is 
documented according to JCAHO requirements. 

Uniform Reporting Manual for Acute Care. Manual. $65 
for members. Provides you with nationally recognized 
standards for documenting workload units and time 
standards. Includes patient assessment activities and cov- 
ers bronchial hygiene, supplemental oxygen, airway care, 
diagnostic tests, and cardiovascular diagnostics. 

Uniform Reporting Manual for Subacute Care. Manual. 
$75 for members. Provides tools to determine productiv- 
ity, track trends in the utilization of respiratory care ser- 
vices, assist in determining personnel requirements, 
measure demand for and intensity of services, and meet 
the requirements of prospective payment systems (PPS). 

Respiratory Home Care Procedure Manual. Manual. $80 
for members. The new "Respiratory Home Care 
Procedure Manual" is specifically designed for the home 
care setting. And, it is easily adaptable to any alternate 
care site from subacute to home medical equipment 
companies and nursing agencies. The manual features 
five sections of information, forms, and checklists for the 
patient and practitioner. 



in This Issue 

Au, David 869 

Beckett, Ronald G 867 

Bishop, Michael J 750 

Campbell, Robert S 799 

Heffner, John E 807, 861 

Hess, Dean R 759 

Kapur, Vishesh 866 

Orringer, Maxine K 845 

Reibel, James F 820, 856 

Sassoon, Catherine 866 

Stauffer, John L 828 

Watson, Charles B 777 

in This Issue 

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Fax (972) 484-6010. Rick Owen is the Marketing Director for RESPIRATORY CARE. 

Blake Medical, Inc 

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Disclaimer. The opinions expressed in any article or editorial are those 
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for the consequences of the clinical applications or use of any methods or de- 
vices described in any article or advertisement. 

Subscription rates. Individual subscription rates are $75 per year 
(12 issues), $145 for 2 years, and $215 for 3 years in the US and Puerto 
Rico. Rates are $90 per year, $ 1 75 for 2 years, and $260 for 3 years in all other 
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made payable to RESPIRATORY CARE and sent to the subscription office at 
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SUBSCRIPTION Rates for associations. Basic annual subscrip- 
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Change of Address. Notify the AARC at (972) 243-2272 as soon as pos- 
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Copyright © 1999, by Daedalus Enterprises Inc. 





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17 33 

in This Issue 

Au, David 

Beckett, Ronald G . . 
Bishop, Michael J . . 
Campbell, Robert S . 
Heffner, John E . . . , 
Hess, Dean R 

.... 869 Kapur, Vishesh 866 

.... 867 Orringer, Maxine K 845 

.... 750 Reibel, James F 820, 856 

.... 799 Sassoon, Catherine 866 

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759 Watson, Charles B 777 

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The new view of Ventilation 

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GALILEO IS available from your local HAMILTON MEDICAL partner. For further information, contact HAMILTON MEDICAL at, phone +41-81-641-2627, fax +41-81-641-2689 or call our local representative. 

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For all. 


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The proven choice for secretion clearance and reversal of atelectasis. ' 

Today, more patients than ever can benefit from TheraPEP, 
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offers significant time savings for both patients ani clinicians. 

1 Mcllwaine, RM., Wong, L.T., Peacock, D., Davidson, G.F. "Long-term 
comparative trial of conventional postural drainage and percussion versus 
positive expiratory pressure physiotherapy in the treatment of cystic fibrosis." 
Ihe \ourm\ of Pediatrics, October 1997. 

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Respiratoi v Care. AARC Times, May 1997. 

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Innovations for respiratory care 

3 Mahlmeister MJ, Fink JB, Hoffman GL, Fifer LF, "Positive-expiratory-pressure 
mask therapy: Theoretical and Practical Considerations and a Review of the 
Literature", Rfspirafory Care, 1991; 36:1218-1230. 

4 "AARC Clinical Practice Guideline: 'Use of Positive Airway Pressure Adjuncts 
to Bronchial Hygiene Therapy'," Resp/rafory Care, 1993; 38:516-521. 

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