Transcript Airway Management: New Information, Old Problems

Topics in Airway Management:
Intelligent Airway Evaluation
Donald M. Voltz, MD
Assistant Professor of Anesthesiology
Case Western Reserve University / University Hospitals of Cleveland
3 November 2004
What we focus on and our
mental models determine what
we see.
What is Intelligence?
Intelligence = Behavior
Turing Test
Intelligence = Prediction
Is There Such a Thing as an
Unexpected Difficult Intubation?
What is the Problem?
“More than 85% of respiratoryrelated closed claims involve a
brain-damaged or dead patient.”
Jonathan Benumof, MD
Incidence of Difficult Intubation
• Successful with
multiple attempts
• Successful, many
attempts, many
people
• Unsuccessful
• Can not ventilate or
intubate
• 100-1800/10,000
(1-18%)
• 100-400/10,000
(1-4%)
• 5-35/10,000
(0.05-.35%)
• 0.01-2/10,000
(0.0001-0.02%)
What do we want to Predict?
Cormack-Lehane Classifications
Airway Prediction Models
Airway Prediction Models
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Mallenpatti Classification
Neck Range of Motion
Thyromental/Thyrosternal Distance
Upper Lip Bite Test
Multivariate Analysis
Mallinpatti Classification
Mallinpatti Classification
Upper Lip Bite Test
Upper Lip Bite Test
Table 1. Relationship Between the Results of Two Predicting Tests and Laryngoscopy
Grades in 300 Patients
Laryngoscopic view
Predicting test
I and II
III and IV
Modified Mallampati
Classes I and II
Classes III and IV
189
3
94
14
251
4
32
13
Upper lip bite
Classes I and II
Class III
ASA Difficult Airway
Algorithm
Updated 2003
Airway Evaluation
Mouth (4)
Oral Cavity (3)
Neck (4)
Airway Evaluation - Mouth
• Length of Upper Incisors
• Relationship of Maxillary Incisors to
Mandibular Incisors
• Ability to Prognath the Mandible
• Interincisor Distance
Airway Evaluation – Oral Cavity
• Visibility of the Uvula
• Shape of the Palate
• Compliance of the Mandibular Space
Airway Evaluation - Neck
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Thyromental/Thyrosternal Distance
Length of the Neck
Thickness of the Neck
Range of Motion of the Head and Neck
Approaching the Difficult
Airway Algorithm
William H. Rosenblatt, M.D.
Yale University School of
Medicine
Is Airway Management
Required?
Do you predict difficult direct
laryngoscopy?
Will superlarngeal ventilation
be possible?
Predictors of Difficult Mask
Ventilation
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Age greater than 55 years
Body mass index greater than 26 kg/m2
History of snoring
Edentulous
Presence of facial hair
Is the patient at an increased
risk of aspiration?
Will the patient tolerate a
judgment error?
Problems with Prediction Methods
Future of Airway Prediction
References
• Rosenblatt, W.H. Decision making in airway
evaluation. ASA Refresher Course in
Anesthesiology, V. 32, 2004.
• Benumof, J.L. Airway Management, pp. 121158, 1996.
• ASA Task Force on Airway Management.
Practice Guidelines for Management of the
Difficult Airway: An Updated Report by the
American Society of Anesthesiologists Task
Force on Management of the Difficult Airway,
Anesthesiology, 98(5), 1269-1277.