The difficult airway in adults
- Ron M Walls, MD, FRCPC, FAAEM
Ron M Walls, MD, FRCPC, FAAEM
- Editor-in-Chief — Adult and Pediatric Emergency Medicine
- Section Editor — Adult Resuscitation
- Professor of Medicine
- Harvard Medical School
- Brigham and Women's Hospital
- Michael F Murphy, MD, FRCPC
Michael F Murphy, MD, FRCPC
- Professor and Chair of Anesthesia and Pain Medicine
- University of Alberta
Most emergency department (ED) endotracheal intubations are performed on an emergent basis (ie, intubation cannot be delayed or avoided). The universal emergency airway management algorithm© provides the recommended approach to emergency intubation (algorithm 1 and algorithm 2) [1,2]. This approach is based on two key assessments of the patient prior to intubation.
The first assessment is to determine if the patient has a "crash" airway (ie, presenting in extremis with little or no cardiovascular or respiratory activity, and unlikely to respond to insertion of a laryngoscope). If so, the crash airway algorithm© is used (algorithm 3) .
If the patient is not a crash airway, the next step is to determine if the patient presents a difficult airway. This requires assessment of specific patient attributes to predict the likelihood of difficulty in performing any of the major procedures in airway management: direct laryngoscopy and intubation, bag-mask ventilation, surgical airway management, and ventilation using an extraglottic airway.
If the patient is felt to be neither a crash nor a difficult airway, then rapid sequence intubation is the recommended method for managing the airway. (See "Rapid sequence intubation in adults".)
The decision that the patient presents with a difficult airway is a critical determinant of the best approach to intubation. This topic review will discuss assessment and management of the difficult airway in adults. Other aspects of airway management, including pediatric airway management, are discussed separately. (See "The difficult pediatric airway" and "Emergent endotracheal intubation in children" and "Basic airway management in adults" and "Advanced emergency airway management in adults" and "Rapid sequence intubation in adults".)
- Walls RM. The emergency airway algorithms. In: Manual of Emergency Airway Management, 4th, Walls RM, Murphy MF. (Eds), Lippincott Williams and Wilkins, Philadelphia 2012. p.24.
- The airway management algorithms cited in this review are reproduced with permission from: The Difficult Airway Course™: Emergency, and Walls RM, Murphy MF. Manual of Emergency Airway Management, Lippincott Williams & Wilkins, Philadelphia 2008, and 4th ed, 2012.
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- The mnemonics for difficult airway identification cited in this review are reproduced with permission from The Difficult Airway Course™: Emergency.
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- Incidence of difficult intubation
- Incidence of difficult bag-mask ventilation
- Incidence of difficult cricothyrotomy
- Incidence of difficult extraglottic airways
- IDENTIFICATION OF THE DIFFICULT AIRWAY
- The LEMON© approach to difficult airway assessment
- - L: Look externally
- - E: Evaluate (3-3-2 rule)
- - M: Mallampati score
- - O: Obstruction/Obesity
- - N: Neck mobility
- Difficult bag-mask ventilation
- Difficult cricothyrotomy
- Difficult extraglottic airway placement
- THE DIFFICULT AIRWAY ALGORITHM©
- Applying the algorithm
- - Is the operator forced to act?
- - Is there time?
- - Is RSI reasonable?
- - Awake technique
- - Alternatives
- Failed airway
- SUMMARY AND RECOMMENDATIONS