Note: for management see: Difficult Airway Management

• Resuscitative airway management in the emergency department (ED) in the adult population (>16 years of age) is a relatively rare but complex and challenging scenario that includes overdose, trauma, sepsis, airway obstruction, respiratory failure amongst others.
• By definition, the difficult airway includes difficulty with:
  • Bag mask ventilation (BMV; oxygenation and ventilation);
  • Supraglottic device ventilation/oxygenation; and/or
  • Laryngoscopy and intubation
• It is reasonable to assume that every ED airway intervention is difficult until proven otherwise and to be generally prepared for a difficult airway challenge.
• It is possible to predict a difficult airway and to risk stratify patients undergoing procedural sedation who may need airway management during the sedation intervention.
• However, no difficult airway prediction tool is robust and all have suboptimal test characteristics; be prepared!

The Difficult Airway in the ED may be inferred by asking three questions:

1. Is the patient potentially difficult to BMV?

• Predicts whether pre-oxygenation or rescue oxygenation will be easy or difficult.
• Any positive component of “BOOTS” (“bearded, older, obese, toothless and/or snoring”) independently predicts potential difficulty with BMV.

2. Is the patient potentially difficult to intubate?

• “MMAP”: Mallampati class, Measurement (“3-3-1 rule”), Atlanto-occipital extension, Pathology

Mallampati classification (Class 1 to IV), with mouth opening and extruding tongue in a cooperative patient without phonation is a predictor of difficulty of intubation (Roughly Class 1 = “easy” and Class IV = “difficult). Atlanto-occipital extension: In the absence of Cspine precautions, the patient’s ability to flex the neck at the cervico-thoracic junction and extend the head at the atlanto-axial junction is a predictor of intubation. Pathology means pathologic processes at the periglottic inlet/area including both medical pathology (angioedema, infection, tumors etc) or trauma pathology (blunt or penetrating) and predicts potential considerable difficulty with intubation.

• (Other mnemonics exist such as “LEMON”: Look externally, Evaluate 3-3-2 rule, Mallampati score, Obstruction, Neck Mobility).

3. Is the patient potentially difficult to “rescue” with a supraglottic device or difficult to perform a surgical airway on?

The associated mnemonic for difficult “rescue” question (with supraglottic device) is:  RODS: Restricted mouth opening, Obstruction, Distorted airway, Stiff lungs or c-spine.

The associated mnemonic for predicting a difficult surgical airway = SHORT: Surgery, Hematoma, Obesity, Radiation distortion or other deformity, Tumor.

1. The above image of Difficult Airway Algorithm is used with permission. Source:
   Henderson JJ, Popat MT, Latto IP, Pearce AC. Difficult Airway Society guidelines for management of the unanticipated difficult intubation. Anaesthesia 2004; 59: 675-94, with permission from Blackwell Publishing Ltd.

   
   

2. AIME Airway Interventions and Management in Emergencies – Accessed July 25, 2017.

   
   

3. Difficult Airway Society Guidelines – Accessed July 25, 2017.

   
   

4. Airway Management in Emergencies – Open-access online textbook from www.aimeairway.ca.

   
   

1. Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults. C. Frerk, V. S. Mitchell, A. F. McNarry, C. Mendonca, R. Bhagrath, A. Patel, E. P. O’Sullivan, N. M. Woodall and I. Ahmad, Difficult Airway Society intubation guidelines working group British Journal of Anaesthesia, 115 (6): 827–848 (2015) doi:10.1093/bja/aev371.

   
   

2. Walls RM, Murphy MF, eds: Manual of Emergency Airway Management, 4th ed. Philadelphia: Lippincott, Williams & Wilkins; 2012.

   
   

3. Rosen’s emergency medicine: concepts and clinical practice / Editor-in-Chief Ron M. Walls; Senior Editors Robert S. Hockberger, Marianne Gausche-Hill; Editors Katherine Bakes, Jill Marjorie Baren, Timothy B. Erickson, Andy S. Jagoda, Amy H. Kaji, Michael VanRooyen, Richard D. Zane.

   Ninth edition. Copyright © 2018 by Elsevier, Inc.

   Chapter 1: Airway

   Calvin A. Brown and Ron M. Walls

   
   

4. Airway Management in Emergencies, Aug 1 2011, George Kovacs, J. Adam Law, et al. Chapter 12. Approach to an Encountered Difficult Airway, pp 253-298, McGraw-Hill Europe; 2 edition.

   
   

5. Crosby ET, Cooper RM, Douglas, et al. The unanticipated difficult airway with recommendations for management. Can J Anaesth. 1998 Aug;45(8):757-76.