The difficult airway is a topic both ubiquitous and vaguely defined in clinical anesthesia practice. The most common characterization is a clinical situation in which a conventionally trained anesthesia provider has difficulty mask ventilating, intubating, or both. How one approaches difficult airway management varies based on provider preference, experience, and patient considerations. What guidelines exist are broad and open to interpretation, but there are common threads that should at minimum be considered.
Recognition of the difficult airway is necessary for adequate preparation. Risk factors in a patient’s history (e.g. previous difficult mask/intubation, obstructive sleep apnea, head and neck radiation, mediastinal mass, ankylosing spondylitis) and physical exam (table below) should be reviewed whenever possible prior to induction.
Patient education of possible airway difficulties and their consequences, considering having a second pair of hands, prioritizing adequate preoxygenation, and actively pursuing ways to continue delivering supplemental oxygen for the duration of airway management (e.g. via nasal cannula, LMA, insufflation) are part of the basic preparation recommended by the ASA. How the anesthesiologist chooses to secure the airway is dependent on provider familiarity and patient considerations, and includes video laryngoscopy, fiberoptic intubation, and light wand.
One of the most important considerations is whether to perform airway management before or after induction. Awake intubation with fiberoptic scope or glidescope with adequate topical anesthetic is the safer and more defensible alternative to asleep airway instrumentation in cases of recognized difficult airway in which it is very likely that a cannot ventilate/cannot intubate situation may occur.
The unanticipated difficult airway will be encountered by anesthesia providers despite careful preoperative assessment. Like ACLS, the difficult airway algorithm (shown below) should be periodically reviewed and referred to in systematically attempting to establish adequate ventilation and/or intubation.
References:
Apfelbaum, JL et al. 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 02 2013, Vol.118, 251-270.