Mention the term ‘difficult airway’ and many of us will conjure mental images of some kind of distorted anatomy. However, airway management may be ‘difficult’ for a number of reasons, and no internationally agreed definition of the term exists. Given the wrong staff and circumstances, an ‘easy’ airway in your or my hands may indeed become very difficult. In their editorial “The myth of the difficult airway: airway management revisited” (1) Huitink & Bouwman state:
“In our opinion, the ‘difficult airway’ does not exist. It is a complex situational interplay of patient, practitioner, equipment, expertise and circumstances.”
Airways that are anatomically difficult (eg. limited mouth opening, short thyromental distance, large tongue, neck immobility, etc.) and physiologically difficult (hypoxaemia, hypotension, acidosis) are well described among FOAM resources (2-4). In addition to these, a third category of difficulty is well worth considering.
At the smaccDUB conference, intensivist and human factors legend Peter Brindley described three types of difficult airway:
- Anatomically difficult
- Physiologically difficult
- Situationally difficult
This last category probably surfaces more commonly than realised, particularly outside the operating room.
Imagine attending a cardiac arrest call on a medical ward. The patient is a 70 year old 120 kg male. The nurses have flattened the bed and discarded the pillow to optimise supine position for CPR. Gobs of vomitus splash from the patient’s pharynx with each compression. The wall suction system is disconnected. There is no bougie in the crash cart’s airway drawer. The nearest capnograph is on another floor of the hospital. In this scenario, no matter how excellent the critical care practitioner’s airway skills, this is a damned difficult airway.
I think Brindley’s third category is a term that should catch on, as a way of helping analyse cases that progress suboptimally and to identify factors during pre-intubation checks that can be addressed. It is terminology that I have added to my own Resuscitese Lexicon, particularly for case discussions during morbidity & mortality and airway audit meetings.
I would like to hear the ‘Situationally Difficult Airway‘ become more widely used, as it fills a gap in how we describe this important area of resuscitation practice.
1. Huitink JM, Bouwman RA. The myth of the difficult airway: airway management revisited. Anaesthesia. 2015 Mar;70(3):244–9. (Full text)