The Difficult Airway Redefined.

There is no all-encompassing or universally accepted definition of the difficult airway, and it has traditionally been approached as a problem chiefly rooted in anesthesiology. However, with airway obstruction reported as the second leading cause of mortality on the battlefield and first-pass success (FPS) rates for out-of-hospital endotracheal intubation (ETI) as low as 46.4%, the need to better understand the difficult airway in the context of the prehospital setting is clear. In this review, we seek to redefine the concept of the "difficult airway" so that future research can target solutions better tailored for prehospital, and more specifically, combat casualty care. Contrasting the most common definitions, which narrow the scope of practice to physicians and a handful of interventions, we propose that the difficult airway is simply one that cannot be quickly obtained. This implies that it is a situation arrived at through a multitude of factors, namely the Patient, Operator, Setting, and Technology (POST), but also more importantly, the interplay between these elements. Using this amended definition and approach to the difficult to manage airway, we outline a target-specific approach to new research questions rooted in this system-based approach to better address the difficult airway in the prehospital and combat casualty care settings.