Difficult Airway

Excerpt

A difficult airway is a clinical situation in which a healthcare provider who is skilled at airway management encounters difficulty with one or more standard methods of airway management. The definition is not standardized in the literature and there are some variations between national expert guidelines. The American Society of Anesthesiologists defines a difficult airway as existing when "a conventionally trained anesthesiologist experiences difficulty with facemask ventilation of the upper airway, difficulty with tracheal intubation, or both." Canadian guidelines are broader, defining it as where "an experienced provider anticipates or encounters difficulty with any or all of face mask ventilation, direct or indirect (e.g., video) laryngoscopy, tracheal intubation, SGD [supraglottic device] use, or surgical airway." Another potential factor is the expected status of the airway at the time of extubation.

The difficulty of airway management is highly variable and will depend on several factors including patient characteristics, medical and surgical history, airway examination, the clinical context for which airway management is required (including the nature of any planned surgical procedure), and the patient's current status and vital signs. Appropriate training, experience, risk assessment, and clinical judgment are seen as essential to reliably predict the difficulty of managing a particular patient's airway. Where an airway is judged to be basic or straightforward, it is expected that a healthcare professional who is well-trained in airway management would normally be able to proceed without complications. More advanced airways lack these reassuring factors and are potentially complex; they may require infrequently-used techniques and access to a team with special skills or devices. However, real-world airway assessment is often highly subjective and even specialist clinicians will have significant difficulty in accurately predicting which cases will be challenging. Some studies suggest that more than 90% of difficult airways are unanticipated.

Algorithms for managing the difficult airway have been outlined by national and international bodies such as the American Society of Anesthesiology and the Difficult Airway Society. These provide a basic pathway for difficult intubation. It is vital that all clinicians who attempt intubation be familiar with the equipment and techniques necessary for successful intubation. In the Closed Claims Analysis performed by the American Society of Anesthesiology, failed intubation remains a major cause of morbidity and mortality.