"Airway management" may be defined as the application of therapeutic interventions that are intended to affect gas exchange in patients. Gas exchange is the fundamental feature of this definition.1 A number of devices and techniques are commonly employed in health-care settings to achieve this goal, for example, bag-mask-ventilation (BMV), extraglottic devices (EGDs), oral or nasal endotracheal intubation, and surgical airway management techniques.
The failure to adequately manage the airway has been identified as a major factor leading to poor outcomes in anesthesia, critical care, emergency medicine, and emergency medical services (EMS).2,3 In fact, adverse respiratory events constituted the largest single cause of injury in the ASA Closed Claims Project.4 Furthermore, it has been repeatedly shown that the single most important factor leading to a failed airway is the failure to predict the difficult airway.3-5
Screening tests designed to predict difficult laryngoscopic intubation in otherwise normal patients have proven to be so unreliable that airway practitioners need to be prepared to manage a failed airway every time they are faced with a patient in need of airway management.6,7
This chapter deals with the identification of the difficult and failed airway, particularly in an emergency, in which evaluation and management must be done concurrently in a compressed time frame and canceling the case or delaying management is not an option.
Successful airway management is generally governed by four intertwined factors:
- A clinical situation of varying urgency, venue, and resources
- Patient factors including airway anatomy and vital organ system reserve
- Available airway resources
- Skills of the airway practitioner
Because one must choose a method of airway management from an array of techniques, some degree of precision of language is essential. For example, a difficult oral laryngoscopy and intubation may not necessarily constitute a difficult airway if BMV is easily performed. Furthermore, a difficult laryngoscopic intubation does not mean a difficult intubation using a lightwand or using a video laryngoscope. In the same way, a failed intubation does not necessarily constitute a failed airway. A failed intubation, defined narrowly as the failure to intubate the trachea on three attempts,6,8 may not constitute a failed airway if one is able to affect gas exchange with BMV or with an EGD. However, intubation failure ought to conjure a sense of urgency and mandates the airway practitioner to rapidly switch to a failed airway management sequence because such a situation may become life-threatening if gas exchange cannot be provided expeditiously and adequately by other means. Furthermore, the alternative airway technique employed must have the highest degree of success in the practitioner's skill set. It is inappropriate to make random disorganized attempts to manage the airway in the hope that one of the airway techniques might work. Rather, one should have a planned strategy (See the Algorithms in Chapter 2) including invasive techniques such ...