Chapter 1 deals with the important question of when to intubate. If airway obstruction is severe, progressive, or potentially imminent, then immediate action (often cricothyrotomy) is required without further consideration of moving the patient to another venue (e.g., the operating room or another hospital). Failing such an indication for an immediate cricothyrotomy, the question becomes more difficult: What is the expected clinical course?

Penetrating wounds to the neck and airway are notoriously unpredictable (see Chapter 31). Some experts advocate securing the airway regardless of warning signs, whereas others advocate
expectant observation. There are substantial problems with the second strategy. The first is that the patient often remains relatively asymptomatic until they suddenly and unexpectedly develop total obstruction, resulting in an airway (and patient) that cannot be rescued. The second is that unless a flexible endoscope is used, the observer is only able to see the anterior portion of the airway and not the posterior and inferior parts where the obstruction likely will occur. In other words, when not using a flexible endoscope, one sees only “the tip of the iceberg.”

The time course of the airway threat also is important. All other things being equal, a patient who presents with substantial airway swelling, such as angioedema, which has developed over 8 to 12 hours, is likely at substantially less risk for sudden obstruction than a similar patient where the same degree of swelling has developed over 30 minutes. Overall, for any condition in which the obstruction may be rapidly progressive, silent, and unobservable externally (e.g., angioedema, vascular injuries in the neck, and epiglottitis), acting earlier to secure the airway rather than later is the most prudent course.

There are four cardinal signs of acute upper airway obstruction:

The first two signs do not necessarily suggest that total upper airway obstruction is imminent; however, stridor and dyspnea do. The patient presenting with stridor has already lost at least 50% of the airway caliber and requires immediate intervention. In the case of children younger than 8 to 10 years with croup, medical therapy may suffice. In older children and adults, the presence of stridor typically mandates a surgical airway or, at the least, intubation using a double setup. This technique uses an awake attempt from above, ideally using a flexible endoscope, with the capability, prepared in advance, to rapidly move to a surgical airway if needed. Properly performed bag mask ventilation often will be successful in cases with soft tissue obstructions, including laryngospasm, but generally will not overcome a fixed obstruction, such as extrinsic compression of the airway by a hematoma, and, in any case cannot be counted on as more than a temporizing maneuver.

The key considerations here are as follows: