Airway management is the most important skill for an emergency practitioner to master because failure to secure an adequate airway can quickly lead to death or disability. Endotracheal intubation using rapid sequence intubation (RSI) is the cornerstone of emergency airway management.
The decision to intubate is sometimes difficult; clinical experience is required to recognize signs of impending respiratory failure. Patients who require intubation have at least one of the following 5 indications: 1) inability to maintain airway patency, 2) inability to protect the airway against aspiration, 3) ventilatory compromise, 4) failure to adequately oxygenate pulmonary capillary blood, 5) anticipation of a deteriorating course that will eventually lead to the inability to maintain airway patency or protection.
RSI is the preferred method of endotracheal intubation in the emergency department (ED) because it results in rapid unconsciousness (induction) and neuromuscular blockade (paralysis). This is important in patients who have not fasted and are at much greater risk for vomiting and aspiration. To this end, the goal of RSI is to intubate the trachea without having to use bag-valve-mask (BVM) ventilation, which is often necessary when attempting to achieve intubating conditions with sedative agents alone (eg, midazolam, diazepam). Instead of titrating to effect, RSI involves administration of weight-based doses of an induction agent (eg, etomidate) immediately followed by a paralytic agent (eg, succinylcholine, rocuronium) to render the patient unconscious and paralyzed within 1 minute. This method has been proven safe and effective in EDs over the past 2 decades, and it is considered the standard of care.
The class is determined by looking at the oral cavity as the patient protrudes the tongue, and tongue size is described relative to oropharyngeal size. The test is conducted with the patient in the tongue wide open and relaxed and protruding to the maximum. The subsequent classification is based on the pharyngeal structures that are visible.
Scoring is as follows:
Class 1: Full visibility of tonsils, uvula, and soft palate.
Class 2: Visibility of hard and soft palate, upper portion of tonsils, and uvula.
Class 3: Soft and hard palate and base of the uvula are visible.
Class 4: Only hard palate visible.