This postoperative patient with tachycardia, tachypnea, and persistent hypoxemia following initiation of supplemental oxygen is in acute respiratory failure; she requires urgent stabilization, which is best accomplished with endotracheal rapid-sequence intubation (RSI). RSI makes use of a rapidly acting sedative (eg, etomidate, propofol, midazolam) and a paralytic agent (eg, succinylcholine, rocuronium) to facilitate emergent intubation while preventing aspiration. Once intubated and stabilized, the cause of this patient's acute respiratory failure can be diagnosed and managed.