An Internist's Approach to a Case of Negative Pressure Pulmonary Edema: A Rare Cause of Noncardiogenic Pulmonary Edema.

Negative-pressure pulmonary edema (NPPE) is a rare cause of noncardiogenic pulmonary edema, which usually presents postoperatively. Its pathophysiology is mostly described as a profound negative intrathoracic pressure caused by an airway obstruction such as laryngospasm, which may occur during extubation. But, there are other hypotheses about it, such as catecholamines release causing an elevated hydrostatic pressure in the cardiopulmonary circuit and, consequently, a major capillary leak to the interstitium. Its natural course varies, from prompt recovery to intensive care unit escalation and prolonged mechanical ventilation. Although anesthesiologists often detect this condition, this case's objective is to bring awareness of this condition to internists as a potential differential diagnosis for hypoxia in the postoperative setting.