Negative-Pressure Pulmonary Hemorrhage: A Case Report and Review of Differential Diagnosis.

Negative-pressure pulmonary hemorrhage (NPPH) represents an uncommon complication of acute upper airway obstruction. During emergence from anesthesia, strenuous inspiratory efforts can generate profound negative intrathoracic pressure. This mechanism not only drives alveolar fluid extravasation, leading to negative-pressure pulmonary edema, but can also precipitate capillary stress failure and subsequent alveolar hemorrhage. We present the case of a healthy young patient who developed NPPH following partial strangulation without obvious tube occlusion or laryngospasm. This report discusses the diagnostic challenges, differential considerations, and the supportive management that led to a rapid resolution of symptoms.