Negative pressure pulmonary edema: report of three cases and review of the literature.

Pulmonary edema following the relief of an upper airway obstruction is an uncommon and unpredictable clinical entity. This unusual disease is actually attributed to pulmonary and hemodynamic changes engendered by high negative intrathoracic pressures during the state of obstructed respiration, such as laryngospasm, epiglottitis, laryngotracheal neoplasm, etc. In this article, we report three cases of negative pressure pulmonary edema (NPPE) developed after the operations of tracheotomy, adenoidectomy, and microlaryngeal surgery. The etiology, pathophysiology, diagnosis, management, and outcome of NPPE are also brought into further discussion.