Negative-pressure pulmonary edema (NPPE) is a clinical entity of anaesthesiologic relevance, perioperatively caused by obstruction of the conductive airways (upper airway obstruction, UAO) due to laryngospasm in approx. 50% of the cases, its early recognition and treatment by the anaesthesist is mandatory. NPPE, also addressed as post-obstructive pulmonary edema (POPE) presents in most cases as a complex of symptoms with rapid onset, consisting of acute respiratory failure with dyspnea, tachypnea, and strained respiratory efforts. Additional signs are paradoxe ventilation, pink frothy sputum, stridor, and severe agitation. UAO produce extreme reduction of intrathoracic pressure during spontaneous ventilation, consecutively causing increase in venous return to the right ventricle and in intrathoracic blood volume, resulting in elevated hydrostatic pressures and interstitial transudation of fluids. Partially due to largely differing criteria used for diagnosis, opinions about incidence and prevalence of NPPE are unhomogenous in medical literature. It has been shown that generation of NPPE is not only limited to patients being intubated and ventilated, but occurs also in patients requiring higher fractions of oxygen.