A Case of Suspected Negative Pressure Pulmonary Edema after General Anesthesia.

Negative pressure pulmonary edema (NPPE) can occur rapidly after the release of an upper airway obstruction. In general anesthesia, NPPE can be caused by laryngospasm after extubation. This report describes a case in which NPPE was thought to have occurred after extubation during general anesthesia in a disabled person. The patient was a 28-yearold man, 160 cm in height and 56 kg in weight, who was scheduled for dental caries treatment under ambulatory general anesthesia due to intellectual disability. After induction of general anesthesia, nasal intubation was performed after sufficient oral suctioning to remove a large amount of serous secretion. After completion of dental treatment, pressurized extubation was performed after oral suctioning as sufficient spontaneous breathing and body movement were observed. Immediately after extubation, SpO ₂ dropped to 80%, subsequently recovering to 99% under oxygen administration at 5 liter/min with an oxygen mask. It dropped to approximately 85% again, however, when administration of oxygen was discontinued. Although communication with the patient was difficult, no expression of anguish or dyspnea was observed. A chest radiograph showed symmetric middle-lobe and lingular segment infiltrates, and the patient was transferred to the nearest general hospital. No obvious clinical findings other than a decrease in SpO ₂ were observed, suggesting NPPE as a result of airway narrowing due to secretions.