title: Awareness under anaesthesia due to a defective gas-loaded regulator.
abstract: Awareness under anaesthesia occurred in two patients due to a defect in an anaesthesic machine, which caused an inadequate supply of nitrous oxide. A defective fail-safe gas-loaded regulator was found to have caused communication between the pipelines for oxygen and nitrous oxide. This resulted in oxygen flow through the nitrous oxide flowmeter. A simple test to detect this type of defect is suggested.
mesh_terms: D000769:Anesthesia, Inhalation / Q000295:instrumentation*; D001364:Awareness; D003071:Cognition; D004868:Equipment Failure; D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology; D008297:Male; D010146:Pain