Intraoperative failure of a Fluotec Mark II vapourizer

A case report describing the failure of a Fluotec Mark II vapourizer to deliver the indicated anaesthetic concentration during surgery is presented. The failure was caused by a broken internal circlip which resulted in most of the fresh gas flow bypassing the vapourizer. The inspired halothane concentration was reduced to 0.1 per cent, irrespective of the vapourizer dial setting. This type of vapourizer failure may be identified by the unusually loose dial on the Mark II vapourizer. The complications resulting from a light level of anaesthesia include awareness, systolic and diastolic hypertension, movement, and their sequelae.