Bag valve mask failure during HEMS intubated stretcher winch.

An intubated prehospital trauma patient was undergoing bag valve mask (BVM) ventilation during a stretcher winch in an AW 139 helicopter. On approach to approximately 50 feet under the rotor disc, the bag valve mask failed, with no adverse outcome. External pressure obstructing reinflation from rotor downwash was thought to be the cause. We tested two BVMs with differing compliances under similar conditions in a manikin model and found the original, more compliant BVM failed again. The stiffer, less compliant BVM did not fail. This has led to a change in the type of BVM used for helicopter emergency medical services (HEMS) in our service. Copyright Â