Warming blanket head drapes and trapped anesthetic gases: understanding the fire risk

Polyethylene warming blanket head drapes are widely used to help surgical patients maintain normothermia. The OR quality management team at Froedtert Hospital, Milwaukee, Wisconsin, designed a quality improvement project using an intubation mannequin to determine whether a head drape used on an intubated patient would enhance the risk of ignition in the presence of an undetected anesthesia system gas leak. The team revealed several significant factors, including higher oxygen flow rate, the presence and application of the head drape, and not using the warming blanket blower, in the accumulation of oxidizers. Considerations for the surgical team when using the head drape include cutting a fenestration in the drape around the endotracheal tube or otherwise venting the drape, using the blanket blower, and having the anesthesia care provider frequently lift the head drape, thus minimizing the accumulation of trapped gases.