Full-thickness burn to the hand from an automobile airbag

An 18-year-old male was involved in a single car motor vehicle accident in which the driver's side airbag was deployed. He presented to the trauma center with complex injuries to the left hand, lacerations to the scalp, and a full-thickness burn to the ulnar aspect of the right hand that included the hypothenar area and the fifth digit. The patient was admitted to the trauma center and received immediate consultation from the burn service. He underwent debridement and split-thickness skin grafting of 50 cm2 of the right hand on postburn day 3. The graft became necrotic and the patient underwent debridement of the skin and the abductor minimi muscle of the right hand on postburn day 32. Split-thickness skin grafting and release of flexion contracture were successfully completed 18 days later. The police and fire departments reported that the airbag showed signs of thermal destruction. Upon request, Honda motors submitted information from the TRW safety systems and material safety data sheet (Mesa, Ariz, issued 1989) that showed that airbag canisters contain the chemicals sodium azide and cupric oxide. Water may react with sodium azide to form highly toxic and explosive hyfrazoic acid. These chemicals are converted to sodium hydroxide, which can cause significant chemical burns. In addition, these chemicals may ignite when exposed to live electrical wires or temperatures greater than 300 degrees F. We conclude that burns associated with damaged deployed airbags in motor vehicle accidents may be the results of both chemical and thermal injury. The extent of the burn wound may be underestimated, as our case illustrates. Full-thickness burns resulting from airbag deployment may require more aggressive initial debridement and treatment.