Treatment of blast injuries of the extremity.

Blast trauma is a complex event. Pathophysiologically, blast injuries are identified as primary (caused solely by the direct effect of blast overpressure on the tissue), secondary (caused by flying objects or fragments), tertiary (caused by bodily displacement), or quaternary (indirectly caused by the explosion). The range of primary blast injuries includes fractures, amputations, crush injury, burns, cuts, lacerations, acute occlusion of an artery, air embolism-induced injury, compartment syndrome, and others. Secondary injuries are the most common extremity blast injuries. Like primary injuries, they may necessitate limb amputation, be life-threatening, and produce severe contamination. Tertiary blast injuries of the extremity may result in traumatic amputations, fractures, and severe soft-tissue injuries. Quaternary injuries most often are burns. Following treatment and stabilization of immediate life-threatening conditions, all patients are given antibiotic and tetanus prophylaxis. Débridement and wound excision are started as early as possible, with repeat débridement performed as necessary; fasciotomies also are performed to prevent compartment syndrome. Well-vascularized muscular free flaps provide soft-tissue coverage for blast-injured extremities. The closed-open technique of flap closure allows reexamination of the wound, further irrigation, débridement, and later bone and soft-tissue reconstruction.