Surgical considerations in the management of pit viper snake envenomation.

Envenomation by North American pit viper snakes (family Viperidae, subfamily Crotalinae, genera Crotalus [rattlesnakes], Sistrurus [pygmy rattlesnakes], and Agkistrodon [copperhead and cottonmouth snakes]) is a dynamic and potentially serious medical condition. Each year in the United States, approximately 9,000 patients are treated for pit viper snakebite and 5 die. Pit viper venoms are complex mixtures with up to 50 different active components, including enzymes, nonenzymatic polypeptides, glycoproteins, and nonprotein components. Metalloproteinases, phospholipases A2, and inflammatory mediator analogues produce tissue injury; activate complement; damage vascular endothelium; degrade fibrinogen; activate platelets; and cause systemic effects, including hemodynamically important fluid shifts, bleeding, and neurotoxicity. The overall management of pit viper victims has been reviewed recently. General care includes parenteral analgesia, antivenom administration, and serial assessments of limb swelling and laboratory tests. Despite the presence of soft tissue inflammation, prophylactic antibiotics are rarely required, and most patients achieve good outcomes with supportive care and antivenom alone. The case-fatality rate in rattlesnake envenomation is very low, approximately 1 per 700 patients about whom a poison center was consulted. Death due to copperhead snake envenomation is extremely rare, with only 1 fatal case reported to US poison centers during a 5-year period.