Pilot studies of pressure-immobilization bandages for rattlesnake envenomations.
OBJECTIVE
Pressure-immobilization bandages sequester venom in extremities and are recommended for snakebites without local toxicity. Pilot studies were performed to determine the time of onset of toxicity and efficacy of pressure-immobilizations bandages in a porcine model of rattlesnake envenomation.


METHODS
After IACUC approval, anesthetized pigs were injected subcutaneously in a distal hind leg with 200 mg of Crotalus atrox venom. After 1 min, pigs received either a pressure-immobilization bandage (N = 3) or no treatment (N = 3). At 24 h, surviving pigs received antivenin and then the pressure-immobilization bandages were removed. Surviving subjects were followed for 1 week. Chi-square analysis and paired t-test were used.


RESULTS
Pigs with pressure-immobilization bandages survived for 24 h, whereas untreated pigs died at 13.68 +/- 3.42 h (p = 0.014). Surviving pigs walked on the extremity at 7 days. Potassium rose from 4.033 +/- 0.252 at baseline to 17.767 +/- 5.218 mEq/L (p < 0.0001) at time of death in untreated pigs but was normal at 24 h in treated subjects. Widespread tissue necrosis was seen in the untreated group but only local necrosis in the treatment group.


CONCLUSIONS
Pressure-immobilization bandages prevented death from severe C. atrox envenomations with a 24 h delay to treatment. Surviving pigs had recovery of limb use at 1 week.
Meggs
William Joel
WJ
Department of Emergency Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA. meggsw@ecu.edu
Courtney
Christine
C
O'Rourke
Dorcas
D
Brewer
Kori Louise
KL
D000818:Animals; D000997:Antivenins / Q000627:therapeutic use; D003435:Crotalid Venoms / Q000008:administration & dosage / Q000633:toxicity*; D017839:Crotalus; D003627:Data Interpretation, Statistical; D006470:Hemorrhage / Q000139:chemically induced / Q000473:pathology; D018482:Muscle, Skeletal / Q000473:pathology; D009336:Necrosis; D009779:Occlusive Dressings / Q000009:adverse effects; D010865:Pilot Projects; D012909:Snake Bites / Q000473:pathology / Q000628:therapy*; D016019:Survival Analysis; D013552:Swine
D000997:Antivenins; D003435:Crotalid Venoms