Clinical predictors of tissue necrosis following rattlesnake envenomation

AbstractBackground: Rattlesnake envenomation (RSE) causes edema, hemotoxicity and tissue necrosis. Necrosis may result in permanent disability.Objective: To study patient-related factors associated with tissue necrosis after Crotalus envenomation.Methods: Prospective cohort study of patients admitted to the Medical Toxicology service with diagnosis of RSE between April 2011 and November 2014. Inclusion criteria were age ≥18 years and upper extremity (UE) envenomation site. Primary outcome was tissue necrosis, including dermonecrosis, manifesting as bullae. Secondary outcome was amputation.Results: 77 subjects, age 18 to 88 years, met inclusion criteria. Rattlesnake species was unknown in most cases. All received Fab antivenom. 62 (82%) had a digital envenomation. 31 (40.3%) had necrosis. Necrotic area ranged from 0.1 cm2 to 14 cm2. Procedural interventions, (superficial debridement, dermotomy, surgical exploration, and operative debridement of devitalized tissue) occurred in 25 (32.5%). Five (6.5%) underw...