A season of snakebite envenomation: presentation patterns, timing of care, anti-venom use, and case fatality rates from a hospital of southcentral Nepal

Snakebite envenomation affects thousands of people annually in Nepal. Published hospital-based studies of snakebite treatment in Nepal are scarce. Here we present the results of the first prospective, cross-sectional study of hospitalized envenomed snakebite cases in southcentral Nepal, a region characterized by poor pre-hospital care of snakebites, limited supply and excessive use of antivenom, and a high case/fatality ratio. We seek to identify clinical management problems and suggest potential interventions to improve treatment of snakebites. Out of the 342 patients presented with snakebites to an urban emergency department in the Terai region of Nepal between April and September of 2007, 39 patients were enrolled based on development of ptosis or swelling of bitten body parts. We collected patient demographic information and documented circumstances of snakebite, prehospital care, hospital care, and development of complications. Among 39 envenomated patients admitted to Bharatpur Hospital enrolled in the study 34 (92%) exhibited features of clinically significant neurotoxicity and were treated with antivenom. Antivenom use ranged from 4 to 98 vials of Polyspecific Indian Antivenom per patient. Each of victims (n=34) received antivenom an average of 4.3 (median) ±0.73 (standard error of mean) hours after receiving the snakebite. The overall case fatality rate was 21%. Neurotoxicity developed up to 25.8hr after suspected elapid snakebites. This was not observed for viperid snake bites. No enrolled patients received any of the currently recommended first aid for snake bite. The prevalence of nocturnal elapid snake bites, the practice of inappropriate first aid measures and highly variable administration of antivenom were identified as major challenges to appropriate care in this study. To address these issues we suggest development of a comprehensive checklist for identification of snake species, management of envenomation, and an educational program which teaches proper care at all stages of snakebite treatment.