S R Offerman1, T S Smith, R W Derlet. 1. Division of Emergency Medicine, Department of Internal Medicine, University of California-Davis Medical Center, 2315 Stockton Blvd, PSSB 2100, Sacramento, CA 95817, USA. rxsteeps@aol.com
Abstract
OBJECTIVE: To determine the incidence and severity of acute side effects from the use of polyvalent antivenin in victims of rattlesnake bites. DESIGN: We retrospectively reviewed the records of all patients who presented with rattlesnake bites to a university teaching hospital during an 11-year period. From patient medical records, we extracted demographic data, clinical measurements, and outcomes during emergency department evaluation and subsequent hospitalization. Data regarding serum sickness were not collected. OUTCOME MEASURES: Primary outcome variables were the occurrence of immediate hypersensitivity reaction to antivenin, the type of reaction, permanent disability at hospital discharge, and mortality. RESULTS: We identified a total of 73 patients with rattlesnake bites during the study period. Bite envenomation was graded as nonenvenomated, 7 patients (10%); mild, 23 patients (32%); moderate, 32 patients (44%); and severe, 11 patients (15%). We identified 65 patients who received antivenin. Antivenin doses ranged from 1 to 30 vials per patient (mean, 12.0 +/- 6.0), for a total of 777 vials. In 43 patients (66%), 10 or more vials of antivenin were given. The mean number of vials of antivenin given to each snakebite grade were as follows: mild, 8.4 (+/-4.0); moderate, 11.8 (+/-5.7); and severe, 18.7 (+/-6.3). No deaths, amputations, or permanent disability from snakebite occurred in the patients receiving antivenin. Acute side effects of antivenin-occurring within the first 6 hours after administration-were seen in 12 patients (18%; 95% confidence interval, 10%-30%). Acute side effects consisted solely of urticaria in all but 1 patient (2%; 95% confidence interval, 0%-8%). This patient had a history of previous antivenin reaction and required a short course of intravenous epinephrine for blood pressure support. No other complications occurred. CONCLUSION: The administration of polyvalent Crotalidae antivenin is safe. Acute hypersensitivity, when it occurs, consists solely in most cases of urticaria. Serious side effects are uncommon.
OBJECTIVE: To determine the incidence and severity of acute side effects from the use of polyvalent antivenin in victims of rattlesnake bites. DESIGN: We retrospectively reviewed the records of all patients who presented with rattlesnake bites to a university teaching hospital during an 11-year period. From patient medical records, we extracted demographic data, clinical measurements, and outcomes during emergency department evaluation and subsequent hospitalization. Data regarding serum sickness were not collected. OUTCOME MEASURES: Primary outcome variables were the occurrence of immediate hypersensitivity reaction to antivenin, the type of reaction, permanent disability at hospital discharge, and mortality. RESULTS: We identified a total of 73 patients with rattlesnake bites during the study period. Bite envenomation was graded as nonenvenomated, 7 patients (10%); mild, 23 patients (32%); moderate, 32 patients (44%); and severe, 11 patients (15%). We identified 65 patients who received antivenin. Antivenin doses ranged from 1 to 30 vials per patient (mean, 12.0 +/- 6.0), for a total of 777 vials. In 43 patients (66%), 10 or more vials of antivenin were given. The mean number of vials of antivenin given to each snakebite grade were as follows: mild, 8.4 (+/-4.0); moderate, 11.8 (+/-5.7); and severe, 18.7 (+/-6.3). No deaths, amputations, or permanent disability from snakebite occurred in the patients receiving antivenin. Acute side effects of antivenin-occurring within the first 6 hours after administration-were seen in 12 patients (18%; 95% confidence interval, 10%-30%). Acute side effects consisted solely of urticaria in all but 1 patient (2%; 95% confidence interval, 0%-8%). This patient had a history of previous antivenin reaction and required a short course of intravenous epinephrine for blood pressure support. No other complications occurred. CONCLUSION: The administration of polyvalent Crotalidae antivenin is safe. Acute hypersensitivity, when it occurs, consists solely in most cases of urticaria. Serious side effects are uncommon.