Prognostic significance of clinical grading of patients envenomed by Bothrops lanceolatus in Martinique

Abstract

The correlation between clinical grading of patients bitten by Bothrops lanceolatus and the subsequent development of their envenoming was examined. Severity of envenoming was graded using a 1–4 scale (minor to major). Patients were classified into 2 groups according to the time elapsed between bite and treatment with a specific purified equine F(ab′)2 antivenom. The late/no treatment group ( n = 33) was characterized by a systemic thrombotic complication rate of 14 33 (42·4%) leading to 4 deaths, which increased with the maximum severity assessed on the first day following the bite ( P = 0·003). However, infarctions could develop in patients who presented initially with signs of moderate envenoming, normal blood clotting and low serum levels of venom antigens. No such complication or fatality occurred in the early (0·5–6 h) treatment group ( n = 70). Multiple regression analysis showed that duration of stay in hospital in this group increased with the length of the snake ( P = 0·017), venom antigenaemia ( P = 0·016), initial grading ( P < 0·001), and with the need for surgical debridement ( n = 10 70 , P < 0·001 ). Outcome was correlated with initial severity of envenoming. However, the only factor with a positive prognostic significance for the individual envenomed patient was the early infusion of specific antivenom, which led to 100% recovery in our series.