Low dose of snake antivenom is as effective as high dose in patients with severe neurotoxic snake envenoming

The objective of this study was to evaluate the effects of two different dosage protocols on the outcome of patients with severe neurotoxic snake envenoming, using a retrospective analysis of patients admitted with a diagnosis of severe neurotoxic snake bite over a 4 year period. In the study, 55 snake bite victims requiring ventilatory support for severe neurotoxic envenoming received either 150 ml of polyvalent snake antivenom (SAV) ( low dose SAV group, n = 28) or 100 ml of SAV at presentation followed by 100 ml every 6 hours until recovery of neurological manifestations ( high dose group, n = 27). The median dose of SAV in the high dose group was 600 ml ( range 300 to 1600). The duration of mechanical ventilation in the low dose group ( median 47.5 hours; range 14 to 248) was similar to that in the high dose group ( median 44 hours; range 6 to 400). The mean (SD) duration of intensive care unit stay was similar in the two groups. There were three deaths in the high dose group; two patients in the low dose group had neurological sequelae. All other patients improved, had no residual neurological deficit, and were discharged. We conclude that there is no difference between a protocol using lower doses of SAV and one with higher doses in the management of patients with severe neurotoxic snake envenoming.