Failure of antivenom to improve recovery in Australian snakebite coagulopathy

Abstract

Background: Venom-induced consumption coagulopathy (VICC) is an important feature of snake envenoming. Aim: To investigate the effect of antivenom and fresh frozen plasma (FFP) on recovery of VICC in Australian elapid snake envenoming. Design: Prospective cohort study. Methods: Patients with VICC were included from the Australian Snakebite Project (ASP). Time to recovery of VICC (defined as time until INR <2) was investigated using a time to event analysis in WinBUGS. The model considered the effects of age, sex, snake type, time of antivenom after bite, antivenom dose and use of FFP within 4 h. Results: The study included 167 cases of VICC, median age being 41 [interquartile range (IQR): 28-53) years, and 130 (78%) were males. Antivenom was administered at a median of 3.6 (IQR: 2.2-5.6) h after the bite at a median dose of four vials (IQR: 2-6 vials). Thirteen patients received FFP within 4 h. Recovery of VICC occurred after a median of 14.4 (IQR: 11.5-17.5) h, and only the use of FFP within 4 h influenced the time to recovery. Neither antivenom dose nor time of antivenom administration had an effect on recovery of VICC. In patients administered with FFP, 12% [credible interval (CrI): 6-21%] and 81% (CrI: 61-94%) had recovered at 6 and 12 h, respectively, vs 2.5% (CrI: 1.5-4%) and 28% (CrI: 22-34%) not receiving FFP. Discussion: Antivenom did not appear to be effective for the coagulopathy in snake envenoming in Australia. FFP appeared to shorten the time of VICC recovery. © The Author 2009. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved.