Clotting factor replacement and recovery from snake venom-induced consumptive coagulopathy

Abstract

Using clotting factors (fresh frozen plasma and/or cryoprecipitate) to treat snake venom-induced consumptive coagulopathy (VICC) is controversial. We aimed to determine if factor replacement after antivenom is associated with an earlier return of coagulation function. We retrospectively analysed VICC cases due to brown snake (genus Pseudonaja), tiger snake (Notechis, Tropidechis, and Hoplocephalus), and taipan (Oxyuranus) envenoming. Recovery of international normalized ratio (INR)/prothrombin time (PT) was compared between patients who did not receive factor replacement and those who did, and between patients who received factor replacement <or= 4 h of commencing antivenom and those who received factor replacement later or not at all. There was no significant difference between cases receiving clotting factors and cases that did not, however in 21 cases having factor replacement within 4 h, the median time to coagulation recovery was 4.6 h (interquartile range [IQR] 3.5-8.8), versus 9.5 h (IQR 7.3-13) in 106 cases who had clotting factors later or not at all (P < 0.001). No serious adverse effects attributed to clotting factors were recorded. Recovery by 6 h after starting antivenom was also more likely in those who were younger, in tiger snake envenoming, and where the interval between bite and starting antivenom was longer. The initial dose of antivenom did not appear to influence the likelihood of recovery at 6 h. Early factor replacement after antivenom is associated with earlier improvement of coagulation function. Randomised controlled clinical trials to determine the efficacy and safety of factor replacement for VICC after venom neutralisation are required.