Factor assay in victims of snake bite: Experience from a tertiary care institute in South India

Snake bites tend to cause a high mortality in those who develop coagulopathy. However, there is very limited literature on clotting factor assays in these patients, especially in the presence of clinical bleeding. The aim was to assess the coagulation profile and individual coagulation factors in patients with hematotoxic snake bites.

This was a prospective observational study of clotting factor levels in victims of snake bites with hematotoxicity admitted to a single hospital in south India for 12 months. In 43 individuals who fulfilled the criteria, we measured platelet count, prothrombin time (PT), international normalized ratio, activated partial thromboplastin time (aPTT), fibrinogen levels, coagulation factors V, VII, VIII, IX, and X, and the qualitative factor XIII assay.

Forty-three patients fulfilled the criteria and their samples were studied. There were 36 Russell's viper (Daboia russelli), 4 Hump-nosed pit viper (Hypnale hypnale), and 3 unknown snake bite victims samples, in which factor assays were done. All the Russell viper bite victims without a recordable clotting screen had deficiency of Factor V (0.5%-49.62%, Mean - 20.27%), Factor X (0.08%-92.3%, Mean - 70.73%), and qualitative factor XIII. Pit viper patients showed normal levels of Factor I, V, VII, VIII, IX, X, and XIII despite prolonged PT and aPTT.

Early detection and treatment of envenomation remains the cornerstone of managing snake venom-induced consumptive coagulopathy. Anti-snake venom plays a major role in the reversal of coagulopathy. Blood and blood products would be useful when coagulopathy does not revert by ASV alone. Evidence-based transfusion can be implemented and cryoprecipitate may be used as many of the patients had factor XIII and fibrinogen deficiency as part of venom-induced coagulopathy. To improve patient management and thereby the outcome of patients CMEs and training programs for the treating physicians also has to be implemented so that guidelines are formulated and followed.