Effect of Australian elapid venoms on blood coagulation: Australian Snakebite Project (ASP-17)

Snake venoms contain toxins that activate the coagulation network and cause venom-induced consumption coagulopathy. A previously developed mathematical model of the coagulation network was refined and used to describe and predict the time course of changes in the coagulation factors following envenomation by Brown snake (Pseudonaja spp.), Tiger snake (Notechis scutatus), Rough-scaled snake (Tropidechis carinatus) and Hoplocephalus spp. (Stephens banded, Pale headed and Broad headed). Simulations of the time course of the change in coagulation factors were compared to data obtained from a large prospective study of Australian snake bites - the Australian Snakebite Project. The model predictions were also compared against data for partial and complete VICC obtained from the same study. The model simulations were used to understand the differences in consumption and recovery of clotting factors in partial versus complete VICC as well as among bites from different snake types. The model suggested that the venoms were absorbed almost instantaneously and provided a reasonable prediction of the observed concentration of clotting factors over time in patients bitten by Australian elapid snakes. The model predictions suggested a higher consumption of factors (fibrinogen, II and IX in particular) in patients with complete VICC compared to those with partial VICC. The model also predicted that snakes with "Xa-like" venoms may produce a less severe VICC than snakes with "Xa:Va-like" venoms.