Disseminated intravascular coagulation caused by the carpet viper (Echis carinatus): trial of heparin.

Heparin has been advocated for the treatment of poisoning by Echis carinatus, a snake whose venom causes disseminated intravascular coagulation. Fourteen patients with proven E. carinatus bite who had incoagulable blood were treated with specific Echis antivenom. Seven of them were also given low-dose heparin, initially 50 units/kg body weight by i.v. injection, followed by 10 units/kg/h by i.v. infusion for 22 h. Response to treatment was assessed clinically and by repeated tests of blood coagulation. All patients showed a rapid return to normal blood coagulability after treatment and the heparinized group were not significantly different in any respect from the group given antivenom alone. Heparin did not reduce the local effects of envenoming. There appears to be no place for heparin in the treatment of E. carinatus poisoning provided that potent antivenom is available. The in vivo results were supported by in vitro studies in which it was found that Echis-induced thrombin was less sensitive to the inhibitory effect of heparin than physiological thrombin.