Early pathology in venom-induced consumption coagulopathy by Rhabdophis tigrinus (Yamakagashi snake) envenomation

Objective:Rhabdophis tigrinus (Yamakagashi in Japanese) is a venomous non-front-fanged colubroid snake capable of inflicting envenoming with life-threatening defibrinating coagulopathy. However, because of the uncommon incidence of bites and tendency for late development of symptoms/signs, the early effects of the venom on the coagulation system are poorly known. Case report: We describe a boy bitten by a wild R. tigrinus and report his clinical course starting at 30 min after the bite. Results: At 30 min after envenomation, only the thrombin-antithrombin complex (TAT) level was elevated. At 90 min after envenomation, laboratory data revealed a prolonged activated partial thromboplastin time (APTT) and increased prothrombin time international normalized ratio (PT-INR) with elevated fibrinogen degeneration product (FDP). At 5.5 h after envenomation, APTT and PT-INR increased beyond a measurable range, and fibrinogen levels dropped below the detection limit. We administered recombinant human soluble thrombomodulin and antivenom prepared against R. tigrinus antivenom. Venom-induced consumption coagulopathy (VICC), which is sometimes reported as disseminated intravascular coagulation (DIC), subsequently improved rapidly. Discussion: We found that TAT is the earliest marker to detect R. tigrinus envenomation and subsequent VICC occurrence. Although rTM was effective in this case, further studies are necessary to prove its safety and efficacy.