WITHDRAWN: Successful use of haemato-polyvalent anti-venom cross-neutralisation in the clinical management of Rhabdophis subminiatus (Rhabdophis keelback) envenomation

As the landscape becomes more urbanized, snakebites have increasingly become uncommon presentations to the emergency departments in Singapore, while snakebites causing significant envenomation are even rarer. In this case report, we discuss a 55-year-old man who had significant envenomation from a Rhabdophis keelback (Rhabdophis subminiatus) and who was successfully treated with haemato-toxic polyvalent antivenom (HPAV). He initially presented with pain, swelling and bleeding over his wound. Due to a deterioration in his coagulation profile, he was given two doses of HPAV which is typically reserved for viperid snakes instead. Following administration of the anti-venom, the patient’s coagulation profile improved and the local soft tissue effects of the venom resolved. He did not manifest any adverse effects and was discharged uneventfully about 72 hours after the snakebite. The cross-neutralization potential of HPAV for Rhabdophis Colubrid venom in this case study suggests that there may be a possible common underlying chemical structure and pathophysiology among the venom proteins of various snake species. Given that Rhabdophis-specific antivenom is unavailable in most countries, this cross-neutralization strategy deserves further consideration and evaluation in similar circumstances. The patient was successfully treated using HPAV with resolution of envenomation and discharged uneventfully. The possible cross neutralization potential of HPAV for Rhabdophis (colubrid) venom in our case may suggest a possible common underlying structure and pathophysiology of venom proteins amongst different snake species.