Severe Red-Necked Keel-Back Snake (Rhabdophis subminiatus) Envenomation in Two Cases and a Literature Review.

In the present article, two cases of envenomation by Rhabdophis subminiatus are reported, including a detailed analysis of the toxicological mechanisms, clinical manifestations, and therapeutic management, along with a systematic review of globally reported cases of Rhabdophis subminiatus envenomation. Both patients (both male, aged 58 years and 55 years, respectively) sought medical treatment several days after being bitten on the hand and developed life-threatening consumptive coagulopathy and hemorrhagic diathesis. The 58-year-old patient (Case 1) presented with local swelling, pain, abdominal hematoma, and shortness of breath. After treatment with antivenom, transfusion of packed red blood cells, fresh-frozen plasma, cryoprecipitate, and mechanical ventilation, his coagulation function returned to nearly normal levels. He was discharged 15 days after admission to the study hospital. The 55-year-old patient (Case 2) presented with oral bleeding and swelling distal to the bite site. After treatment with antivenom and transfusion of fibrinogen concentrate, packed red blood cells, and fresh-frozen plasma, his coagulation function returned to normal. He was discharged 11 days after admission to the study hospital. A literature review revealed more than 50 reported cases worldwide, all of which highlighted hemorrhagic syndrome and profound coagulopathy as hallmark features. Most cases were managed symptomatically, with only a minority receiving antivenom. Although the overall prognosis was generally favorable, the case fatality rate reached 12.7%. Envenomation by Rhabdophis subminiatus constitutes a significant medical emergency that requires early intervention with polyvalent antivenom (such as anti-Agkistrodon/Deinagkistrodon antivenom) combined with targeted supportive therapy to optimize clinical outcomes.