Vasculotoxic Snake Bite -

SVMPs degrade the basement membrane of capillary endothelial cells. By cleaving type IV collagen, laminin, and fibronectin, they increase vascular permeability, leading to local edema, blistering, and systemic capillary leak syndrome. This directly causes petechiae, ecchymosis, and spontaneous systemic hemorrhage.

PLA2 enzymes damage endothelial cell membranes directly and promote the release of inflammatory mediators (leukotrienes, prostaglandins). They also inhibit platelet aggregation through the hydrolysis of platelet membrane phospholipids, exacerbating the bleeding diathesis. vasculotoxic snake bite

Unlike physiological thrombin, venom serine proteases (e.g., ancrod, batroxobin) cleave fibrinogen to fibrin without activating factor XIII. This produces unstable, loose fibrin clots that are rapidly lysed, leading to defibrination syndrome . Concurrently, venom activates factor X and prothrombin, leading to consumptive coagulopathy. SVMPs degrade the basement membrane of capillary endothelial

Vasculotoxic snake bites, primarily from the Viperidae family (e.g., Russell's viper , Saw-scaled viper , Pit vipers ), constitute a major medical emergency in tropical and subtropical regions. Unlike neurotoxic envenomation, vasculotoxicity targets the vascular endothelium and coagulation cascade, leading to hemorrhage, thrombosis, and consumptive coagulopathy. Objective: To review the pathophysiology, clinical manifestations, diagnostic challenges, and evidence-based management of vasculotoxic snake envenomation. Key Findings: The venom contains metalloproteinases (SVMPs), serine proteases, and phospholipase A2 enzymes that disrupt endothelial integrity, activate coagulation factors inappropriately, and induce platelet aggregation followed by depletion. Clinically, patients present with progressive local swelling, hemorrhagic blebs, systemic bleeding (gingival, intracranial), and acute kidney injury (AKI). The 20-minute whole blood clotting test (20WBCT) remains a crucial bedside diagnostic. Antivenom is the mainstay of treatment, though its efficacy is species-specific. Adjunctive management includes aggressive hydration, monitoring for compartment syndrome, and renal replacement therapy. Conclusion: Vasculotoxic envenomation carries high morbidity and mortality due to hemorrhage and renal failure. Early administration of species-specific polyvalent antivenom, along with close monitoring of coagulation parameters, remains the cornerstone of management. PLA2 enzymes damage endothelial cell membranes directly and

Pathophysiology, Clinical Spectrum, and Management of Vasculotoxic Snake Envenomation: A Comprehensive Review

The term "vasculotoxic" is somewhat of a misnomer, as the venom primarily affects blood vessels and blood components. Key families include Viperidae (e.g., Daboia russelii , Echis carinatus , Bothrops atrox ) and some Colubridae. In India, Southeast Asia, Sub-Saharan Africa, and Latin America, viper bites account for the majority of vasculotoxic envenomations. The clinical syndrome is dominated by local tissue destruction, coagulopathy, and systemic vascular leakage. Without prompt intervention, patients succumb to intracranial hemorrhage, acute kidney injury (AKI), or hypovolemic shock. The vasculotoxic action is mediated by a complex mixture of enzymes and peptides.

[Generated for Academic Purposes] Affiliation: Department of Internal Medicine & Tropical Medicine