Snake envenomation and acute kidney injury: a systematic review and meta-analysis

Abstract

BACKGROUND: Snakebite envenomation remains a health problem in tropical regions and is a recognized cause of acute kidney injury (AKI). Despite numerous regional studies, the global burden and predictors of snakebite-induced AKI have not been systematically quantified. This review aimed to estimate the pooled incidence of AKI following snake envenomation, identify key clinical and laboratory features, and determine the mortality rate and proportion of patients requiring renal replacement therapy (RRT). METHODS: A systematic search of PubMed, Embase, and Cochrane Library was conducted for studies published between 2015 and 2025 that reported AKI in snakebite patients. Eligible studies included observational and interventional designs with ≥ 10 participants. Data were extracted on study characteristics, incidence of AKI, need for RRT, mortality rate and associated clinical and laboratory features. Quality was assessed using the Joanna Briggs Institute checklist. Pooled incidence estimates were generated using a DerSimonian–Laird random-effects model, and heterogeneity was evaluated using the I² statistic. RESULTS: Thirty studies comprising 8,612 participants met the inclusion criteria. The pooled incidence of AKI following snake envenomation was 23% (95% CI: 17–33%; I² = 97.2%), and among these, 28% (95% CI: 17–43%; I² = 86.9%) required RRT and the pooled mortality rate was 10% (95% CI 4–21%), with substantial heterogeneity (I² = 83%). A high incidence was observed among Russell’s viper victims, 37% (95% CI: 21–57%), and 23% (95% CI: 15–34%) in non-Russell’s viper victims. Common clinical predictors of AKI included older age, male sex, comorbidities (hypertension, diabetes mellitus), local swelling, cellulitis, bleeding, hypotension, oliguria/anuria, and delayed presentation. Laboratory features included incoagulable 20-min whole blood clotting test (WBCT), prolonged prothrombin time/ international normalized ratio (PT/INR), elevated serum creatinine and blood urea and nitrogen (BUN), thrombocytopenia, and proteinuria. Biomarkers such as urinary neutrophil gelatinase–associated lipocalin (NGAL), cystatin C, and β-2 microglobulin were associated with early renal injury. CONCLUSION: Approximately one-third of snakebite victims develop AKI, and nearly one in three affected patients requires dialysis. Clinical manifestations such as coagulopathy and local tissue injury are commonly observed. Early recognition, prompt antivenom therapy, and supportive renal management are critical to improving outcomes. CLINICAL TRIAL: Not applicable.