Snake-Bite Envenomation and Early Kidney Risk: Duration to Hospital, Coagulation Indices and Species as Predictors of Acute Kidney Injury in Southern India – A Prospective Observational Study

Abstract

Background Snake-bite is a neglected medical emergency in the tropics. Acute kidney injury (AKI) is its gravest systemic complication and is potentially preventable if patients at risk are recognised early. Simple, rapidly available indices—time-to-hospital, 20-min whole-blood-clotting-time (WBCT20), pro-thrombin time/international normalised ratio (PT-INR) and offending species—may offer reliable bedside predictors but have not been examined in a single analytic framework.

Methods We prospectively studied 100 consecutive adults (> 15 y) with proven or strongly suspected envenomation admitted to Gulbarga Institute of Medical Sciences (June 2023–Dec 2024). Demography, bite-to-hospital interval, species (clinical identification or dead specimen), WBCT20, PT-INR (at admission and 24 h) and serum creatinine were recorded. AKI was defined by KDIGO criteria. Indices independently associated with AKI were explored with multivariable logistic regression.

Results Median age was 55 y (IQR 38–68) and 53 % were male. Median bite-to-hospital interval was 11 h (IQR 7–16). Krait (29 %), Russell’s viper (26 %) and cobra (21 %) accounted for 76 % of bites. AKI developed in 24 patients (24 %) at a mean of 0.7 ± 1.4 days. Russell’s viper accounted for 54 % of AKI (adjusted OR 5.4, 95 % CI 2.0–14.7, p = 0.002). A bite-to-hospital interval > 12 h was present in 67 % of AKI versus 32 % of non-AKI patients (aOR 3.1, 1.2–7.8, p = 0.018). All AKI cases showed incoagulable WBCT20 and prolonged PT-INR at baseline; PT > 15 s or INR > 1.2 at 24 h remained independently associated with AKI (aOR 4.6, 1.3–16.0). Model-AUROC was 0.87. Dialysis was required in 6/24 (25 %) AKI cases and overall mortality was 8 %, confined to the AKI cohort.

Conclusion (1) Delay > 12 h, (2) Russell’s viper bite, (3) incoagulable WBCT20 and (4) persistent PT-INR derangement at 24 h reliably identify victims at very high risk of AKI. These bedside variables should prompt pre-emptive renal-protective strategies and early transfer to dialysis-capable centres in resource-limited settings.