Venomous snakebite - An outcome based analysis in a tertiary care hospital.

Background: Snake bite is the prime of all neglected tropical diseases wherein our health care systems have little success. The spectrum of manifestations range from minimal edema to full blown Multi Organ Dysfunction Syndrome[MODS] and death. The presentation varies according to the geographic location and the regional predominance of various species. Though there are voluminous data on the subject, few researchers have focused on the extrinsic factors leading to adverse outcome after a venomous bite. This study aimed to elucidate the modifiable extrinsic factors which are associated with adverse outcomes after a venomous bite. Materials and Methods: A retrospective study was conducted based on the electronic data base and case sheets of snakebite envenomed patients at Government Villupuram Medical College and Hospital. 200 cases of snakebite envenomation were included in the study. Only systemically envenomed adult patients were enrolled. The case records and electronic data base were systematically analysed and the modifiable extrinsic factors associated with adverse outcomes documented. The primary adverse outcomes were acute kidney injury requiring hemodialysis, respiratory failure with prolonged ventilator support, Multi Organ Dysfunction Syndrome[MODS], compartment syndrome and death. For each adverse outcome the associations were noted under 2 separate heads- Clinical findings and management issues. The data were compared with patients who had favorable outcome. The data were compared using a two-sided Wilcoxon rank sum test and the unpaired student's t-test. „P‟ value <0.05 was considered as significant. Results: A total of 200 patients were included in the study. The male to female ratio was 1.9:1. 77%[154] of cases suffered hemotoxic envenomation , 19% neurotoxic and 4% was a mixture of both. The principle adverse outcome frequency was AKI 22(11%), respiratory failure with prolonged ventilator support 13(6.5%), MODS 8(4%), compartment syndrome 5(2.5%) and death 7(3.5%). AKI was significantly associated with hemotoxic envenomation(90.9%), dehydration(36.3%), shock(36.3%), hematuria(54.5%), delayed presentation[>6 hrs](40.9%) and high dosage of ASV [>20 vials]. Respiratory failure had significant relation with late presentation(76.9%), krait bite(61.5%) and aspiration pneumonitis(38.4%). The management issues showed that (92.3%) weaning protocol was not followed. MODS had a cause and effect correlation with hemotoxic envenomation100% and high dose ASV(87.5%). Finally the ultimate adverse outcome of death was associated with hemotoxic envenomation (85.7%), delayed presentation(71.4%), MODS (100%) and high dose ASV(75%). Conclusion: In our study we identified a few modifiable factors which are a significant cause for dismal outcome in snake bite. These include delayed presentation, occurrence of DIC, MODS, dehydration and usage of high dose ASV.