Snake Bite Envenomation in a Tertiary Care Centre.

BACKGROUND: In India, it is estimated that up to 20,000 people die annually from snake bites. The present study was carried to out to estimate the snake bite related epidemiology, predictors of severity, relationship between type of snake, clinical severity, complications, outcome and usage pattern of polyvalent anti snake venom (ASV) in a tertiary care center.

METHODS: All indoor patients admitted in our institute with definitive history of bite by a snake, with or without presence of fang marks, Evidence of cellulitis, acute onset of neurotoxicity or bleeding diathesis were serially recruited in the study.

RESULTS: The majority of cases were in the range of 21- 40 years (54.7%). There were 82.8% males (53/64), 17.2% females (11/64) and 60.9% (39/64) bites were during day time. Upper limb bites were seen in 34% (22/64) of the patients and lower limb bites in 54% (35/64), and axial body bites in 6%. There were 43.8% (28/64) vasculotoxic bites, 34.4% (22/64) neurotoxic bites and 20.3% (14/64) non-poisonous bites. Viper was the most common (9%) identified snake, followed by krait (5%). References from Rural Health Centers were 57.8% (57/64), 11% were from Primary health centers and rest from private sector. Anti snake venom (ASV) was received by 68.75% (44/64) patients before reaching tertiary care. Local swelling was present in 90.6% (58/64) patients, Systemic bleeding was seen in 35.9% (23/64), and Neuromuscular weakness in 35.9% (23/64) patients. Complications like Respiratory paralysis developed in 18.75% (12/64), Acute kidney injury in 12% (8/64), DIC in 9% (6/64), and hepatic involvement in 7% (5/64) of snake bite patients. Blood transfusion was required in 20.3% (13/64) p<0.001), 18.75% (12/64) required Mechanical ventilation (p=0.001), 4 received hemodailysis and 4 required ionotropic support (p<0.001). Improvement was seen in 57.8% (37/64), morbidity during hospital stay was seen in 39% (25/64) and 2 patients expired (3%). ASV was received within 4 hours in 67% (42/64) patients, 22.5% (14/64) received ASV between 4 to 24 hours and remaining after 24 hours (p=0.016). Total ASV requierment was 24.05 vials in patients who improved and 34.4vials in patients in Morbid group and 29.0 vials in mortality group (p>0.05). The SSS score amongst improved was 4.76 ± 2.46 whereas among morbid, it was 8.48 ± 1.75 and amongst expired, it was 8.5 ± 0.707 (p<0.05).

CONCLUSIONS: Patients requiring various supportive treatments like blood transfusion, Inotropes, Haemodialysis and Mechanical ventilation, had a statistically significant correlation with poor outcome. Early administration of ASV that is within 4 hours was, associated with better outcome. The total amount of ASV (in vials) had no a significant correlation with outcome. Snakebite Severity Score correlates significantly with early recovery in vasculotoxic snake bites (p=0.03).