Prognostic indicators in patients with snakebite: analysis of two-year data from a township hospital in central Myanmar.

BACKGROUND

Rural people seek medical treatment for snakebite at peripheral health care facilities. Hence, identification of the characteristics, which can be used at peripheral levels of health care as reliable predictors of mortality, are required.

METHODS

Hospital records of 101 patients (70 males and 31 females) with age ranging from 3 to 80 years, admitted to Nahtogyi township hospital in central Myanmar during January 2005 to December 2006 were reviewed retrospectively. Binary logistic regression was used for estimating odds ratio (OR) and 95% Confidence Interval (CI) for various prognostic indicators of mortality.

RESULTS

Almost all snakebites were on extremities; more in legs (62%) than hands (37%). Most (52.5%) bites occurred in the morning (4 am to noon). Mean (SD) time for bite-to-hospital and bite-to-injection of anti-snake venom (ASV) was 134.6 (78.6) and 167 (187.8) minutes respectively. Eleven cases (10.9%) had died. Case fatality ratio (CFR) was significantly higher in 39 patients with un-clotted blood as compared to 62 patients with clotted blood (25.6% vs 1.6%, p <0.0005). Significantly higher CFR was observed in 49 patients who received ASV in >2 hours after the bite compared to 52 cases who received ASV within two hours (9.9% vs 0.9%, p <0.0001). Odds ratio of fatality were higher among those who had urine output of <400 ml in the first 24 hours (OR 26.4; 95% CI 2.4 to 288.3), un-clotted blood (OR 4.6; 95% CI 0.3 to 66.7), bite-to-injection time of >2 hours (OR 4; 95% CI 0.1 to 219.8) bite-to-hospital time of >2 hours (OR 3.1; 95%CI 0.1 to 136.3) and bites in the morning (OR 2; 95% CI 0.3 to 16.0).

CONCLUSIONS

Clinical parameters could be used by healthcare providers to identify snakebite patients for referral, who may have fatal outcome.