An Observational Trial to study the role of Thromboelastography in comparison with Conventional Coagulation Testing to assess the disease severity among Adult Patients with Snake Envenomation at a Tertiary Care Centre Hospital in Southern India

OBJECTIVES: 1. To compare Thromboelastography with conventional coagulation tests in patients presenting with snake envenomation. 2. To analyse the demographic, clinical and laboratory profiles; to identify the predictors of severe envenomation. METHODS: In this prospective observational cohort study with internal comparison, patients with snake envenomation presenting to CMC Hospital, Vellore between January 2013 and June 2014 fulfilling inclusion criteria were divided into low and high severity groups. Demographic, clinical and laboratory parameters were collected and analysed. We compared the two groups with respect to thromboelastography and conventional coagulation tests in identifying severe envenomation and clinical evidence of coagulopathy at admission. Correlation of thromboelastography with factors casuing coagulopathy and the risk factors that would predict severe envenomation were also analysed. Statistical analysis was done using STATA 13 software. RESULTS: A total of 72 patients were included: 32 with mild envenomation and 40 with severe envenomation. Sensitivities of thromboelastography (TEG), whole blood clotting time (WBCT), prothrombin time (PT) in identification of severe envenomation were 92%, 56% and 64%. Sensitivities of TEG, WBCT andPT in identification of clinical coagulopathy were 81.3%, 59.4% and 65.6%. The predictive value for a milder course when TEG was normal was 88.95% compared to WBCT and PT (56%, 62.5%). TEG was also highly sensitive in identification of thrombocytopenia (94.7%, p value: 0.0001). None of the risk factors analysed were found to be statistically significant on multivariate analysis in predicting severe envenomation. CONCLUSION: In patients with an acquired cause of coagulopathy such as snake envenomation, thromboelastography as a single test could prove to be a significant advance in the better and early identification of severe envenomation and coagulopathy