VALIDATION OF 20 MINUTE WHOLE BLOOD CLOTTING TIME AFTER THE INITIATION OF ANTI SNAKE VENOM FOR COAGULOPATHY INDUCED BY HEMOTOXIC SNAKE BITE

Abstract

BACKGROUND: In this observational study, we have evaluated the validity of whole blood clotting time (WBCT) for the continuation of ASV treatment up to 18 hours by comparing PT/INR at baseline and at 12 hours and 18 hours for patients who have been initiated on ASV with the corresponding WBCT in patients with venom-induced coagulopathy.

METHODS: We prospectively included 46 patients with VIC received with ASV are included in the study who are eligible as inclusion and exclusion criteria and data regarding with WBCT20 , PT/INR results are collected.

RESULTS: To validate WBCT as a marker for the resolution of VIC and continuation of ASV for VICC WBCT-20 doesn't seem to be a good test. In our study Sensitivity of WBCT20 for coagulopathy (INR>1.4) at Baseline, 12h, and 18h was found to be 66.6%, 28.5%, and 18.1% respectively. Specificity of WBCT-20 for coagulopathy (INR>1.4) at Baseline, 12h, and 18h was found to be 28%, 72.70%, and 100% respectively. It showed that the sensitivity of WBCT-20 was coming down after ASV administration at 12 hours and 18 hours and the specificity of WBCT-20 was increasing progressively up to 18 hours after ASV administration. Because of the very poor sensitivity and the negative predictive value (NPV) of the test is poor WBCT is not an ideal test during the treatment phase of VICC with ASV PT/INR being a better indicator than WBCT during the treatment continuation phase.

CONCLUSION: WBC20 is a simple cost-effective and reliable test that can be performed at both primary and secondary/tertiary levels for the initiation of ASV. However, because of significant false negative and false positive results, INR is to be used wherever there is discordance between clinical evaluation and WBCT20. While WBCT20 is the only alternative is a resource-limited setting for monitoring treatment, in secondary/tertiary hospitals where INR measurement facilities are organized quickly with easier and fast access to reports monitoring, is better done by INR. Because of the good correlation between INR and ASV vials, further studies can explore the possibility of deciding the dose of founded ASV on quantitative report the of INR.