Comparing modified Lee and White method against 20-minute whole blood clotting test as bedside coagulation screening test in snake envenomation victims

Appu Suseel; Siju V Abraham; Sarah Paul; Maglin Monica Lisa Tomy; Aboobacker Mohamed Rafi

doi:10.1590/1678-9199-JVATITD-2022-0088

Comparing modified Lee and White method against 20-minute whole blood clotting test as bedside coagulation screening test in snake envenomation victims

J Venom Anim Toxins Incl Trop Dis. 2023 Jun 19:29:e20220088. doi: 10.1590/1678-9199-JVATITD-2022-0088. eCollection 2023.

Authors

Appu Suseel¹, Siju V Abraham¹, Sarah Paul¹, Maglin Monica Lisa Tomy², Aboobacker Mohamed Rafi²

Affiliations

¹ Department of Emergency Medicine, Jubilee Mission Medical College and Research Institute, Thrissur, Kerala, India.
² Department of Immunohematology and Blood Transfusion, Jubilee Mission Medical College and Research Institute, Thrissur, Kerala, India.

PMID: 37342654
PMCID: PMC10278964
DOI: 10.1590/1678-9199-JVATITD-2022-0088

Abstract

Background: Twenty-minute whole blood clotting test (20WBCT) and Modified Lee and White (MLW) method are the most routinely employed bedside tests for detecting coagulopathic snake envenomation. Our study compared the diagnostic utility of MLW and 20WBCT for snakebite victims at a tertiary care hospital in Central Kerala, South India.

Methods: This single-center study recruited 267 patients admitted with snake bites. 20WBCT and MLW were performed simultaneously at admission along with the measurement of Prothrombin Time (PT). The diagnostic utility of 20WBCT and MLW was determined by comparing the sensitivity (Sn), specificity (Sp), positive and negative predictive values, likelihood ratios, and accuracy at admission with an INR value > 1.4.

Results: Out of 267 patients, 20 (7.5%) patients had VICC. Amongst those who had venom-induced consumption coagulopathy (VICC), MLW was prolonged for 17 patients, (Sn 85% 95% confidence interval [CI]: 61.1-96.0) whereas 20WBCT was abnormal for 11 patients (Sn 55%, 95% CI: 32.04-76.17). MLW and 20WBCT were falsely positive for the same patient (Sp 99.6%, 95% CI: 97.4-99.9%).

Conclusion: MLW is more sensitive than 20WBCT to detect coagulopathy at the bedside amongst snakebite victims. However, further studies are necessary for standardizing bedside coagulation tests in snakebite cases.

Keywords: 20-minute whole blood clotting test; Conventional coagulation tests; Modified Lee and White method; Prothrombin time; Venom-induced consumption coagulopathy.