The Usefulness of Platelet Distribution Width and Platelet Distribution Width to Lymphocyte Ratio in Predicting Severity and Outcomes in Patients with Snakebite.

Abstract

Tissue damage, inflammatory response, and hematologic abnormalities may occur in snakebite envenomation. This study aimed to evaluate the predictive ability of platelet distribution width (PDW) and platelet distribution width to lymphocyte ratio (PDWLR) in the severity and outcome of envenomation in patients with snakebites in the emergency department (ED). All adult patients admitted to the ED after a snakebite were retrospectively evaluated. Patients were classified according to the severity of envenomation. The relationship between the PDW and PDWLR and envenomation severity and patient outcomes was analyzed. Multivariate logistic regression analysis was performed to determine the predictors of severe envenomation. Results were presented as 95% CIs with odds ratios. Statistical significance was accepted at P<0.05. Envenomation was classified as none/minimal in 42 patients and moderate/severe in 29. PDW and PDWLR were significantly higher in the moderate/severe group (P=0.016 and P<0.001, respectively). Cut-off values of 16.5 for PDW and 6.15 for PDWLR were related to more severe envenomation (area under the curve 0.67, 95% CI 0.55-0.78 and area under the curve 0.85, 95% CI: 0.74-0.92, respectively). Blood product replacement, thrombocytopenia, hematologic abnormality, advanced local findings, compartment syndrome/fasciotomy, antivenom dosing, and moderate/severe envenomation were associated with PDWLR >6.15 (P<0.05). In multivariate analysis, PDWLR (odds ratio 1.19 [95% CI 1-1.4]; P=0.04) was an independent predictor of severe envenomation. Higher PDW and PDWLR were associated with severe envenomation in patients with snakebites in the ED. PDWLR may be used as a predictor of severe envenomation and adverse outcomes.