The role of early warning scores in predicting envenomation severity and adverse clinical outcomes in snake bites

This study aimed to examine the role of early warning scores (RAPS, REMS, MEWS, WPSS, and NEWS) in predicting envenomation severity and adverse clinical outcomes (ACO) in patients presenting to the emergency department (ED) following a snake bite. This retrospective observational study analyzed data from patients who presented to the ED of a university hospital between January 1, 2014, and December 31, 2024. ACO was defined as the need for high-dose antivenom (AV) treatment, blood product transfusion, and prolonged hospitalization. The discriminative performance of the scores for envenomation severity and ACO was assessed using receiver operating characteristic (ROC) curve analysis. Confidence intervals (95%) for differences between independent curves were provided. A total of 84 patients with complete data were included in the study. 47.6% of the patients required admission to the ward, and 34.5% required intensive care unit admission. No deaths occurred. In distinguishing Grade 2–3 envenomation severity, WPSS (AUC: 0.890 [0.762–0.963]), MEWS (AUC: 0.854 [0.718–0.940]), NEWS (AUC: 0.852 [0.716–0.939]), and RAPS (AUC: 0.750 [0.600-0.866]) scores demonstrated high AUC values, accompanied by wide confidence intervals. For predicting the need for high-dose AV, WPSS (AUC: 0.687 [0.570–0.783]), NEWS (AUC: 0.683 [0.570–0.780]), MEWS (AUC: 0.662 [0.550–0.760]), and RAPS (AUC: 0.613 [0.500–0.720]); for predicting the need for blood product transfusion, RAPS (AUC: 0.680 [0.569–0.778]), NEWS (AUC: 0.670 [0.559–0.769]), and WPSS (AUC: 0.669 [0.558–0.768]), for predicting prolonged hospitalization, the performance of all scores, including WPSS (AUC: 0.674 [0.563–0.773]), NEWS (AUC: 0.673 [0.562–0.771]), REMS (AUC: 0.651 [0.539–0.752]), MEWS (AUC: 0.637 [0.525–0.739]), and RAPS (AUC: 0.629 [0.517–0.732]), was statistically significant ( p < 0.05), although their predictive performance was observed to be weak. Although WPSS, MEWS, NEWS, and RAPS showed high AUC values for distinguishing Grade 2–3 envenomation, these findings should be interpreted cautiously because of the small number of severe cases and wide confidence intervals. For ACOs, the evaluated EWSs demonstrated limited-to-moderate discriminatory ability and should be considered complementary rather than standalone clinical decision-making tools. Further studies with larger datasets are needed to validate these findings.