Persistent thrombocytopaenia as an independent risk factor for 28-day mortality and multiorgan failure in exertional heatstroke: a retrospective study of 217 patients.

Abstract

Background: Thrombocytopaenia is a known predictor of poor outcomes in trauma and sepsis patients, its prognostic role in exertional heatstroke (EHS) remains underexplored. This study aimed to evaluate the association between persistent thrombocytopaenia and mortality in critically ill EHS patients.

Methods: In this retrospective cohort study, we analyzed data from 217 EHS patients admitted to the intensive care unit (ICU) between November 2009 and October 2023. Demographic, biochemical (baseline, 24 h, and 48 h), and inflammatory marker data were collected. Persistent thrombocytopaenia was defined as a platelet count <100 × 10⁹/L at both 24 h and 48 h postadmission. Multivariate logistic regression identified predictors of 28-day mortality, and Kaplan-Meier survival curves with log-rank tests were used to compare outcomes between groups.

Results: Among the 217 patients, 19 (8.8%) patients died within 28 days. Nonsurvivors presented significantly worse liver/kidney function, coagulopathy (DIC incidence: 89.5% vs. 26.8%, p < 0.001), and AKI incidence (100% vs. 38.4%, p < 0.01). The platelet counts in nonsurvivors were markedly lower than those in survivors at admission (71 vs. 166 × 10⁹/L), 24 h (49 vs. 134 × 10⁹/L), and 48 h (56 vs. 131 × 10⁹/L) (all p < 0.001). Persistent thrombocytopaenia (63 patients, 29.0%) independently predicted mortality (adjusted OR = 17.44, 95% CI: 4.76-63.86; p < 0.001) and was correlated with higher DIC (84.1% vs. 11.0%, p < 0.001) and AKI (63.5% vs. 35.7%, p < 0.001) rates. Survival analysis confirmed significantly increased 28-day mortality in thrombocytopaenia patients (25.4% vs. 1.9%, p < 0.001).

Conclusion: Persistent thrombocytopaenia within 48 h of ICU admission is a robust predictor of mortality and multiorgan dysfunction in patients with EHS.