Prognostic significance of nadir platelet count in patients with heatstroke: A multi-center retrospective study

Background: Heatstroke (HS), associated with the early activation of the coagulation system and frequently presenting with thrombocytopenia, poses a significant healthcare challenge. Understanding the relationship of nadir platelet count (PLT) within 24 h for adverse outcomes in HS patients is crucial for optimizing management strategies. Methods: This retrospective cohort study, conducted in six tertiary care hospitals, involved patients diagnosed with HS and admitted to the emergency departments. The primary and secondary outcomes included inhospital mortality and various acute complications, respectively, with logistic regression models utilized for assessing associations between nadir PLT and outcomes. The PLT count change curve was described using a generalized additive mixed model (GAMM), with additional analyses involving body temperature (BT) at 2 h also conducted. Results: Of the 152 patients included, 19 (12.5%) died in-hospital. The median nadir PLT within 24 h was 99.5 (58.8-145.0)*10<^>9/L. Notably, as a continuous variable (10*10<^>9/L), nadir PLT was significantly associated with in-hospital mortality (OR 0.76; 95% CI 0.64-0.91; P = 0.003) and other adverse outcomes like acute kidney and liver injury, even after adjustment for confounders. GAMM revealed a more rapid and significant PLT decline in the non-survival group over 24 h, with differential PLT dynamics also observed based on BT at 2 h. Conclusions: Nadir PLT within 24 h were tied to in-hospital mortality and various adverse outcomes in HS patients. Early effective cooling measures demonstrated a positive impact on these associations, underscoring their importance in patient management. (c) 2024 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).