Serum procalcitonin levels are associated with rhabdomyolysis following exertional heatstroke: an over 10-year intensive care survey.

Background: Heatstroke has become a common emergency event in hospitals. Procalcitonin (PCT) is used as a biomarker of infection in the emergency department (ED), but its role in rhabdomyolysis (RM) following exertional heatstroke (EHS) remains unclear.

Methods: A retrospective cohort study enrolled patients with EHS from the intensive care unit (ICU). We collected RM biomarkers, inflammation markers, critical disease scores at admission, 24 h, 48 h, and discharge, and 90-day mortality. Correlation analysis, linear regression and curve fitting were used to identify the relationship between PCT and RM.

Results: A total of 162 patients were recruited and divided into RM (n=56) and non-RM (n=106) groups. PCT was positively correlated with myoglobin (Mb), acute hepatic injury, disseminated intravascular coagulation (DIC), Sequential Organ Failure Assessment (SOFA) score, and Acute Physiology and Chronic Health Evaluation II (APACHE II) score, with correlation coefficients of 0.214, 0.237, 0.285, 0.454, and 0.368, respectively (all P<0.05). Interestingly, the results of curve fitting revealed a nonlinear relationship between PCT and RM, and a two-piecewise linear regression model showed that PCT was related to RM with an odds ratio of 1.3 and a cut-off of <4.6 ng/mL. Survival analysis revealed that RM was associated with higher mortality compared to non-RM cases (P=0.0093).

Conclusion: High serum PCT concentrations are associated with RM after EHS in critically ill patients. Elevated PCT concentrations should be interpreted cautiously in patients with EHS in the ED.