Evaluation of severe rhabdomyolysis on day 30 mortality in trauma patients admitted to intensive care: a propensity score analysis of the Traumabase registry

Background Traumatic rhabdomyolysis (RM) is common and associated with the development of acute kidney injury and potentially with other organ dysfunctions. Thus, RM may increase the risk of death. The primary objective was to assess the effect of severe RM (Creatine Kinase [CK] > 5000 U/L) on 30-day mortality in trauma patients using a causal inference approach. Methods In this multicenter cohort study conducted in France using a national major trauma registry (Traumabase) between January 1, 2012, and July 1, 2023, all patients admitted to a participating major trauma center hospitalized in intensive care unit (ICU) and with CK measurement were included. Confounding variables for both 30-day mortality and exposure were used to establish a propensity score. A doubly robust approach with inverse treatment weighting enabled the calculation of the average treatment effect on the treated (ATT). Analyses were performed in the overall cohort as well as in two subgroups: hemorrhagic shock subgroup (HS) and traumatic brain injury subgroup (TBI). Sensitivity analyses were conducted. Results Among the 8592 patients included, 1544 (18.0%) had severe RM. They were predominantly males (78.6%) with median [IQR] age of 41 [27-58] years and severely injured (ISS 20 [13 - 29]) mainly from blunt trauma (90.8%). In the entire cohort, the ATT, expressed as a risk difference, was 0.073 [-0.054 to 0.200]. Considering the 1311 patients in the HS subgroup, the ATT was 0.039 [0.014 to 0.063]. As in the overall cohort, there was no effect on mortality in the TBI subgroup. Severe RM was associated with greater severity of trauma and more complications (whether related to renal function or not) during the ICU stay. Mortality due to multiorgan failure (39.9% vs 12.4%) or septic shock (2.6% vs 0.8%) was more frequent among patients with severe RM. Conclusions Severe RM was not associated with 30-day mortality considering the overall cohort. However, it was associated with a 4.0% increase in 30-day mortality among patients with concurrent hemorrhagic shock. Severe RM plays a significant role in ICU morbidity.