The association of standard base excess upon emergency admission with outcomes in patients with heat stroke

Standard base excess (SBE) is a quick and effective tool to identify acid-base disorders in critically ill patients, independent of respiratory factors. The predictive value of SBE for adverse outcomes in patients with heat stroke (HS) is still unclear. This study aimed to explore the prognostic significance of SBE for in-hospital mortality and other adverse outcomes in patients with HS. A retrospective, observational multicenter cohort study with consecutive patients between 2021 and 2022 was conducted. The SBE was performed upon emergency department (ED) admission. The primary outcome was in-hospital mortality. Secondary outcomes included the use of vasoactive drugs in the ED, admission to the ICU, acute kidney failure, acute heart failure, acute respiratory failure, sepsis, and coagulation impairment. Logistic regression models and receiver operating characteristic (ROC) curves were used to estimate the association of SBE with outcomes in HS patients. Interaction and stratified analyses were also conducted. The median level of SBE was −4.70 (−8.05– −1.55) mmol/L. Overall hospital mortality in these 151 HS patients was 12.58%. SBE was independently associated with hospital mortality (OR 0.81, 95% CI 0.70–0.95, P = 0.011). Age and HS type played interactive roles in the relationship between SBE and in-hospital mortality. The OR between SBE and hospital mortality was 0.5 (95% CI, 0.3–0.9; p < 0.018) in classic HS participants and 0.62 (95% CI, 0.45–0.87; p = 0.005) in participants aged >65 years. The AUC of SBE to predict in-hospital mortality was 0.868 (95% CI: 0.704–0.962) and 0.883 (95% CI: 0.750–0.951) in these two groups, respectively. SBE was significantly associated with admission to the ICU, acute kidney failure, acute respiratory failure, sepsis, and coagulation impairment. SBE upon emergency admission was significantly associated with adverse outcomes in patients with HS.