Preoperative Serum Creatinine as an Independent Predictor of Intraoperative Hypothermia: Evidence from a Retrospective Cohort Study

Background Intraoperative hypothermia (IOH) is closely associated with various intraoperative and postoperative adverse events, and identifying high-risk patients preoperatively remains a significant challenge. In recent years, the proportion of surgical patients with renal insufficiency has been increasing, and their metabolic and thermoregulatory abnormalities contribute to a higher risk of IOH. This study aimed to investigate the predictive value of preoperative serum creatinine levels for intraoperative hypothermia, providing insight for risk assessment and preventive strategies. Methods This retrospective cohort study extracted data from 4,717 adult surgical patients in the Vital DB public database. The main exposure variable was preoperative serum creatinine, and the primary outcome was IOH, defined as a core temperature below 36.0°C at any intraoperative time point. A multivariable weighted logistic regression model was applied to evaluate the association between serum creatinine (as both a continuous and quartile-categorized variable) and IOH, adjusting for age, sex, ASA classification, surgery type, and intraoperative factors. Restricted cubic spline analysis was conducted to test for nonlinearity, while an XGBoost model with SHAP values was used to assess feature importance. Results Among all patients, the incidence of IOH was 96.2%. After adjustment, preoperative serum creatinine levels were significantly associated with IOH risk (adjusted odds ratio [aOR] = 3.44, 95% CI: 1.51–8.65). Compared with the lowest quartile group (Q1), patients in the highest quartile (Q4) showed a notably higher risk of IOH (aOR = 1.77, 95% CI: 1.09–2.94). The RCS analysis demonstrated a linear dose–response relationship (P for nonlinearity = 0.972). The XGBoost model confirmed serum creatinine as a key predictor with strong predictive value. Conclusion Elevated preoperative serum creatinine is an independent risk factor for IOH, exhibiting a linear positive association. This biomarker may serve as a practical preoperative tool for identifying high-risk IOH patients and guiding personalized temperature management strategies.