A Dynamic Online Nomogram for Predicting Postoperative Acute Kidney Injury After Sleeve Gastrectomy

BACKGROUND Acute kidney injury (AKI) is a common but often under-recognized complication after sleeve gastrectomy. Intraoperative hemodynamic instability, particularly systolic blood pressure variability, has emerged as a potentially modifiable risk factor contributing to postoperative AKI. The aim was to identify key predictors of postoperative AKI and to develop a dynamic online nomogram for individualized risk prediction, with a specific focus on intraoperative systolic blood pressure variability. MATERIAL AND METHODS We retrospectively analyzed perioperative data from 1386 adult patients who underwent laparoscopic sleeve gastrectomy. Independent predictors of postoperative AKI were identified using multivariable logistic regression. A nomogram was constructed based on the final model and evaluated using discrimination, calibration, internal bootstrap validation (1000 resamples), and decision curve analysis. A web-based dynamic version of the nomogram was developed for clinical application. RESULTS Five variables - American Society of Anesthesiologists (ASA) physical status classification, baseline estimated glomerular filtration rate, hemoglobin level, intraoperative systolic blood pressure variability expressed as the coefficient of variation, and total intraoperative infusion volume - were independently associated with postoperative AKI. The nomogram demonstrated good discrimination (area under the curve (AUC)=0.716, satisfactory calibration (mean absolute error=0.006), and clinical utility on decision curve analysis. A dynamic web-based version of the model was made available to support individualized risk assessment. CONCLUSIONS This study integrates intraoperative systolic blood pressure variability into a dynamic, web-based prediction model for postoperative AKI after sleeve gastrectomy. The proposed nomogram provides a practical tool for early risk stratification and may facilitate individualized perioperative management aimed at renal protection.