A nomogram for predicting postoperative urosepsis following retrograde intrarenal surgery in upper urinary calculi patients with negative preoperative urine culture

Retrograde intrarenal surgery (RIRS) is one of the main surgical methods for upper urinary calculi, but severe complications of infection may occur after surgery. This study aimed to establish and validate a preoperative nomogram for predicting postoperative urosepsis following retrograde intrarenal surgery to treat upper urinary calculus in patients with a negative preoperative urine culture. We retrospectively recruited 1767 patients with negative preoperative urine cultures who underwent retrograde intrarenal surgery to treat upper urinary calculi from January 2017 to April 2022. The independent risk factors for urosepsis include a solitary kidney, positive urine nitrite, operative time ≥ 75 min, history of recurrent urinary tract infections, and history of diabetes were identified by univariate analysis and multivariate binary logistic regression analysis, which construct a nomogram. The receiver operating characteristic curve of the nomogram for predicting urosepsis was 0.887 in the training cohort and 0.864 in the validation cohort, respectively. The calibration curve and decision curve analysis demonstrated great consistency and clinical utility of the nomogram. Therefore, the nomogram combining preoperative independent risk factors can predict the probability of a postoperative urosepsis following retrograde intrarenal surgery in patients with a negative preoperative urine culture, which could help urologists take preventive measures in advance after surgery to avoid more serious complications of infection.