Construction and validation of the nomogram predictive model for post-percutaneous nephrolithotomy urinary sepsis.

ABSTRACT

OBJECTIVE: This study aimed to construct and validate a simple and accurate clinical nomogram for predicting the occurrence of post-percutaneous nephrolithotomy sepsis, aiming to assist urologists in the early identification, warning, and early intervention of urosepsis, and to provide certain evidence-based medicine basis. METHODS: This study included patients who underwent PCNL surgery due to kidney or upper ureteral stones at the Department of Urology, Affiliated Hospital of Zunyi Medical University, from January 2019 to September 2022. This study utilized univariate and multivariate logistic regression analysis to screen and evaluate the risk factors for sepsis and construct a predictive model. An evaluation was performed using the receiver operating characteristic curve, calibration curve, and decision curve analysis curve. All statistical analyses were conducted using R version 4.2. RESULTS: A total of 946 patients who underwent post-PCNL were included in this study, among whom 69 patients (7.29%) developed post-PCNL urinary sepsis. Multiple-factor logistic regression analysis identified four independent risk factors associated with post-PCNL urinary sepsis, including positive urinary nitrite (OR = 5.9, P < 0.001), positive urine culture (OR = 7.54, P < 0.001), operative time ≥ 120 min (OR = 20.93, P = 0.0052), and stone size ≥ 30 mm (OR = 13.81, P = 0.0015). The nomogram model demonstrated good accuracy with an AUC value of 0.909, and in the validation cohort, the AUC value was 0.922. The calibration curve indicated a better consistency between the predictive line chart and the actual occurrence of post-PCNL urinary sepsis. The decision curve analysis curve showed favorable clinical utility. CONCLUSION: Preoperative positive urine culture, positive urinary nitrite, operative time ≥ 120 min, and stone size ≥ 30 mm are independent risk factors for developing post-PCNL urinary sepsis. The constructed line chart based on these factors effectively assesses the risk of urinary sepsis in patients after PCNL.