Nomogram For Predicting Risk Factors Of Fever In Patients With Negative Preoperative Urine Culture After RIRS

Purpose: To determine the risk factors for postoperative fever after retrograde intrarenal surgery(RIRS)in patients with negative preoperative urine culture(UC),and to establish a nomogram for predicting postoperative fever based on these risk factors.Methods: This study collected 322 patients with negative UC who received RIRS at the First Affiliated Hospital of Anhui Medical University from March 2019 to May 2022.The study population was divided into a fever group and a non-fever group.The risk factors of postoperative fever were determined by univariate and multivariate logistic regression analyses,and a nomogram was established.The nomogram was evaluated in terms of differentiation,calibration,and clinical practicability.Results: In this study,47(14.6%)patients developed a fever after surgery.Multivariate logistic regression analysis showed that for patients with negative preoperative urine culture,urinary leucocyte esterase(P = 0.005),operative time(P = 0.019),and intraoperative hypotension(P = 0.028)were independent risk factors of postoperative fever,and a nomogram was constructed according to the above variables.The area under the curve(AUC)calculated by receiver operating characteristic(ROC)analysis was 0.807(95% CI: 0.739-0.876),indicating good discrimination.The calibration curves showed good consistency,and the clinical decision curve analysis(DCA)showed the clinical applicability of the model.Conclusions: For patients with negative preoperative urine culture,urine leukocyte esterase,operative time,and intraoperative hypotension are independent risk factors of postoperative fever.The new nomogram can better assess the risk of infection in patients with negative UC after RIRS.