The Association Between Preoperative Neutrophil–Lymphocyte Ratio and Febrile Urinary Tract Infection in Patients Treated by Percutaneous Nephrolithotomy

Objective: This study aimed to assess the association between preoperative neutrophil–lymphocyte ratio (NLR) and febrile urinary tract infection (fUTI) in patients who underwent percutaneous nephrolithotomy (PCNL).
Patients and Methods: The clinical data of patients who underwent PCNL at our hospital between March 2020 and May 2023 were retrospectively analyzed. According to whether fUTI occurs after operation, collected data were divided to the patients into fUTI and non-fUTI. Univariate analysis, relative operating characteristic (ROC) curves and multivariate logistic regression analysis were performed on the data.
Results: A total of 405 patients were enrolled in the study. The procedure was successfully performed in all patients, and the incidence of fUTI was 8.4% (34/405). Eight patients eventually developed sepsis, and the incidence of sepsis in fUTI patients was 23.5%. The result shows a significant correlation between NLR and fUTI (95% confidence interval [CI],1.21– 1.83, Odds ratio [OR]=1.49, p< 0.001). The predictive ability of NLR on the occurrence of fUTI was assessed by plotting relative operating characteristic (ROC) curves. The area under the curve (AUC) in the ROC curve for NLR was 0.718 according to the Youden index, and the best cut-off value of NLR was 2.71. Furthermore, logistic multiple regression model adjustment was carried out to further confirm the robustness of the relationship between NLR and fUTI. The results indicated robustness regardless of whether NLR was a continuous variable or a categorical variable.
Conclusion: NLR can be used as a simple and effective preoperative indicator for the prediction of fUTI in patients undergoing PCNL.

Keywords: percutaneous nephrolithotomy, febrile urinary tract infection, neutrophil–lymphocyte ratio