Impact of Prognostic Nutritional Index on Postoperative Pulmonary Complications in Radical Cystectomy: A Propensity Score-Matched Analysis

Background Radical cystectomy is a standard treatment for muscle-invasive bladder cancer but frequently entails postoperative pulmonary complications (PPCs). Nutrition is closely associated with postoperative outcomes. Therefore, we evaluated the impact of preoperative prognostic nutritional index (PNI) on PPCs in radical cystectomy. Methods PNI was calculated as 10 x (serum albumin) + 0.005 x (total lymphocyte count). The risk factors for PPCs were evaluated using multivariate logistic regression analysis. A receiver operating characteristic curve analysis of PNI was performed, and an optimal cut-off value was identified. Propensity score-matched analysis was used to determine the impact of PNI on PPCs. Postoperative outcomes were also evaluated. Results PPCs occurred in 112 (13.6%) of 822 patients. Multivariate logistic regression analysis identified PNI, age, and serum creatinine level as risk factors. The area under the receiver operating characteristic curve of PNI for predicting PPCs was 0.714 (optimal cut-off value: 45). After propensity score matching, the incidence of PPCs in the PNI <= 45 group was significantly higher compared with the PNI > 45 group (20.8% vs. 6.8%;p < 0.001), and PNI <= 45 was associated with a higher incidence of PPCs (odds ratio 3.308, 95% confidence interval 1.779-6.151;p < 0.001). The rates of intensive care unit admission and prolonged (> 2 days) stay thereof were higher in patients who developed PPCs. Conclusions Preoperative PNI <= 45 was associated with a higher incidence of PPCs in radical cystectomy, suggesting that PNI provides useful information regarding pulmonary complications after radical cystectomy.