Association of preoperative frailty and prognostic nutritional index with postoperative delirium in elderly gastric cancer patients: A single-center observational study.

gastric cancer (GC) is a common malignancy in the elderly, and postoperative delirium (POD) is one of its significant complications, severely affecting postoperative recovery and quality of life. This study aims to explore the association of preoperative Modified Frailty Index (mFI)-assessed frailty and Prognostic Nutritional Index (PNI) with POD in elderly GC patients. A total of 164 elderly GC surgery patients were included in this study. Frailty was assessed using mFI, and PNI was calculated based on serum albumin levels and peripheral blood lymphocyte count. Multivariable logistic regression analysis was used to evaluate the association of frailty and PNI with POD, and the accuracy of both in predicting POD was analyzed using receiver operating characteristic curves. Additionally, the nonlinear relationship between PNI and POD was assessed using restricted cubic splines. Compared with the non-POD group, the POD group had older age, higher proportions of frailty (mFI ≥3), alcohol consumption history, intraoperative blood loss (≥200 mL), and longer surgical duration (≥3 hours). Furthermore, the levels of albumin, hemoglobin, lymphocytes, and PNI were lower in the POD group. In multivariable logistic regression analysis, frail patients had a 4.660 times higher risk of POD (P = .003), and for every 1 standard deviation increase in PNI, the risk of POD decreased by 36.2% (P <.001). The relationship between PNI and POD exhibited a significant nonlinear association (P = .004). The area under the curve of PNI was 0.884, which was superior to that of frailty (0.694, P <.001). Frailty and PNI are important predictive factors for POD in elderly GC patients.