Objective To investigate the predictive value of preoperative nutritional status and frailty on postoperative delirium (POD) in elderly patients undergoing non-cardiac surgery.

Methods Clinical data of 376 elderly patients undergoing non-cardiac surgery in our hospital from January 2020 to December 2022 were retrospectively collected via electronic medical record system, and were divided into POD group(80 cases) and non-POD group(296 cases) according to whether they developed POD within 5 d after surgery or not. Risk factors for POD were analyzed using multi-factor Logistic regression, and the value of malnutrition and debilitation in predicting POD was quantitatively assessed using receiver operating characteristic (ROC) curves.

Results Univariate analysis showed that the proportions of patients aged over 70 years old, with diabetes, junior high school education or below, preoperative frailty and moderate to severe malnutrition in the POD group were higher than that in non-POD group(P < 0.05). Multifactor Logistic regression analysis showed that age>70 years (OR=1.398; 95%CI, 1.044 to 1.872), preoperative frailty (OR=1.706; 95%CI, 1.238 to 2.349) and preoperative moderate to severe malnutrition (OR=1.632; 95%CI, 1.282 to 2.079) were independent risk factors for POD in elderly patients with non-cardiac surgery. ROC curve showed that the area under the curve (AUC) of preoperative debilitation combined with moderate to severe malnutrition was 0.801 (95%CI, 0.754 to 0.847) for predicting POD in elderly patients undergoing non-cardiac surgery, which had better predictive efficacy than a single indicator.

Conclusion Preoperative malnutrition and frailty are correlated with POD in elderly patients undergoing non-cardiac surgery, and the combined application can predict the risk of developing POD, identify high-risk population in early stage and implement targeted interventions to optimize perioperative management.