To establish the risk factor model of postoperative delirium in elderly patients with gastric cancer and verify its application effect.

A total of 390 elderly patients with gastric cancer admitted to Xuzhou Central Hospital from March 2021 to March 2024 were included in the training group (n=273) and verification group (n=117) according to a ratio of 7∶3. The occurrence of postoperative delirium was evaluated, and the difference of clinical data between the postoperative delirium occurrence and no postoperative delirium was compared in the training group. Multivariate Logistic regression analysis was used to summarize the risk factors of postoperative delirium in elderly patients with gastric cancer, and the risk factors were incorporated into the Nomogram prediction model. The receiver operating characteristic (ROC) curve was drawn to predict the occurrence of postoperative delirium in the validation group, and the calibration degree of the model was verified by Bootstarp method and clinical decision curve analysis (DCA).

Among the 390 included patients, 80 patients developed delirium after the operation, with an incidence rate of 20.51%. In the training group, those with postoperative delirium were classified as the delirium group (n=50), and the remaining 223 cases were classified as the non-delirium group. There were statistically significant differences in preoperative hypertension history, respiratory rate (RR), creatinine value, surgical methods, operation time, intraoperative blood loss, mechanical ventilation, and acute physiology score (APS) Ⅲ between the delirium group and the non-delirium group (P<0.05). Logistic multivariate analysis showed that preoperative history of hypertension, RR level, creatinine value, surgical method, operation time, intraoperative blood loss, mechanical ventilation, and APS Ⅲ score were all independent risk factors affecting postoperative delirium in elderly patients with gastric cancer (P<0.05). The areas under the curve of the model applied in the training group and the validation group were 0.854 (95% CI 0.812-0.896) and 0.812 (95% CI 0.763-0.861), respectively. The sensitivity and specificity applied in the validation group were 80.53% (95% CI 73.7-86.2%, 81.53% (95% CI 75.0-87.0%), and presented a positive net benefit within the full threshold range (5-95%).

The risk of postoperative projection in elderly patients with gastric cancer is higher, and it is related to preoperative hypertension history, RR level, creatinine value, operation method, operation time, intraoperative blood loss, mechanical ventilation, APS Ⅲ score and other factors, and the prediction model established based on the above factors can provide a reliable reference for the assessment of postoperative delirium reduction in elderly patients with gastric cancer.