Objective: To identify independent risk factors for postoperative delirium (POD) in patients with colorectal cancer and to construct an individualized prediction model. Methods: A total of 385 colorectal cancer patients between January 2019 and January 2024 (training set), 232 males and 153 females, aged 60-85 years, BMI 15.0-32.0 kg/m 2, ASA physical status Ⅰ-Ⅲ, who underwent laparoscopic radical colorectal cancer surgery under general anesthesia were included, and 130 patients between February 2024 and January 2025 were selected as the validation set. POD was assessed using the confusion assessment method within 7 days after surgery, and patients were divided into two groups: the POD group and the non-POD group. Data were collected including education level, MMSE score on the day before surgery, smoking history, alcohol abuse, tumor stage, emergency surgery, combined organ resection, operative duration, perioperative blood transfusion, intraoperative hypotension, intraoperative medication use, postoperative intensive care unit (ICU), and postoperative patient-controlled analgesia. Preoperative laboratory parameters obtained on the day before surgery included hemoglobin (Hb), white blood cell count (WBC), C-reactive protein (CRP), albumin-to-fibrinogen ratio (AFR), neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), prognostic nutritional index (PNI), and modified frailty index (mFI). Multivariate Logistic regression analysis was used to identify independent risk factors for POD, and a nomogram prediction model was constructed and evaluated using R 4.4.1 software. Receiver operating characteristic (ROC) curve, calibration curve and decision curve analysis (DCA) were used for validation. Results: In this study, 51 patients in training set (13.2%) developed POD within 7 days after surgery, while 19 patients in validation set (14.6%). Compared with the non-POD group, the POD group in both training and validation sets exhibited significantly higher age, proportion of alcohol abuse, emergency surgery, postoperative ICU transfer, elevated CRP levels, NLR, and mFI, as well as prolonged operative time, while AFR and PNI were significantly lower (P< 0.05). Multivariate Logistic regression analysis in training set identified the following independent risk factors for POD after laparoscopic radical colorectal cancer surgery: advanced age (OR = 1.107, 95% CI 1.015-1.208, P = 0.022), prolonged operative time (OR = 1.019, 95% CI 1.006-1.033, P = 0.005), elevated NLR (OR = 25.939, 95% CI 9.135-73.635, P < 0.001), and elevated mFI (OR = 9.097, 95% CI 3.816-21.688, P < 0.001). Increased AFR (OR = 0.606, 95% CI 0.414-0.888, P = 0.010) and increased PNI (OR = 0.896, 95% CI 0.820-0.981, P = 0.017) were independent protective factors. The nomogram prediction model constructed based on these factors in training set demonstrated an AUC value of 0.902 (95% CI 0.866-0.939), while the validation set demonstrated an AUC of 0.933 (95%CI 0.891-0.975). Conclusion: The nomogram model constructed based on age, operative time, AFR, NLR, PNI, and mFI can effectively predict the occurrence of POD in colorectal cancer patients. |