Risk factors and effect of postoperative delirium on adverse surgical outcomes in older adults after elective abdominal cancer surgery in Taiwan

Background: Postoperative delirium (POD) is a common complication in older adults, with unknown epidemiology and effects on surgical outcomes in Asian geriatric cancer patients. This study evaluated incidence, risk factors, and association between adverse surgical outcomes and POD after intra-abdominal cancer surgery in Taiwan. Methods: Overall, 345 patients aged ≥65 years who underwent elective abdominal cancer surgery at a medical center in Taiwan were prospectively enrolled. Delirium was assessed daily using the Confusion Assessment Method. Univariate and multivariate logistic regression analyses investigated risk factors for POD occurrence and estimated the association with adverse surgical outcomes. Results: POD occurred in 19 (5.5%) of the 345 patients. Age ≥73 years, Charlson comorbidity index ≥3, and operative time >428 min were independent predictors for POD occurrence. Patients presenting with one, two, and three risk factors had 4.1-fold (95% confidence interval [CI], 0.4–35.8, p = 0.20), 17.4-fold (95% CI, 2.2–138, p = 0.007), and 30.8-fold likelihood (95% CI, 2.9–321, p = 0.004) for POD occurrence, respectively. Patients with POD had a higher probability of prolonged hospital stay (adjusted odds ratio [OR] 2.8; 95% CI, 1.0–8.1; p = 0.037), intensive care stay (adjusted OR: 3.9; 95% CI, 1.5–10.5; p = 0.008), 30-day readmission (adjusted OR 3.1; 95% CI, 1.1–9.7; p = 0.039), and 90-day postoperative death (adjusted OR: 4.2; 95% CI, 1.0–17.7; p = 0.041). Conclusion: POD occurrence was significantly associated with adverse surgical outcomes in geriatric patients undergoing elective abdominal cancer surgery, highlighting the importance of early POD identification in geriatric patients to improve postoperative care quality.