Incidence and risk factors of postoperative delirium in patients undergoing elective lung cancer surgery : a retrospective study using the national inpatient sample database

Lung cancer is the world's deadliest cancer, and surgery offers cure for over 75% of patients. However, postoperative delirium (POD) impairs recovery, accelerates cognitive decline, and increases mortality. Despite evidence that multicomponent prevention can avert 30-40% of POD, its incidence and predictors in lung cancer surgery remain under-studied.

We conducted a retrospective cohort study of adults (≥ 18 years) undergoing elective lung cancer surgery resection from 2010 to 2019 using the U.S. National Inpatient Sample. Emergency admissions, rib fractures, and preexisting delirium or dementia were excluded. POD was identified by ICD-9/10 codes. We extracted demographics, comorbidities, perioperative complications, length of stay, and costs. Wilcoxon rank-sum and χ² tests compared groups, and univariable and multivariable logistic regression-with stepwise selection and Bonferroni correction-identified independent POD predictors. Analyses were performed in R, with P < 0.05.

Among 30,813 resections, 1,499 patients (4.86%) developed POD. Age ≥ 71 years (OR 2.10; 95% CI 1.75-2.51) and 61-70 years (OR 1.59; 1.35-1.88), female sex (OR 1.12; 1.01-1.24), teaching-hospital status (OR 1.38; 1.21-1.57), and more extensive resections (lobectomy OR 1.43; 1.28-1.60; pneumonectomy OR 2.58; 2.06-3.23) increased POD risk, whereas urban hospitals were protective (OR 0.71; 0.55-0.91). Preoperative neurological disorders (OR 5.62; 5.02-6.29), psychoses (OR 1.62; 1.35-1.95), fluid-electrolyte disorders (OR 1.27; 1.14-1.42), and hypertension (OR 1.21; 1.08-1.36) were independent predictors. Postoperative arrhythmia, deep-vein thrombosis, stroke, shock, urinary infection, and hypoxemia further elevated risk; chronic pulmonary disease and respiratory failure were protective.

POD complicates nearly 5% of lung cancer resections. Key demographic, clinical, and institutional factors identify high-risk patients who may benefit from targeted, multicomponent prevention strategies in thoracic surgery.