The Role of Delirium on Short- and Long-Term Postoperative Outcomes Following Major Gastrointestinal Surgery for Cancer.

INTRODUCTION: The growing burden of an aging population has raised concerns about demands on healthcare systems and resources, particularly in the context of surgical and cancer care. Delirium can affect treatment outcomes and patient recovery. We sought to determine the prevalence of postoperative delirium among patients undergoing digestive tract surgery for malignant indications and to analyze the role of delirium on surgical outcomes.

METHODS: Medicare claims data were queried to identify patients diagnosed with esophageal, gastric, hepatobiliary, pancreatic, and colorectal cancers between 2018 and 2021. Postoperative delirium, occurring within 30 days of operation, was identified via International Classification of Diseases, 10th edition codes. Clinical outcomes of interested included "ideal" textbook outcome (TO), characterized as the absence of complications, an extended hospital stay, readmission within 90 days, or mortality within 90 days. Discharge disposition, intensive care unit (ICU) utilization, and expenditures also were examined.

RESULTS: Among 115,654 cancer patients (esophageal: n = 1854, 1.6%; gastric: n = 4690, 4.1%; hepatobiliary: n = 6873, 5.9%; pancreatic: n = 8912, 7.7%; colorectal: n = 93,325, 90.7%), 2831 (2.4%) were diagnosed with delirium within 30 days after surgery. On multivariable analysis, patients with delirium were less likely to achieve TO (OR 0.27 [95% CI 0.25-0.30]). In particular, patients who experienced delirium had higher odds of complications (OR 3.00 [2.76-3.25]), prolonged length of stay (OR 3.46 [3.18-3.76]), 90-day readmission (OR 1.96 [1.81-2.12]), and 90-day mortality (OR 2.78 [2.51-3.08]). Furthermore, patients with delirium had higher ICU utilization (OR 2.85 [2.62-3.11]). Upon discharge, patients with delirium had a decreased likelihood of being sent home (OR 0.40 [0.36-0.46]) and instead were more likely to be transferred to a skilled nursing facility (OR 2.17 [1.94-2.44]). Due to increased utilization of hospital resources, patients with delirium incurred in-hospital expenditures that were 55.4% higher (no delirium: $16,284 vs. delirium: $28,742) and 90-day expenditures that were 100.7% higher (no delirium: $2564 vs. delirium: $8226) (both p < 0.001). Notably, 3-year postoperative survival was adversely affected by delirium (no delirium: 55.5% vs. delirium: 37.3%), even after adjusting risk for confounding factors (HR 1.79 [1.70-1.90]; p < 0.001).

CONCLUSIONS: Postoperative delirium occurred in one in 50 patients undergoing surgical resection of a digestive tract cancer. Delirium was linked to a reduced likelihood of achieving an optimal postoperative outcome, increased ICU utilization, higher expenditures, and a worse long-term prognosis. Initiatives to prevent delirium are vital to improve postoperative outcomes among cancer surgery patients.