Abstract
BACKGROUND: The population is aging rapidly, and the population of patients who undergo surgeries is aging, too. Elderly patients have much risk of postoperative delirium, which increases the number of adverse events. The aim of this study was to investigate the risk factors of postoperative delirium in elderly patients with colorectal cancer. METHODS: We conducted a retrospective cohort analysis of consecutive patients aged 70 years and older who underwent surgeries for colorectal cancer at our department in the period from May 2012 to October 2019. We investigated the correlation between the incidence of postoperative delirium and Comprehensive Geriatric Assessment (CGA) scores, comorbidities, and perioperative factors. Postoperative delirium was retrospectively diagnosed by checking clinical records. RESULTS: Postoperative delirium was diagnosed in 36 of 271 patients (13.3%) with colorectal cancer. Among many comorbidities, only renal disease was significantly associated with postoperative delirium. Among the items in the CGA, age; Mini-Mental State Exam (MMSE), Barthel Index, Instrumental Activities of Daily Living (IADL), Vitality Index, and Geriatric Depression Scale (GDS) scores; and grip strength were associated with postoperative delirium. Among perioperative factors, blood transfusion was associated with postoperative delirium. Multivariate logistic regression analysis identified older age, MMSE, GDS, and grip strength as significant independent risk factors for postoperative delirium. CONCLUSIONS: This single-center retrospective observational study demonstrated that grip strength is an independent predictor of postoperative delirium, along with age, MMSE, and GDS.