Are preoperative depressive symptoms associated with postoperative delirium in geriatric surgical patients?

Delirium is common in older surgical patients and predicts negative health outcomes. Whether depressive symptoms are prevalent and predict the development of postoperative delirium in elderly surgical patients has not been investigated. Our study aimed to examine the prevalence and prognostic importance of preoperative depressive symptoms in older surgical patients.

Patients at least 65 years of age who were scheduled for major noncardiac surgery were recruited. Preoperatively, patients were screened for symptoms of depression using the 15-point Geriatric Depression Scale (GDS). Postoperative delirium was measured using the Confusion Assessment Method. The associations between covariates and preoperative depression, and postoperative delirium were determined by multivariate logistic regression.

In the 219 patients studied, the mean age was 73.6 +/- 6 years, 12% of patients reported six or more depressive symptoms, and 32% reported three to five depressive symptoms. By multivariate logistic regression, patient characteristics associated with six or more symptoms of depression included <12 years of education, moderate to severe limitation in functional status, and drinking more than two alcoholic beverages per day. Postoperatively, 46% of patients developed delirium. Patients with a greater number of preoperative depressive symptoms were more likely to develop postoperative delirium (p =.048) and experience a longer duration of postoperative delirium (p =.027). Even after adjusting for covariates associated with depression and postoperative delirium--including age, educational level, functional status, and preoperative alcohol use--patients with more than six preoperative depressive symptoms were still significantly more likely to have a longer duration of postoperative delirium than did those patients with fewer than two depressive symptoms (odds ratio = 2.69, confidence interval = 1.04-6.93).

Preoperative screening for the presence of depressive symptoms can be performed easily in elderly patients, and yields useful prognostic information relating to postoperative delirium.