Predictors and outcomes of delirium

To determine factors associated with the occurrence of delirium among patients undergoing surgical repair of abdominal aortic aneurysm (AAA).

The sample included all consenting patients who underwent AAA repair during a 12-month period. Before surgery, daily while in hospital, and at 1 and 6 months after surgery, we assessed patients' mood, mental status and functional status. We compared delirious and nondelirious patients for severity of preoperative depressive symptoms, length of hospital stay and mortality. The effects of delirium on postoperative functional status were assessed in conjunction with postoperative depressive symptoms using regression models.

The sample of 35 patients was primarily male and elderly; one-quarter had three or more medical conditions; and eight (23%) developed delirium after surgery. Postoperative delirium was significantly associated with preoperative depressive symptoms, alcohol use and cognitive impairment as well as with longer lengths of stay and poorer functional status at 1 and 6 months after surgery.

Identification and treatment of patients with depressive symptoms, alcohol use and cognitive impairment prior to AAA surgery could reduce the incidence of postoperative delirium and the prolonged hospital stays and impaired functional status associated with it. Surgeons should consider using simple screening instruments before surgery to identify patients at risk and referring them for psychiatric evaluation and treatment. They should also consider including psychiatrists early in the care of high-risk patients to improve detection of and early intervention for delirium.