Postoperative Delirium and Short-term Cognitive Dysfunction Occur More Frequently in Patients Undergoing Valve Surgery With or Without Coronary Artery Bypass Graft Surgery Compared With Coronary Artery Bypass Graft Surgery Alone: Results of a Pilot Study
published online 23 July 2010. Corrected Proof
Objective
The authors tested the hypothesis that patients undergoing valve repair or replacement surgery with or without coronary artery bypass graft (CABG) surgery using cardiopulmonary bypass (CPB) had a greater incidence of postoperative delirium and cognitive dysfunction compared with patients undergoing CABG surgery alone.
Design
Prospective study.
Setting
Veterans Affairs medical center.
Participants
Forty-four age- and education-balanced male patients (≥55 years of age) undergoing elective cardiac surgery with CPB (n = 22 valve ± CABG surgery and n = 22 CABG surgery alone) and nonsurgical controls (n = 22) were recruited.
Interventions
None.
Measurements and Main Results
Delirium was assessed with the Intensive Care Delirium Screening Checklist before and for 5 consecutive days after surgery. Recent verbal and nonverbal memory and executive functions were assessed using a psychometric test battery before and 1 week after cardiac surgery or at 1-week intervals in nonsurgical controls. Intensive care unit stay, hospital stay, and 30-day readmission were significantly (p = 0.03, p = 0.01, and p = 0.04, respectively) longer in patients undergoing valve surgery ± CABG surgery versus CABG surgery alone. Postoperative delirium occurred more frequently (p = 0.01) in patients undergoing valve ± CABG surgery versus CABG surgery alone. Overall cognitive performance (composite z score) after surgery also was impaired significantly (p = 0.004) in patients undergoing valve ± CABG surgery compared with CABG surgery alone. The composite z score after surgery decreased by at least 1.5 standard deviations in 11 patients (50%) versus 1 patient (5%) without valve surgery compared with nonsurgical controls (p = 0.001, Fisher's exact test). The presence of delirium predicted a composite z score decrease of 1.2 points (odds ratio = 0.30; 95% confidence interval, 0.13-0.68).
Conclusions
The results indicated that patients undergoing valve surgery with or without CABG surgery have a higher incidence of postoperative delirium and cognitive dysfunction 1 week after surgery compared with those undergoing CABG surgery alone.
Department of Anesthesiology, Medical College of Wisconsin and Clement J. Zablocki Veterans Administration Medical Center, Milwaukee, WI
Address reprint requests to Judith A. Hudetz, PhD, Department of Anesthesiology, Clement J. Zablocki Veterans Administration Medical Center, 5000 W National Avenue, Milwaukee, WI 53295
Supported in part by the Medical College of Wisconsin Institutional Grant #9304795.
ABSTRACT