High serum cortisol level is associated with increased risk of delirium after coronary artery bypass graft surgery: a prospective cohort study

Abstract

IntroductionThe pathophysiology of postoperative delirium remains poorly understood. The purpose of this study was to examine the relationship between serum cortisol level and occurrence of early postoperative delirium in patients undergoing coronary artery bypass graft (CABG) surgery.MethodsA total of 243 patients undergoing elective CABG surgery were enrolled. Patients were examined twice daily during the first five postoperative days and postoperative delirium was diagnosed by using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). Blood samples were obtained between 7 a.m. and 8 a.m. on the first postoperative day and serum cortisol concentrations were then measured. Multivariate logistic regression analyses were performed to identify risk factors of postoperative delirium.ResultsPostoperative delirium occurred in 50.6% (123 of 243) of patients. High serum cortisol level was significantly associated with increased risk of postoperative delirium (OR 3.091, 95% CI 1.763-5.418, P < 0.001). Other independent risk factors of postoperative delirium included increasing age (OR 1.111, 95% CI 1.065-1.159, P < 0.001), history of diabetes mellitus (OR 1.905, 95% CI 1.001-3.622, P = 0.049), prolonged duration of surgery (OR 1.360, 95% CI 1.010-1.831, P = 0.043), and occurrence of complications within the first day after surgery (OR 2.485, 95% CI 1.184-5.214, P = 0.016). Patients who developed postoperative delirium had a higher incidence of postoperative complications and a prolonged duration of postoperative ICU and hospital stay.ConclusionsDelirium was a common complication after CABG surgery. High serum cortisol level was associated with increased risk of postoperative delirium. Patients who developed delirium had outcomes worse than those who did not.

Outcomes Associated With Postoperative Delirium After Cardiac Surgery

“…Like other researchers, 10,11 we found that patients with postoperative delirium generally were older and had more comorbid conditions than did patients without delirium. Additionally, certain factors associated with cardiac surgery procedures and outcomes were also associated with the development of postoperative delirium, including length of surgery time and time on cardiopulmonary bypass.…”

“…Previous studies 11,17 also indicated that patients with postoperative delirium have longer hospital stays. Additionally, because of the increased likelihood of impaired functionality in patients with postoperative delirium, patients with this complication are more likely than patients without delirium to be discharged to a skilled nursing facility, or, if discharged home, are more likely to need home health assistance.…”

“…Limited studies 11,17,18 in cardiac surgery patients have indicated similar outcomes, including higher risks for postoperative complications, prolonged duration of intensive care unit and hospital stay, increased number of readmissions, poorer cognitive and functional outcomes, and higher mortality rates. The purpose of this study was to examine the effect of postoperative delirium on 5 outcome measures in patients who had cardiovascular surgery with use of cardiopulmonary bypass: length of postoperative hospital stay, prevalence of falls, discharge to a nursing facility (skilled nursing facility, long-term acute care facility, rehabilitation center), discharge to home with home health services, and use of inpatient physical therapy.…”

“…Numerous risk factors are associated with the development of postoperative delirium in cardiac surgery patients, including advanced age, high serum levels of cortisol, history of diabetes, use of perioperative analgesics and benzodiazepines, use of cardiac medications (eg, b-blockers, antiarrhythmics, antihypertensives, angiotensin-converting enzyme inhibitors, and calcium channel blockers), and antiemetics given during the postoperative period. 6,[10][11][12] Aspects of cardiac surgery associated with postoperative delirium include increased intubation time, increased surgery time, and the development of surgical complications.…”

Dexmedetomidine for prevention of delirium in elderly patients after non-cardiac surgery: a randomised, double-blind, placebo-controlled trial

“…21,22 Twice daily (in the morning from 0800 h to 1000 h and in the evening from 1800 h to 2000 h) until the seventh day after surgery, we assessed delirium by the Confusion Assessment Method for the ICU (CAM-ICU); (appendix), 23 which has been validated in Chinese patients in the ICU setting 24 and the feasibility of which had been established in our other studies. 25,26 CAM-ICU addresses the four features of delirium, namely, acute onset of mental status changes or a fl uctuating course, inattention, disorganised thinking, and altered level of consciousness. To achieve the diagnosis of delirium, a patient had to display acute onset of mental status changes or fl uctuating course and inattention, with either disorganised thinking or altered level of consciousness.…”