Early versus late extubation after coronary artery bypass grafting: Effects on cognitive function

Objective: To compare the effects of a short period of mechanical ventilation and sedation and a longer one on cognitive functioning of patients exposed to cardiopulmonary bypass (CPB). Design: A randomized, prospective study. Setting: Tertiary-care university hospital. Participants: Forty-eight adult patients with surgical coronary artery disease. Intervention: Elective coronary artery bypass surgery. Measurement and Main Results: Patients (n = 48; mean age, 60.12 +/- 9.30 years) were randomized to either group I (mean delay, 3.49 +/- 2.21 hours) or group II (mean delay, 10.32 +/- 1.75 hours). Cognitive functioning was evaluated before surgery, postoperatively, and at the 8-week follow-up. Tests included measures of central nervous system integrity, attention/concentration and psychomotor performance, verbal fluency, visual scanning speed, mental flexibility, auditory and visual attention, and verbal memory. Covariance analyses were used for group comparisons. Covariates were age, education, and baseline or postoperative performance. No differences in cognitive functioning were found between the two groups. Globally, performance deteriorated for 34.1% of the patients at the posttest evaluation, whereas 2.3% improved and 63.6% remained unchanged. At follow-up, nearly 40.5% of the patients showed an improvement from baseline, 2.4% still had deficits, and 57.1% had no change. None of the cognitive functions appeared to be more affected than others. Conclusion: Early extubation and a shortened period of anesthesia/analgesia do not appear to positively or negatively affect cognitive functioning at 3 to 5 days and 8 weeks postoperatively. Early extubation is suggested because it has no deleterious effect (besides the low risk for reintubation) and it may facilitate patients' care in the intensive care unit. Copyright (C) 1999 by W.B. Saunders Company.