Neuropsychological disorders after coronary bypass surgery.

OBJECTIVES A prospective assessment of neuropsychological impairment in the early postoperative stage after coronary bypass surgery. METHODS Seventy patients undergoing elective coronary bypass surgery (CABG) were investigated preoperatively, two to three and five to nine days postoperatively with a comprehensive neuropsychological assessment including orientation, word fluency, naming, arithmetic, memory, and visuoconstructive tasks. RESULTS Patients exhibited significant early postoperative impairment affecting all tasks but naming. Except for the orientation measurement, most patients recovered by the fifth to ninth postoperative day. Only six patients had delirium according to DSM III-R criteria on the second or third postoperative day. Cluster analysis of neuropsychological data obtained on the second to third postoperative day identified 10 patients who were cognitively compromised. As a group, these patients had required a greater number of defibrillations and exhibited lower cardiac indices postoperatively. Preoperatively, patients at risk for postoperative dysfunction were characterised by lower verbal memory, word fluency, and clock orientation scores. CONCLUSIONS Simple preoperative neuropsychological assessment may be helpful and clinically applicable in identifying patients at risk for postoperative cognitive dysfunction and may contribute to improve postoperative management aiming at the prevention of delirium or other transient neuropsychological disorders.