A RANDOMIZED STUDY OF NEUROPSYCHOLOGICAL FUNCTION IN PATIENTS UNDERGOING CORONARY-BYPASS SURGERY

Fifty-four male patients were examined by an extensive battery of neur opsychological tests before and 1 and 6 months after coronary artery s urgery. The patients were randomized to one of three methods of extrac orporeal circulation (ECC): bubble oxygenation without an arterial lin e filter (Group I, n = 17), bubbel oxygenation with an arterial filter (Group II, n = 17), or membrane oxygenation without an arterial filte r (Group III, n= 20). The mean age was 59 (range 44-69) years. At 1 mo nth nine patients (17 %) and at 6 months four patients (7 %) had neuro psychological deficits (reduction of 1 standard deviation in two or mo re tests). Postoperative intellectual dysfunction was found in groups I, II, and III at 1 and 6 months in 24 % and 12 %, 12 % and 6 %, and 1 5 % and 5 %, respectively. The differences between groups were not sta tistically significant. Significantly more patients in the membrane ox ygenator group than in the bubble-oxygenator group without a filter pe rformed better in the test for attention, visual scanning, and psychom otor speed and in the test for learning and memory at 1-month follow-u p. In conclusion, there exists a risk of neuropsychological dysfunctio n after ECC, with improvement within the first 6 months, which is inde pendent of the type of oxygenation and the use of arterial line filtra tion during ECC in this low-risk group.