A randomized study of neuropsychological function in patients undergoing coronary bypass surgery.
Fifty-four male patients were examined by an extensive battery of neuropsychological tests before and 1 and 6 months after coronary artery surgery. The patients were randomized to one of three methods of extracorporeal circulation (ECC): bubble oxygenation without an arterial line filter (Group I, n = 17), bubble oxygenation with an arterial filter (Group II, n = 17), or membrane oxygenation without an arterial filter (Group III, n = 20). The mean age was 59 (range 44-69) years. At 1 month nine patients (17%) and at 6 months four patients (7%) had neuropsychological deficits (reduction of 1 standard deviation in two or more 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 15% and 5%, respectively. The differences between groups were not statistically significant. Significantly more patients in the membrane oxygenator group than in the bubble-oxygenator group without a filter performed better in the test for attention, visual scanning, and psychomotor speed and in the test for learning and memory at 1-month follow-up. In conclusion, there exists a risk of neuropsychological dysfunction after ECC, with improvement within the first 6 months, which is independent of the type of oxygenation and the use of arterial line filtration during ECC in this low-risk group.
Sellman
M
M
Department of Thoracic Surgery, Karolinska Institute, Stockholm, Sweden.
Holm
L
L
Ivert
T
T
Semb
B K
BK
D000328:Adult; D000368:Aged; D001026:Coronary Artery Bypass / Q000379:methods*; D005112:Extracorporeal Circulation / Q000009:adverse effects* / Q000379:methods* / Q000523:psychology; D015199:Extracorporeal Membrane Oxygenation / Q000009:adverse effects / Q000523:psychology; D006801:Humans; D007858:Learning; D008297:Male; D008568:Memory; D008875:Middle Aged; D009483:Neuropsychological Tests; D011597:Psychomotor Performance