Background: Coronary artery bypass grafting (CABG) is one of the main methods of treatment of coronary artery disease. Neuropsychological testing is a sensitive method for quantitative assessment of cognitive dysfunctioning following cardiopulmonary bypass. The aim of the present clinical study was to evaluate the neuropsychologic changes in CABG patients, operated with normothermic or hypothermic cardiopulmonary bypass (CPB).
Methods: Neuropsychological changes were assessed in 33 first-time CABG patients before and 3-10 days after surgery. Patients underwent CABG with hypothermic (Gr. H, n = 17) or normothermic (Gr. N, n = 16) CPB with standard anesthesia. Neuropsychological performance was assessed using a well-established battery of 10 tests. A neuropsychological test battery includes: Digit Span-subtest of WAIS-R (PL), the Trail Making Test, Raven Test, Benton, Bourdon, Verbal Fluency (F,A,S), Turm von Hanoi, Rey Auditory Verbal Learning Test, Supermarket, WAIS-R (PL) Digit Symbol-subtest of WAIS-R (PL). All patients completed the test for perception, attention, immediate and delayed verbal and visual memory, visual and verbal learning, problem-solving strategies, abstraction, recognition, word fluency, visual- motor coordination and psychomotor speed. For comparison, the incidence of decline using the 1.5 standard deviation (at least in 2 tests) also was calculated.
Results: Comparing the reliable change and SD methods, statistically significant differences in the incidence of decline were observed in 6 of the 10 neuropsychological measures. Patients' scores showed a significant deterioration in concentration of attention, immediate verbal memory, psychomotor speed, visuoconstructive tasks and verbal learning. Neuropsychological deficits were found in 66.7% of patients after surgery. Post-operative deficits were not associated with the method used (normothermia or hypothermia).