Head and Heart: Neuropsychological Reaction and Arterial Line Filtration during Cardiopulmonary Bypass

Abstract

As part of a prospective study of neuropsychologic reactions after cardiopulmonary bypass and their relation to arterial line filters, 44 patients who underwent elective cardiac operations were randomized into two groups. Group A had a 40-micron nylon screen filter in the arterial line. No arterial filter was used in group B. Neuropsychological examinations of all patients were conducted before and at a mean of 8 days after the operation on a double blind basis by a single trained psychologist. The tests included the Wechsler Memory Scale, the trail-making test, the Hamilton Anxiety Rating Scale, and the Hamilton Rating Scale for Depression. The 2 groups were otherwise similar with respect to preoperative neurologic and intellectual status, anesthetic methods, duration of operation, operative procedures performed, and the time spent in the intensive care unit. Surprisingly, there was a highly significant improvement in all four test scores after surgery. There were no statistically significant differences in the test scores between the two groups but considerable inter-patient performance variability was noted. The arterial line filter did not appear to have an effect on test scores. Routine use of an arterial filter remains questionable.