Cerebral protection during open-heart surgery.

To reduce the incidence of cerebral damage after open-heart surgery measures were undertaken based on physiological principles and consideration of the possible injury caused by microemboli. Intellectual function was measured by psychometric tests before and after operation. The results were compared with those of an earlier series. There was a striking reduction in the incidence of neurolocial complications. There was also a considerable reduction in the degree of impairment of intellectual function previously shown to develop after open-heart surgery. However, there are still signs that cardiopulmonary bypass brings about subclinical cerebral injuriies. The measures taken and their rationale are discussed. Psychometric testing is a useful method for evaluating the quality of cardiopulmonary bypass as it allows a quantitative assessment of postoperative cerebral function.