Cerebral surveillance during cardiac surgery.

There is at present no ideal method for determining the adequacy of cerebral blood flow during nonpulsatile cardiopulmonary bypass procedures. Clinical evaluation of cerebral function while the patient is under general anesthesia may be misleading and unsuspected cerebral damage could result if perfusion of the cerebrovascular bed is inadequate. Electroencephalography appears to be the only reliable noninvasive means of cerebral surveillance during the critical periods of nonpulsatile perfusion.