Cerebral damage following open-heart surgery in deep hypothermia and circulatory arrest.

Six patients undergoing aortic arch replacement during deep hypothermia and circulatory arrest were subjected to studies including serial determinations of total creatine kinase (CK) activity in the cerebrospinal fluid (CSF), monitoring of the intracranial epidural pressure and the cerebral perfusion pressure and clinical neurological evaluation. In two of four patients with postoperative pressure monitoring, a marked increase in pressure was seen. In one case this pressure rise terminated in brain tamponade six days postoperatively, despite aggressive treatment with steroids, mannitol and barbiturate. In comparison with patients undergoing surgery for valve replacement or aorto-coronary by-pass, some of the patients with aortic arch replacement clearly sustained more severe cerebral damage, as judged by clinical examination and autopsy findings as well as by assessment of the degree or extent of the neuronal damage from CK activity in CSF. Patients of this type are obvious candidates for postoperative neuro-intensive monitoring and care. Repeated pulsed Doppler flow velocity determinations in precerebral arteries, performed bedside, combined with monitoring of the cerebral perfusion pressure, provide a useful indication of the cerebral circulatory state in such situations.