Pressure-dependent cerebral ischemia during cardiopulmonary bypass

In terms of the three purposes set forth at the beginning of this paper, the findings of the present study indicate that: (1) extracorporeal perfusion at pressures below SO torr can result in ischemic brain damage and postoperative central nervous system dysfuncton; (2) the risk of these complications is roughly proportional to the depth and duration of the hypotension but also varies with the extent of cerebral atherosclerosis and the age of the patient; and (3) the deliberate use of pressor agents to prevent mean arterial pressure from falling below 50 torr can reduce CNS morbidity and mortality after cardiopulmonary bypass, although higher minimum pressures are probably desirable.