Cerebral blood flow and metabolism during cardiopulmonary bypass with special reference to effects of hypotension induced by XXXX .

@entity1 @entity101 @entity26 @entity4770 @entity880 @entity544 @entity413 @entity2332
Cerebral blood flow and metabolism of @entity26 , @entity413 , and @entity880 were studied in 43 @entity1 undergoing aortocoronary bypass. Twenty-five @entity1 received @entity4770 infusion, 50 ng per kilogram of body weight per minute, during cardiopulmonary bypass (CPB), and 18 @entity1 served as a control group. Regional cerebral blood flow (CBF) was studied by intraarterially injected xenon 133 and a single scintillation detector. @entity26 tension, @entity544 tension, @entity26 saturation, @entity413 , and @entity880 were measured in arterial and cerebral venous blood. Mean arterial blood pressure decreased during @entity2332 and @entity4770 infusion to less than 30 mm Hg. The regional CBF was, on average, 22 (standard deviation [SD] 4) ml/100 gm/min before CPB. It increased in the control group during @entity2332 to 34 (SD 12) ml/100 gm/min, but decreased in the @entity4770 group to 15 (SD 5) ml/100 gm/min. It increased during rewarming in the @entity4770 group. After CPB, regional CBF was about 40 ml/100 gm/min in both groups. The cerebral arteriovenous @entity26 pressure difference decreased more in the control group than in the @entity4770 group during @entity2332 . The cerebral metabolic rate of @entity26 decreased in both groups from approximately 2 ml/100 gm/min to about 1 ml/100 gm/min during @entity2332 , @entity101 during rewarming, and after CPB was at the levels measured before bypass in both groups. There was no difference between the groups in regard to @entity413 and @entity880 metabolism.
