Acidemia impairs autoregulation of cerebral blood flow in newborn XXXX .

@entity1 @entity932 @entity742 @entity520 @entity2647 @entity880 @entity209
Cerebral blood flow (CBF) and autoregulation of cerebral blood flow were assessed in newborn @entity742 before and after inducing @entity209 . CBF was measured by xenon washout and autoregulation by the change in CBF after increasing mean arterial pressure (MAP) 30 per cent with 0.02 per cent @entity2647 . After surgical preparation, stabilization, and demonstration of the presence of autoregulation, six @entity742 received 10 mg X kg-1 of @entity880 intravenously over 30 minutes. Arterial pH decreased from 7.35 +/- 0.01 (mean +/- SEM) during the control period to 6.96 +/- 0.02 (p less than 0.01) at the end of the @entity880 infusion. Arterial blood gases, MAP's, and heart rates did not change. Prior to @entity880 infusion, CBF before and after raising MAP were 53 +/- 3 ml/100 g/min and 56 +/- 4 ml/100 g/min respectively. After @entity880 infusion, CBF increased from 54 +/- 2 ml/100 g/min to 62 +/- 3 ml/100 g/min (p less than 0.05) following @entity2647 induced rise in MAP. Five control @entity742 showed no significant change in any of these variables, including CBF, over the same time periods. These data indicate that @entity520 per se does not alter CBF, but that @entity520 impairs cerebral vascular autoregulation in hyperoxic @entity742 . Similar changes in @entity1 neonates might result in @entity932 .
