The effect of phenobarbital on cerebral blood flow in newborn infants with foetal distress.

The effect of phenobarbital on cerebral blood flow (CBF) was investigated by the intravenous Xenon133 clearance technique in seven term newborn infants with signs of mild to moderate hypoxic ischaemic encephalopathy, all on sustained spontaneous ventilation. Phenobarbital treatment had no significant effect on CBF 60 min after loading dosage (20 mg/kg i.v.). Likewise, no significant change in mean arterial blood pressure, heart rate or transcutaneous gas tensions was observed. Though slight changes in CBF of short duration cannot be excluded, conventional dosage of phenobarbital to term newborn infants with foetal distress apparently imposes no risk of cerebrovascular damage.