Influence of Anesthetic Induction with Halothane and Isoflurane on Internal Carotid Blood Flow Velocity in Early Infancy

Abstract

In contrast to adult humans and animals, so far there are no studies in infancy on the effects of halothane and isoflurane on cerebral hemodynamics. We used transfontanellar Doppler ultrasonography to close this gap. In the study we looked at changes of Vmax as a measure of changes in cerebral blood flow. In 10 infants (4.7 +/- 1.0 kg BW) Vmax decreased 5 min after anesthetic induction with halothane 1.5% at 33%, and in a comparable group of 10 infants (5.3 +/- 1.2 kg BW) 5 min after anesthetic induction with an equipotential dose of isoflurane 2.5% at 28%. In 4 infants there was even a retrograde diastolic flow under anesthetic induction. This decrease was so far never seen in adults, in whom halothane increases cerebral blood flow and isoflurane has only little effect.