Influence of anesthetics on cerebral blood flow velocity in infancy. Effects of halothane versus thiopental-fentanyl.
We studied the effects of 2 anesthetic protocols on blood flow velocity of the middle cerebral artery, measured with a pulsed Doppler sonograph in infants. A first group of 10 infants (mean age 64 days) was anesthetized with halothane and nitrous oxide. A second group of 10 infants (mean age 88 days) was anesthetized with thiopental-fentanyl i.v. and nitrous oxide. Heart rate, mean arterial blood pressure (MABP) and mean velocity (MV) decreased during both types of anesthesia. Decrease of MV was of the same magnitude in the 2 groups but MABP decreased more under halothane. After skin incision MABP and MV increased in both groups but MV followed MABP more closely under halothane than under thiopental. These results suggest cerebral blood flow (CBF) reduction after both inductions but by a different mechanism. In spite of cerebral arteriolar dilation with halothane, CBF decreases by means of severe reduction of MABP: CBF is pressure-passive and autoregulation seems to be impaired. In contrast, thiopental induces cerebral arteriolar constriction but CBF is less dependent of MABP changes.
Messer
J
J
Pédiatrie 2 - Néonatologie, Hôpital de Hautepierre, Centre Hospitalier Universitaire de Strasbourg, France.
Haddad
J
J
Bientz
J
J
Jochum
D
D
D000777:Anesthetics / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D005283:Fentanyl / Q000494:pharmacology*; D006221:Halothane / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007223:Infant; D013514:Surgical Procedures, Operative / Q000009:adverse effects; D013874:Thiopental / Q000494:pharmacology*
D000777:Anesthetics; D013874:Thiopental; D005283:Fentanyl; D006221:Halothane