title: Effect of dexmedetomidine, a selective and potent alpha 2-agonist, on cerebral blood flow and oxygen consumption during halothane anesthesia in dogs.
abstract: The effect of the alpha 2-agonist dexmedetomidine on the cerebral blood flow (CBF) and the metabolic rate for oxygen was studied by a sagittal sinus outflow technique in dogs during halothane anesthesia. Dexmedetomidine was given in a dose (10 micrograms/kg) reported to reduce the anesthetic requirement of halothane by 90%. During 0.9% halothane anesthesia dexmedetomidine caused a significant reduction in CBF without influencing the metabolic rate for oxygen. Reducing the halothane concentration to 0.1% caused no further change in CBF, but increased the metabolic rate for oxygen 19%. The cerebral vasoconstrictive effect, combined with the 90% reduction in MAC for halothane, indicates that dexmedetomidine might be a useful adjunct to inhalation anesthetics during neurosurgery in situations where an increase in CBF should be avoided.
authors.affiliation: Institute for Experimental Medical Research, University of Oslo, Norway.
authors.forename: B R
authors.initials: BR
authors.lastname: Karlsson
authors.forename: M
authors.initials: M
authors.lastname: Forsman
authors.forename: O K
authors.initials: OK
authors.lastname: Roald
authors.forename: M S
authors.initials: MS
authors.lastname: Heier
authors.forename: P A
authors.initials: PA
authors.lastname: Steen
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000769:Anesthesia, Inhalation; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002245:Carbon Dioxide / Q000097:blood; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D004285:Dogs; D004569:Electroencephalography / Q000187:drug effects; D005260:Female; D006221:Halothane / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000494:pharmacology*; D008297:Male; D020926:Medetomidine; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption / Q000187:drug effects*
chemical_list: D000316:Adrenergic alpha-Agonists; D007093:Imidazoles; D002245:Carbon Dioxide; D020926:Medetomidine; D010100:Oxygen; D006221:Halothane