title: Neurophysiological assessment of the sedative and analgesic effects of a constant rate infusion of dexmedetomidine in the dog.
abstract: The sedative and analgesic effects of continuous rate infusion (CRI) of dexmedetomidine (DEX) were investigated in Beagle dogs (n=8) using auditory and somatosensory evoked potentials (AEPs and SEPs) recorded before, during and after a CRI of saline or DEX (1.0, 3.0, 5.0 μg/kg bolus, followed by 1.0, 3.0, 5.0 μg/kg/h CRI, respectively). The results showed a significant reduction in AEP at doses of 1.0 μg/kg/h and above and a significant reduction of the SEP at doses of 3.0 and 5.0 μg/kg/h. Neither the AEP nor the SEP was further reduced at 5.0 μg/kg/h when compared to 3.0 μg/kg/h, although a slower return towards baseline values was observed at 5.0 μg/kg/h. The mean plasma levels (±SEM) of DEX during infusion were 0.533±0.053 ng/mL for the 1.0 μg/kg/h dose, 1.869±0.063 ng/mL for the 3.0 μg/kg/h dose and 4.017±0.385 for the 5.0 μg/kg/dose. It was concluded that in adult dogs, a CRI of DEX had a sedative and analgesic effect that could be described quantitatively using neurophysiological parameters. Sedation was achieved at lower plasma levels than required for analgesia, and DEX had a longer (but not larger) effect with infusion rates above 3.0 μg/kg/h.
authors.affiliation: Department of Clinical Sciences of Companion Animals, Division Anaesthesiology and Neurophysiology, Faculty of Veterinary Medicine, Utrecht University, P.O. Box 80.154, Yalelaan 108, NL-3584 CM Utrecht, The Netherlands. h.vanoostrom@uu.nl
authors.forename: Hugo
authors.initials: H
authors.lastname: van Oostrom
authors.forename: Arie
authors.initials: A
authors.lastname: Doornenbal
authors.forename: Arend
authors.initials: A
authors.lastname: Schot
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Stienen
authors.forename: Ludo J
authors.initials: LJ
authors.lastname: Hellebrekers
mesh_terms: D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D000818:Animals; D020927:Dexmedetomidine / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005072:Evoked Potentials, Auditory / Q000187:drug effects*; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects*; D005260:Female; D008297:Male
chemical_list: D018712:Analgesics, Non-Narcotic; D020927:Dexmedetomidine