title: The anesthetic interaction of propofol and sevoflurane on the minimum alveolar concentration preventing motor movement (MACNM) in dogs.
abstract: The objective of this study was to determine the effects of propofol on the minimum alveolar concentration of sevoflurane needed to prevent motor movement (MAC(NM)) in dogs subjected to a noxious stimulus using randomized crossover design. Six, healthy, adult beagles (9.2 ± 1.3 kg) were used. Dogs were anesthetized with sevoflurane on 3 occasions, at weekly intervals, and baseline MAC(NM) (MAC(NM-B)) was determined on each occasion. Propofol treatments were administered as loading dose (LD) and constant rate infusion (CRI) as follows: Treatment 1 (T1) was 2 mg/kg body weight (BW) and 4.5 mg/kg BW per hour; T2 was 4 mg/kg BW and 9 mg/kg BW per hour; T3 was 8 mg/kg BW and 18 mg/kg BW per hour, respectively. Treatment MAC(NM) (MAC(NM-T)) determination was initiated 60 min after the start of the CRI. Two venous blood samples were collected and combined at each MAC(NM-T) determination for measurement of blood propofol concentration using high-performance liquid chromatography method (HPLC). Data were analyzed using a mixed-model ANOVA and are presented as least square means (LSM) ± standard error of means (SEM). Propofol infusions in the range of 4.5 to 18 mg/kg BW per hour resulted in mean blood concentrations between 1.3 and 4.4 μg/mL, and decreased (P < 0.05) sevoflurane MAC(NM) in a concentration-dependent manner. The percentage decrease in MAC(NM) was 20.5%, 43.0%, and 68.3%, with corresponding blood propofol concentrations of 1.3 ± 0.3 μg/mL, 2.5 ± 0.3 μg/mL, and 4.4 ± 0.3 μg/mL, for T1, T2, and T3, respectively. Venous blood propofol concentrations were strongly correlated (r = 0.855, P < 0.0001) with the decrease in MAC(NM). In dogs, propofol decreased the sevoflurane MAC(NM) in a concentration-dependent manner.
authors: Department of Small Animal Clinical Sciences (Singsank-Coats, Egger); Department of Large Animal Clinical Sciences (Seddighi, Doherty); and Department of Biological and Diagnostic Sciences (Rohrbach, Cox), College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee, USA.
authors: Jill
authors: J
authors: Singsank-Coats
authors: Department of Small Animal Clinical Sciences (Singsank-Coats, Egger); Department of Large Animal Clinical Sciences (Seddighi, Doherty); and Department of Biological and Diagnostic Sciences (Rohrbach, Cox), College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee, USA.
authors: Reza
authors: R
authors: Seddighi
authors: Department of Small Animal Clinical Sciences (Singsank-Coats, Egger); Department of Large Animal Clinical Sciences (Seddighi, Doherty); and Department of Biological and Diagnostic Sciences (Rohrbach, Cox), College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee, USA.
authors: Barton W
authors: BW
authors: Rohrbach
authors: Department of Small Animal Clinical Sciences (Singsank-Coats, Egger); Department of Large Animal Clinical Sciences (Seddighi, Doherty); and Department of Biological and Diagnostic Sciences (Rohrbach, Cox), College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee, USA.
authors: Sherry K
authors: SK
authors: Cox
authors: Department of Small Animal Clinical Sciences (Singsank-Coats, Egger); Department of Large Animal Clinical Sciences (Seddighi, Doherty); and Department of Biological and Diagnostic Sciences (Rohrbach, Cox), College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee, USA.
authors: Christine M
authors: CM
authors: Egger
authors: Department of Small Animal Clinical Sciences (Singsank-Coats, Egger); Department of Large Animal Clinical Sciences (Seddighi, Doherty); and Department of Biological and Diagnostic Sciences (Rohrbach, Cox), College of Veterinary Medicine, University of Tennessee, Knoxville, Tennessee, USA.
authors: Thomas J
authors: TJ
authors: Doherty
mesh_terms: D019162:Anesthetics, Combined / Q000494:pharmacology*; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000494:pharmacology*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D018592:Cross-Over Studies; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005260:Female; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects*; D015742:Propofol / Q000008:administration & dosage / Q000494:pharmacology*; D011650:Pulmonary Alveoli; D000077149:Sevoflurane
chemical_list: D019162:Anesthetics, Combined; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D008738:Methyl Ethers; D000077149:Sevoflurane; D015742:Propofol