TY - JOUR
T1 - Effect of fentanyl, with or without treatment of bradycardia, on the minimum alveolar concentration of isoflurane and cardiovascular function in dogs
AU - Machado, Marcela L.
AU - Soares, Joao H.N.
AU - Pypendop, Bruno H.
AU - Henao-Guerrero, Natalia
AU - Oliveira, Renato L.S.
N1 - Funding Information:
The authors thank the staff personnel from the Teaching and Research Animal Care Support Service of Virginia?Maryland College of Veterinary Medicine and Dr John H Rossmeisl for their valuable technical assistance. This work was supported by discretionary funds from the Department of Small Animal Clinical Sciences of Virginia?Maryland College of Veterinary Medicine, Virginia Tech (JHNS and NHG) and from the Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California Davis (BHP). This study was presented in part at the 13th World Congress of Veterinary Anesthesiology, September 2018, Venice, Italy.
Funding Information:
The authors thank the staff personnel from the Teaching and Research Animal Care Support Service of Virginia–Maryland College of Veterinary Medicine and Dr John H Rossmeisl for their valuable technical assistance. This work was supported by discretionary funds from the Department of Small Animal Clinical Sciences of Virginia–Maryland College of Veterinary Medicine, Virginia Tech (JHNS and NHG) and from the Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California Davis (BHP). This study was presented in part at the 13th World Congress of Veterinary Anesthesiology, September 2018, Venice, Italy.
Publisher Copyright:
© 2021 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia
PY - 2021
Y1 - 2021
N2 - Objective: To determine the effect of fentanyl on the minimum alveolar concentration of isoflurane (MACISO) and cardiovascular variables in dogs, and how the treatment of bradycardia affects them. Study design: Prospective, randomized crossover-controlled trial. Animals: A total of six male Beagle dogs weighing 9.9 ± 0.7 kg (mean ± standard deviation) and aged 13 months. Methods: To each dog, two treatments were assigned on different days: fentanyl (FENTA) or fentanyl plus glycopyrrolate (FENTAglyco) to maintain heart rate (HR) between 100 and 132 beats minute−1. Determinations of MACISO were performed with 10 plasma fentanyl target concentrations ([Fenta]Target (0, 0.16, 0.32, 0.64, 1.25, 2.5, 5.0, 10.0, 20.0 and 40.0 ng mL−1) for FENTA and 5 [Fenta]Target (0, 1.25, 2.5, 5.0, 10.0 ng mL−1)) for FENTAglyco. During each MACISO determination, cardiovascular variables [mean arterial pressure (MAP), HR and cardiac index (CI)] were measured, and systemic vascular resistance index (SVRI) calculated. Pharmacodynamic models were used to describe the plasma fentanyl concentration [Fenta]–response relationship for the effect on MACISO and cardiovascular variables. A mixed-model analysis of variance followed by Dunnett's or Tukey's test, and the Bonferroni adjustment were used for comparisons within and between each treatment, respectively. Significance was set as p < 0.05. Results: Fentanyl decreased MACISO by a maximum of 84%. The [Fenta] producing 50% decrease in MAC, HR and CI were 2.64, 3.65 and 4.30 ng mL−1 (typical values of population model), respectively. The prevention of fentanyl-mediated bradycardia caused no significant effect on MACISO, but increased HR, MAP and CI, and decreased SVRI when compared with isoflurane alone. Conclusions and clinical relevance: Fentanyl caused a plasma concentration-dependent decrease in MACISO, HR and CI and an increase in SVRI. Cardiovascular improvements associated with fentanyl in isoflurane-anesthetized dogs only occurred when the fentanyl-mediated bradycardia was prevented.
AB - Objective: To determine the effect of fentanyl on the minimum alveolar concentration of isoflurane (MACISO) and cardiovascular variables in dogs, and how the treatment of bradycardia affects them. Study design: Prospective, randomized crossover-controlled trial. Animals: A total of six male Beagle dogs weighing 9.9 ± 0.7 kg (mean ± standard deviation) and aged 13 months. Methods: To each dog, two treatments were assigned on different days: fentanyl (FENTA) or fentanyl plus glycopyrrolate (FENTAglyco) to maintain heart rate (HR) between 100 and 132 beats minute−1. Determinations of MACISO were performed with 10 plasma fentanyl target concentrations ([Fenta]Target (0, 0.16, 0.32, 0.64, 1.25, 2.5, 5.0, 10.0, 20.0 and 40.0 ng mL−1) for FENTA and 5 [Fenta]Target (0, 1.25, 2.5, 5.0, 10.0 ng mL−1)) for FENTAglyco. During each MACISO determination, cardiovascular variables [mean arterial pressure (MAP), HR and cardiac index (CI)] were measured, and systemic vascular resistance index (SVRI) calculated. Pharmacodynamic models were used to describe the plasma fentanyl concentration [Fenta]–response relationship for the effect on MACISO and cardiovascular variables. A mixed-model analysis of variance followed by Dunnett's or Tukey's test, and the Bonferroni adjustment were used for comparisons within and between each treatment, respectively. Significance was set as p < 0.05. Results: Fentanyl decreased MACISO by a maximum of 84%. The [Fenta] producing 50% decrease in MAC, HR and CI were 2.64, 3.65 and 4.30 ng mL−1 (typical values of population model), respectively. The prevention of fentanyl-mediated bradycardia caused no significant effect on MACISO, but increased HR, MAP and CI, and decreased SVRI when compared with isoflurane alone. Conclusions and clinical relevance: Fentanyl caused a plasma concentration-dependent decrease in MACISO, HR and CI and an increase in SVRI. Cardiovascular improvements associated with fentanyl in isoflurane-anesthetized dogs only occurred when the fentanyl-mediated bradycardia was prevented.
KW - cardiovascular
KW - dog
KW - fentanyl
KW - isoflurane
KW - minimum alveolar concentration
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U2 - 10.1016/j.vaa.2021.09.001
DO - 10.1016/j.vaa.2021.09.001
M3 - Article
C2 - 34654643
AN - SCOPUS:85116903623
JO - Veterinary Anaesthesia and Analgesia
JF - Veterinary Anaesthesia and Analgesia
SN - 1467-2987
ER -