Effect of fentanyl, with or without treatment of bradycardia, on the minimum alveolar concentration of isoflurane and cardiovascular function in dogs.
Vet Anaesth Analg
; 49(1): 26-35, 2022 Jan.
Article
em En
| MEDLINE
| ID: mdl-34654643
ABSTRACT
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. STUDYDESIGN:
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.Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Anestésicos Inalatórios
/
Doenças do Cão
/
Isoflurano
Tipo de estudo:
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Animals
Idioma:
En
Revista:
Vet Anaesth Analg
Assunto da revista:
ANESTESIOLOGIA
/
MEDICINA VETERINARIA
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Estados Unidos