Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA.
Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA; Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California Davis, Davis, CA, USA.
Vet Anaesth Analg. 2022 Jan;49(1):26-35. doi: 10.1016/j.vaa.2021.09.001. Epub 2021 Sep 20.
To determine the effect of fentanyl on the minimum alveolar concentration of isoflurane (MAC) and cardiovascular variables in dogs, and how the treatment of bradycardia affects them.
Prospective, randomized crossover-controlled trial.
A total of six male Beagle dogs weighing 9.9 ± 0.7 kg (mean ± standard deviation) and aged 13 months.
To each dog, two treatments were assigned on different days: fentanyl (FENTA) or fentanyl plus glycopyrrolate (FENTA) to maintain heart rate (HR) between 100 and 132 beats minute. Determinations of MAC were performed with 10 plasma fentanyl target concentrations ([Fenta] (0, 0.16, 0.32, 0.64, 1.25, 2.5, 5.0, 10.0, 20.0 and 40.0 ng mL) for FENTA and 5 [Fenta] (0, 1.25, 2.5, 5.0, 10.0 ng mL)) for FENTA. During each MAC 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 MAC 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.
Fentanyl decreased MAC 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 (typical values of population model), respectively. The prevention of fentanyl-mediated bradycardia caused no significant effect on MAC, but increased HR, MAP and CI, and decreased SVRI when compared with isoflurane alone.
Fentanyl caused a plasma concentration-dependent decrease in MAC, 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.
确定芬太尼对异氟醚最小肺泡浓度（MAC）和犬心血管变量的影响，以及治疗心动过缓如何影响这些变量。
前瞻性、随机交叉对照试验。
共 6 只雄性比格犬，体重 9.9 ± 0.7 kg（平均值 ± 标准差），年龄 13 个月。
对每只狗在不同天分配两种处理：芬太尼（FENTA）或芬太尼加格隆溴铵（FENTA）以维持心率（HR）在 100-132 次/分钟之间。使用 10 种不同的血浆芬太尼靶浓度[Fenta]（0、0.16、0.32、0.64、1.25、2.5、5.0、10.0、20.0 和 40.0 ng/ml）进行 FENTA 测定，以及 5 种[Fenta]（0、1.25、2.5、5.0 和 10.0 ng/ml）进行 FENTA。在每次 MAC 测定期间，测量心血管变量[平均动脉压（MAP）、HR 和心指数（CI）]，并计算全身血管阻力指数（SVRI）。使用药效动力学模型描述芬太尼对 MAC 和心血管变量的影响的血浆芬太尼浓度[Fenta]-反应关系。采用混合模型方差分析，随后采用 Dunnett 或 Tukey 检验，以及 Bonferroni 调整分别用于各处理内和各处理间的比较。显著性设定为 p<0.05。
芬太尼最大程度地降低了 84%的 MAC。产生 50%MAC、HR 和 CI 降低的[Fenta]浓度分别为 2.64、3.65 和 4.30 ng/ml（人群模型的典型值）。与单独使用异氟醚相比，预防芬太尼介导的心动过缓对 MAC 没有显著影响，但增加了 HR、MAP 和 CI，并降低了 SVRI。
芬太尼引起了与血浆浓度相关的 MAC、HR 和 CI 的降低，以及 SVRI 的增加。在异氟醚麻醉的犬中，与芬太尼相关的心血管改善仅在预防芬太尼介导的心动过缓时发生。
