Gibbs N M, Larach D R, Schuler H G
Department of Anesthesia, Pennsylvania State University College of Medicine, Hershey 17033.
Anesthesiology. 1989 Aug;71(2):214-7. doi: 10.1097/00000542-198908000-00009.
The effect of neuromuscular blockade with vecuronium on the hemodynamic responses to a noxious stimulus was investigated in male Sprague-Dawley rats. The rats were anesthetized with either halothane (group 1, n = 10), or isoflurane (group 2, n = 10). The maximum values for heart rate and mean arterial pressure during the noxious stimulus (base-tail clamp) were measured, and the maximum changes in these values (maximum minus prestimulation) were calculated. The responses were measured at two different anesthetic concentrations (0.6 X MAC, 0.75 X MAC), before and after vecuronium 1.0 mg.kg-1 iv. It was found that neuromuscular blockade with vecuronium did not reduce any of the hemodynamic responses measured, at either anesthetic concentration, in either the halothane or the isoflurane group. However, increasing the anesthetic concentration from 0.6 X MAC to 0.75 X MAC produced statistically significant (P less than 0.01) reductions in several of the responses measured. The inability of vecuronium to reduce hemodynamic responses to noxious stimuli in this study suggests that neuromuscular blockade does not alter anesthetic depth in the rat. A knowledge of this "absence of effect" may be important for investigators who need to induce muscle relaxation in laboratory animals prior to examining the effect of anesthetic agents on hemodynamic responses to noxious stimuli. The results also question the ability of neuromuscular blockade to reduce anesthetic requirement, and support the view that neuromuscular blockade does not contribute to the anesthetic state.
在雄性斯普拉格 - 道利大鼠中，研究了维库溴铵所致神经肌肉阻滞对有害刺激引起的血流动力学反应的影响。大鼠分别用氟烷（第1组，n = 10）或异氟烷（第2组，n = 10）麻醉。测量有害刺激（基础 - 尾部钳夹）期间心率和平均动脉压的最大值，并计算这些值的最大变化（最大值减去刺激前值）。在维库溴铵1.0mg·kg-1静脉注射前后，于两种不同麻醉浓度（0.6倍MAC，0.75倍MAC）下测量反应。结果发现，在氟烷组或异氟烷组中，无论哪种麻醉浓度，维库溴铵所致的神经肌肉阻滞均未降低所测量的任何血流动力学反应。然而，将麻醉浓度从0.6倍MAC增加到0.75倍MAC，可使所测量的几种反应出现统计学显著降低（P < 0.01）。本研究中维库溴铵未能降低对有害刺激的血流动力学反应，提示神经肌肉阻滞不会改变大鼠的麻醉深度。对于那些在检查麻醉剂对有害刺激的血流动力学反应之前需要在实验动物中诱导肌肉松弛的研究人员而言，了解这种“无效应”可能很重要。这些结果还对神经肌肉阻滞降低麻醉需求的能力提出质疑，并支持神经肌肉阻滞对麻醉状态无作用的观点。
