Sant'Ambrogio F B, Anderson J W, Nishino T, Sant'Ambrogio G
Department of Physiology and Biophysics, University of Texas Medical Branch, Galveston 77555-0641.
Respir Physiol. 1993 Mar;91(2-3):237-46. doi: 10.1016/0034-5687(93)90102-g.
It has been previously found that volatile anesthetics significantly affect the activity of laryngeal receptors. In this study we have investigated the respiratory effects of these volatile anesthetics delivered into the upper airway of newborn and adult dogs. Experiments were performed on 17 5-14-day-old, 3 26-28-day-old and 3 adult dogs, anesthetized and breathing spontaneously through a tracheostomy. In the youngest age group, halothane decreased ventilation (VE) to 37.6 +/- 6.8% of control (mean +/- SE; P < 0.01) due to a decrease in both frequency and tidal volume. Peak inspiratory and expiratory flows, and esophageal pressure (Pes) were depressed also (60.8 +/- 6.5%, 51.6 +/- 7.1% and 66.5 +/- 8.1% of control, respectively; P < 0.01). Superior laryngeal nerve (SLN) section abolished the changes in VE, but residual significant decreases in peak flows and Pes were still present and disappeared only after topical anesthetization of the nasal cavities. Isoflurane had similar but weaker effects on VE (74.2 +/- 2.8% of control; P < 0.01), accompanied by a decrease in peak inspiratory and expiratory flows and Pes. SLN section abolished these changes. In the 26-28 day age group there was only a decrease in peak inspiratory airflow with the halothane challenge; isoflurane did not have any effect. In the adult dogs halothane caused only a marginal decrease in inspiratory time. The depressive effects of halothane and isoflurane should be considered when they are used for induction of anesthesia in newborns.
此前已发现挥发性麻醉剂会显著影响喉感受器的活性。在本研究中，我们调查了将这些挥发性麻醉剂输送到新生犬和成年犬上呼吸道后的呼吸效应。实验在17只5 - 14日龄、3只26 - 28日龄和3只成年犬身上进行，这些犬经气管切开术麻醉并自主呼吸。在最年幼的年龄组中，氟烷使通气量（VE）降至对照值的37.6 +/- 6.8%（平均值 +/- 标准误；P < 0.01），原因是频率和潮气量均下降。吸气和呼气峰值流速以及食管压力（Pes）也降低（分别为对照值的60.8 +/- 6.5%、51.6 +/- 7.1%和66.5 +/- 8.1%；P < 0.01）。切断喉上神经（SLN）消除了VE的变化，但峰值流速和Pes仍有显著下降，且仅在鼻腔局部麻醉后才消失。异氟烷对VE有类似但较弱的作用（为对照值的74.2 +/- 2.8%；P < 0.01），同时伴有吸气和呼气峰值流速以及Pes的下降。切断SLN消除了这些变化。在26 - 28日龄组中，氟烷激发试验仅使吸气峰值气流下降；异氟烷没有任何作用。在成年犬中，氟烷仅使吸气时间略有减少。在新生儿麻醉诱导中使用氟烷和异氟烷时，应考虑其抑制作用。
