Objective

To assess laryngeal function in normal dogs administered isoflurane following partial clearance of alfaxalone or propofol.

Study design

Randomized experimental crossover study.

Animals

A group of 12 purpose-bred, male Beagle dogs.

Methods

Dogs were randomly assigned to one of two treatments: alfaxalone–isoflurane (ALF-ISO) or propofol–isoflurane (PRO-ISO) and anesthetized for three video laryngoscopy examinations. The alternate treatment occurred after ≥ 14 days interval. Examinations were performed after induction of anesthesia (LS-A), after 20 minutes of breathing isoflurane via a facemask (LS-B) and after a further 20 minutes of isoflurane (LS-C). Parameters of objective laryngeal function included inspiratory rima glottidis surface area (RGSA-I), expiratory rima glottidis surface area (RGSA-E) and % RGSA increase, calculated from three consecutive respiratory cycles in the final 15 seconds of each video laryngoscopy examination. The % RGSA increase was calculated using [(RGSA-I – RGSA-E)/RGSA-E] × 100. Subjective laryngeal function was evaluated independently by two experienced surgeons blinded to treatment.

Results

The % RGSA increase within each treatment was greater for LS-B and LS-C than for LS-A (ALF-ISO: p = 0.03, PRO-ISO: p = < 0.001). There was no difference within each treatment from LS-B compared with LS-C. RGSA-I increased within each treatment from LS-A to both LS-B and LS-C (ALF-ISO: p = 0.002) and to LS-C (PRO-ISO: p = 0.006). Subjective laryngeal function scores improved from LS-A to LS-C.

Conclusions and clinical relevance

Laryngeal function improved from postinduction examination following either 20 or 40 minutes of anesthesia with isoflurane via facemask. This study demonstrates that isoflurane may have a lesser effect on arytenoid abduction activity compared with more commonly used intravenous induction anesthetics (alfaxalone and propofol).

中文翻译：

---

正常犬在阿法沙酮或丙泊酚部分清除后给予异氟醚的喉功能

客观的

评估正常犬在阿法沙酮或丙泊酚部分清除后给予异氟醚的喉功能。

学习规划

随机实验交叉研究。

动物

一组 12 只专门饲养的雄性比格犬。

方法

狗被随机分配到两种治疗方法中的一种：阿法沙酮-异氟醚 (ALF-ISO) 或丙泊酚-异氟醚 (PRO-ISO)，并麻醉进行三项视频喉镜检查。间隔≥14 天后进行替代治疗。在麻醉诱导 (LS-A) 后、通过面罩 (LS-B) 吸入异氟醚 20 分钟后以及再吸入异氟醚 (LS-C) 20 分钟后进行检查。客观喉功能的参数包括吸气声门表面积 (RGSA-I)、呼气声门表面积 (RGSA-E) 和 RGSA 增加百分比，根据每个视频喉镜检查的最后 15 秒中的三个连续呼吸周期计算得出。使用 [(RGSA-I – RGSA-E)/RGSA-E] × 100 计算 RGSA 增加百分比。

结果

LS-B 和 LS-C 在每次处理中的 RGSA 增加百分比大于 LS-A（ALF-ISO：p  = 0.03，PRO-ISO：p  = < 0.001）。与 LS-C 相比，LS-B 的每个处理没有差异。RGSA-I 在从 LS-A 到 LS-B 和 LS-C（ALF-ISO：p  = 0.002）和 LS-C（PRO-ISO：p  = 0.006）的每次处理中增加。主观喉功能评分从 LS-A 提高到 LS-C。

结论和临床相关性

通过面罩用异氟醚麻醉 20 或 40 分钟后，喉功能从诱导后检查中得到改善。该研究表明，与更常用的静脉内诱导麻醉剂（阿法沙龙和丙泊酚）相比，异氟醚对杓类外展活动的影响可能较小。