罗库溴铵对家兔正常或受损面神经和肢体神经支配的肌肉诱发肌电位反应的影响

Effect of rocuronium on evoked electromyogram:comparison between normal and damaged facial nerve and somatic nerve-innervated muscles in rabbits

目的比较罗库溴铵对家兔正常或受损面神经支配的口轮匝肌、肢体神经支配的腓肠肌的诱发肌电位(EEMG)的抑制程度和抑制时间。分析面神经和肢体神经支配的肌肉对罗库溴铵敏感性的差异程度、面神经受损后的变化,为临床上施行术中面神经监测时,根据外周肌肉松弛程度制定术中肌肉松弛药使用方案提供实验依据。方法家兔6只,采用血管阻断夹钳夹法制备左侧面神经面颊支损伤模型。采用自体对照,同步记录正常或受损面神经支配的口轮匝肌和右侧胫神经支配的腓肠肌电刺激诱发的EEMG振幅;观察2倍90%有效剂量罗库溴铵作用下3组肌肉的EEMG变化程度,包括EEMG振幅(以EEMG绝对值表示)、受罗库溴铵作用的最大抑制程度[以EEMG抑制百分比(EEMG%)]表示,并记录罗库溴铵的起效时间和失效时间。结果面神经正常侧和受损侧口轮匝肌用药前的EEMG绝对值均显著小于腓肠肌(P值均<0.05),面神经受损侧口轮匝肌用药后的EEMG绝对值亦显著小于腓肠肌(P<0.05)。面神经正常侧和受损侧口轮匝肌的EEMG%均显著小于腓肠肌(P值均<0.05)。面神经受损侧口轮匝肌用药前后的EEMG绝对值均显著小于面神经正常侧口轮匝肌(P值均<0.05)。面神经正常侧口轮匝肌与腓肠肌间用药后的EEMG绝对值、面神经正常侧口轮匝肌与面神经受损侧口轮匝肌间EEMG%的差异均无统计学意义(P值均>0.05)。面神经正常侧和受损侧口轮匝肌、腓肠肌三者间罗库溴铵起效时间和失效时间的差异均无统计学意义(P值均>0.05)。结论面神经支配的口轮匝肌的EEMG反应对非去极化肌肉松弛药罗库溴铵的敏感性明显低于肢体神经支配的腓肠肌。面神经受损后,所支配肌肉的EEMG反应较正常时明显降低,但对罗库溴铵的敏感性没有变化。罗库溴铵对于面神经和肢体神经支配的肌肉,起效时间和失效时间的差异均无统计学意义,面神经受损后也无明显改变。

Objective To compare the inhibitory effect and inhibitory time of rocuronium on evoked electromyogram （EEMG） between normal and injured facial nerve-innervated orbicularis oris and tibial nerve- nnervated gastrocnemius. To evaluate the different sensitivities to rocuronium among the muscles innervated by facial and somatic nerves, and the changes after facial nerve injuries, so as to provide information for the proper usage of muscle relaxants to balance the requirement of EEMG monitoring and immobility in general anesthesia according to the somatic neuromuscular blockage. Methods Left-sided acute facial nerve injury was induced by facial nerve crush axotomy using vessel clamps in 6 rabbits. By using auto-paired control, the EEMG responses in normal and injured facial nerve-innervated orbicularis oris and the right tibial nerve-innervated gastrocnemius were recorded simultaneously in vivo. The changes of EEMG from the three groups of muscles under 2 x 90 % effective dose of rocuronium were observed and expressed by both amplitude of EEMG （absolute value） and the percentage of EEMG （EEMG%）. The onset time and dead time of rocuronium were recorded. Results The baseline EEMG amplitude and EEMG% of facial nerve-innervated orbicularis oris were significantly lower than those of tibial nerve- innervated gastrocnemius （all P^0.05）. After administration of rocuronium, EEMG amplitude of injured facial nerve-innervated orbicularis oris was significantly smaller than that of injured tibial nerve-innervated gastrocnemius （P~ 0. 05）. EEMG amplitude of injured orbicularis oris before and after administration of rocuronium were significantly smaller than those of normal orbicularis oris （both P^0.05）. However, there were no significant differences in EEMG amplitude between normal orbicularis oris and normal gastrocnemius after administration of rocuronium or in EEMG% between normal and injured orbicularis oris （both P^0.05）. These was no significant difference in the onset time or dead time of rocuronium among the three groups of muscles （all P ~ 0. 05）. Conclusion The EEMG response of facial nerve-innervated orbicularis oris is less sensitive to rocurenium than that of somatic nerve-innervated gastrocnemius. The amplitude of EEMG of facial nerve-innervated muscles is significantly reduced after nerve damage, whereas the sensitivity to rocuronium is not changed. There is no significant difference in the onset time or dead time of rocuronium among the muscles innervated by facial and somatic nerves, even after facial nerve damage. （Shanghai Med J, 2013, 36 ： 828-832）