Facial And Body Muscle Nerve Induced Potential Differences Of The Interaction Between Rocuronium Reaction And The Change Of The Damaged

Objective:To compare the inhibitory effect and inhibitory time of non-depolarizing muscle relaxant rocuronium on evoked electromyogram (EEMG) among normal and injured facial nerve-innervated orbicularis oris and tibial nerve-innervated gastrocnemius. To evaluate different sensitivities to rocuronium among orbicularis oris muscles innervated by facial nerves and gastrocnemius muscle innervated by somatic nerve and the changes after the injury of facial nerves. 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 neuromuscular blockage.Methods:Left-sided acute facial nerve injury was induced by facial nerve crush axotomy using vessel clamps in6rabbits, which resulted in Sunderland Ⅱ injury, the other side as control. The EEMG responses in normal and injured facial nerve-innervated orbicularis oris and the tibial nerve-innervated gastrocnemius were recorded simultaneously in vivo. The changes of EEMG from the three groups of muscles under2×ED90dose of rocuronium were observed and expressed by the absolute values of EEMG and the percentage of evoked electromyogram inhibition (EEMG%). The onset time and the regression time of rocuronium were recorded as well.Results:The baseline EEMG of facial nerve-innervated orbicularis oris was significantly smaller than those of the tibial nerve-innervated gastrocnemius and the percentage of EEMG inhibition (EEMG%) of orbicularis oris was significantly lower than the corresponding values of gastrocnemius (P<0.05); The baseline EEMG of injured facial nerve-innervated orbicularis oris was significantly smaller than those of the normal facial nerve-innervated orbicularis oris (P<0.05); Under the effect of rocuromiun the amplitude of EEMG of injured facial nerve-innervated orbicularis oris was significantly smaller than those of the normal facial nerve-innervated orbicularis oris (P<0.05), whereas no significant differences were found regarding EEMG%(P>0.05). These was no significant difference found in the onset time and the regression time among the three groups of muscles (P>0.05).Conclusions:The EEMG response of facial nerve-innervated orbicularis oris is less sensitive to rocuronium than that of tibial nerve-innervated gastrocnemius. The amplitude of EEMG of injured facial nerve-innervated orbicularis oris was smaller than those of the normal facial nerve-innervated orbicularis oris. There is no difference in the sensitivity to rocuronium between normal and injured facial nerve-innervated orbicularis oris. There is no difference in the onset time and the regression time of rocuronium among the normal or injured facial nerve-innervated muscles and somatic nerve innervated muscles. Objective:To compare the inhibitory effect and inhibitory time of non-depolarizing muscle relaxant rocuronium on evoked electromyogram (EEMG) for orbicularis oris innervated by different levels of damaged facial nerves. To evaluate the degree and time related changes in EEMG in response to rocuronium under different degrees of facial nerve injuries and after different time courses of injuries. To provide information for the proper usage of muscle relaxants to balance the requirement of EEMG monitoring and immobility in general anesthesia for patients with pre-surgical facial nerve injuries according to the somatic neuromuscular blockage.Methods:Left-sided acute facial nerve injury was induced by facial nerve crush axotomy using vessel clamps in72rabbits, which resulted in Sunderland Ⅰ-Ⅲ injury. To record the EEMG responses in normal or injured facial nerve-innervated orbicularis oris simultaneously in7days,14days,28days and42days postoperatively; The changes of EEMG responses under2×ED90doses of rocuronium were observed and expressed by the absolute values of EEMG and the percentage of evoked electromyogram inhibition (EEMG%). The onset time and the regression time of rocuronium were recorded as well.Results:The baseline EEMG of Sunderland Ⅱ-Ⅲ injured facial nerve-innervated orbicularis oris was significantly smaller than those of the normal ones (P<0.05); Under the effect of rocuromiun the amplitude of EEMG of injured facial nerve-innervated orbicularis oris was significantly reduced than those of the normal ones (P<0.05). Under the same time course, the baseline EEMG and amplitude of EEMG of injured facial nerve-innervated orbicularis oris in response to rocuromiun was negatively correlated with the degrees of facial nerve damages (P<0.001). Under the same degrees of injury, the baseline EEMG and amplitude of EEMG of injured facial nerve-innervated orbicularis oris in response to rocuromiun was not significantly correlated with the recovery time (P>0.05).There was no significant difference found in the onset time, the regression time or EEMG%among the three different degrees of nerve injuries and different recovery times (P>0.05).Conclusions:The baseline EEMG in injured facial nerve-innervated orbicularis oris was significantly reduced than those of the normal ones (P<0.05), while no changes in sensitivities to rocuronium were found; The more the severities of nerve injuries, the less the EEMG responses in the innervated muscles, but those kinds of changes were not found in the sensitivities to rocuronium; The longer the time courses after nerve injuries, the more the influences on EEMG responses by the degrees of nerve injuries in the innervated muscles, and likewisely, no changes in sensitivities to rocuronium were found. Under the defined levels of nerve injuries, the EEMG responses were not affected by the time courses of injuries. The onset time and the regression time of rocuromiun were not effected by the degrees and time courses of facial nerve injuries.