阿曲库铵对耳外科手术面神经监测的影响

Effects of atracurium on facial nerve monitoring during otologic operations

目的探讨肌松剂阿曲库铵对面神经监测的影响。方法选择因慢性中耳炎须在全麻下行乳突根治术的患者20例，全麻诱导均采用舒芬太尼0．4μg／kg，利多卡因0．5—1mg／kg，丙泊酚2mglkg，氯化琥珀胆碱1．5mg／kg依次静注，气管插管后接麻醉机行机械通气，用TOF-GUARD肌松监测仪行右手拇内收肌肌松监测，用Medtronic多功能神经监测仪行面神经功能监测。术中刺激面神经引出面肌收缩肌电图之前不用肌松剂，而以舒芬太尼和丙泊酚静注维持麻醉。记录神经肌肉接头完全不被阻滞时的刺激电流阈值，术中刺激面神经成功引出面肌收缩肌电图信号之后，再给予阿曲库铵0．5mg／kg，神经肌肉接头达100％阻滞后再次刺激面神经，记录能够引出肌电图信号的刺激电流闷值。结果术中给予阿曲库铵前后均能维持患者麻醉平稳，安静不动；阿曲库钱应用后达到100％神经肌肉接头阻滞时，刺激面神经时面部肌肉收缩的肌电图信号依然能够引出，但刺激电流阈值从（0．224-0．09）mA增大至（0．394-0．17）mA（t=-8＋643，P=0．000）。结论阿曲库铵应用后周围神经肌肉阻滞达100％时依然可以进行面神经监测，但刺激电流阌值显著增大；可以在不用肌松剂的情况下，只用丙泊酚和舒芬太尼维持乳突根治手术的麻醉平稳。

Objective To investigate the effects of neuromuscular blockade （NMB） by atracurium on facial nerve monitoring. Methods Twenty patients with chronic otitis media scheduled for radical mastoideetomy under general anesthesia were selected. Anesthetic inducement was made with sufentanil at 0.4μg/kg, lidoeaine at 0. 5 - 1 mg/kg, propofol at 2 mg/kg, and scoline at 1.5 mg/kg in their given order intravenously. After endotracheal intubation, mechanical ventilation was employed with an anesthetic machine. Intraoperative facial nerve minitorization was performed using the neuromusculartransmisslon monitor （TOF Guard） and the NMB level of right musculns adductor pollicis was assessed with the Nerve Integrity Monitaring System（ Medtronic Inc. ） simultaneously. No muscle relaxants were given until the electromyogram （EMG） of the facial nerve-was induced, Propofol and sufentanil was administered intravenously to maintain the anesthesia. Minimal facial nerve stimulations-（regarded as-thresholds） causing EMG responses were measured during both nil NMB and 100% NMB by atracurium at 0.5 mg/kg. Results： With propofol and sufentanil intravenously administered, the anesthesia was maintained successfully both before and atter the administration of atracurium. The EMG of the facial nerve was induced even during the 100% NMB level by atracurium, but the thresholds were elevated significantly from 0.22 ± 0.09 mA to 0.39 ± 0.17 mA （ t = - 8. 643, P = 0. 000）. Conclusions, Facial nerve..monitoring can be performed even during the 100% NMB level by atraeurium, with significant elevated stimulating thresholds. Propofol and sufentanil can be used to maintain adequate level of anesthesia without the need of muscle relaxants in radical mastoidectomy.