Effects of atracurium on facial nerve monitoring during otologic operations / 中国微创外科杂志

ABSTRACT

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 mastoidectomy under general anesthesia were selected.Anesthetic inducement was made with sufentanil at 0.4 ?g/kg,lidocaine 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 neuromuscular transmission monitor(TOF Guard) and the NMB level of right musculus adductor pollicis was assessed with the Nerve Integrity Monitoring 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 after 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 atracurium,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.