The study of proper depth of muscle relaxant in posterior fossa surgery under total intravenous anesthesia / 临床麻醉学杂志

Objective To investigate the proper depth of muscle relaxant without affecting elec-trophysiological monitoring in patients undergoing posterior fossa surgery under total intravenous an-esthesia (TIVA).Methods Forty patients selected for posterior fossa surgery were randomly divided into two groups A and B.Group A:no muscle relaxants were administered after anesthesia induction until the EMG was completed.Group B:muscle relaxants maintained in range of TOF 2%-25% dur-ing electrophysiological monitor.TIVA were used to all patients and BIS was maintained in range of 40-60.Two electrophysiological data were applied during the electrophysiological monitoring:sponta-neity EMG and evoked EMG.EMG amplitude was recorded at different TOF value.Operation time and the dosages of propofol,sufentanil,rocuronium bromide were recorded.Also,the SBP,DBP,HR at perioperational period and facial nerve function before surgery,one week and six months after sur-gery were recorded.Results The electrophysiological monitoring completed successfully in all pa-tients.The total amount of propofol in group A significantly increased than those in group B(P <0.05).Three patients in group A had body movement during the operation.Four cases in group B couldn??t perform electrophysiological monitor when the TOF had three signals.There were no differ-ence between the two groups in SBP,DBP,HR and facial nerve function.Conclusion Maintaining TOF value in range of 2%-25% under non-depolarizing muscle relaxant during CPA surgery doesn??t affect intraoperative nerve electrophysiological monitor and prevent body movement,total dose of sed-ative anesthetics is also decresed.

Application of different anesthesia ways in facial nerve monitoring during resections of acoustic neuromas / 中华神经医学杂志

Objective To investigate the feasibility and differences of two anesthetic methods (sevoflurane combined with remifentanil and propofol combined with remifentanil) in facial nerve monitoring without muscle relaxant during resection of acoustic neuromas.Methods Sixty-three patients with acoustic neuromas,admitted to our hospital from October 2011 to December 2012 and performed intraoperative monitoring of facial nerve without muscle relaxant assisted anesthesia,were collected in our study,and they were divided into two groups:sevoflurane combined with remifentanil treatment group (group S,n=32) and propofol combined with remifentanil treatment group (group P,n=31).The mean arterial pressure (MAP),heart rate (HR),intraoperative body movement and facial nerve were monitored and compared during the home invasion (T0),cuttng skin (T1),exploration of the facial nerve (T2),treatment of tumor near the brainstem (T3) and finishing of operation (T4).Results The MAP and HR were stable during the operation in patients of group P,without significant difference between each two observation time points (P＞0.05).Higher MAP and lower HR in the patients of group S at T2 and T3 were noted as compared with those in patients of group S at T0 and patients of group P at each same time point (P＜0.05).Facial nerve monitoring was completely possible and the anesthesia was effective in two groups.No obvious body movement was noted during the operation.Conclusion Two methods (sevoflurane combined with remifentanil and propofol combined with remifentanil) in facial nerve monitoring without muscle relaxant during resection of acoustic neuromas are completely possible and effective,and the latter one provides better hemodynamics.

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

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.