Objective To evaluate the accuracy of auditory evoked potential index (AAI) in monitoring the anesthetic depth during isoflurane anesthesia.Methods Thirty ASA Ⅰ or Ⅱ patients aged 18-55 years and undergoing elective surgery under general anesthesia were enrolled in this study. The patients were unpremedicated. Anesthesia was induced with midazolam 0.05 mg/kg, fentanyl 3 μg/kg and propofol 1 mg/kg. Tracheal intubation was facilitated with recuronium 0.1 mg/kg. The patients were mechanically ventilated (VT:40 mm Hg. Anesthesia was maintained with isoflurane inhalation and intermittent intravenous boluses of vecuronium. Isoflurane was started with high-flow (FGF, 3 L/min) for 12 min followed by low-flow (LGF, 0.5 L/min). The inspired isoflurane concentration was set at 3%. The electrocardiogram (ECG), mean arterial pressure (MAP), heart rate (HR), pulse oxygen saturation (SpO2), end-tidal isoflurane concentration and AAI were continuously monitored during anesthesia and recorded before induction of anesthesia (baseline, To ), immediately after induction (T1), immediately before isoflurane inhalation (T2), at 3 min(T3), 6 min (T4), 9 min (T5) and 12 min (T6) during high-flow wash-in and at the end-tidal isoflurane concentrations of 0.8 MAC (T7), 1.0 MAC (T8) and 1.3 MAC (T9) during low-flow inhalation of isoflurane, respectively.Results AAI decreased gradually while the end-tidal isoflurane concentration increased during high-flow wash-in. And AAI was negatively correlated with the end-tidal isoflurane concentrations ( r = -0.896, P ＜ 0.01 ) during low-flow inhalation of isoflurane anesthesia.

Objective To compare the efficacy of different target concentrations of etomidate in combination with midazolam,fentanyl and rocuronium used to induce anesthesia for tracheal intubation.Methods Eighty ASA Ⅰ or Ⅱ and Mallampati Ⅰ or Ⅱ patients of both sexes,aged 25-50 yr,weighing 57-76 kg,scheduled for elective non-cardiac surgery under general anesthesia,were randomly allocated into 4 groups according to the target effect-site concentration of etomidate (n =20 each) ∶ 0.5 μg/ml group (group E0.5),0.7 μg/ml group (group E0.7),0.9μg/ml group (group E0.9) and 1.1 μg/ml group (group E1.1).The patients were unpremedicated.Anesthesia was induced with midazolam 0.05 mg/kg,fentanyl 3 μg/kg,rocuronium 0.6 mg/kg and etomidate given by target-controlled infusion.When the effect-site concentration of etomidate reached 0.5,0.7,0.9 or 1.1 μg/ml,endotracheal intubation was performed.Auditory evoked potential index was recorded before induction of anesthesia (baseline),immediately before intubation,during insertion of the laryngoscope,and at 1,3 and 5 min after intubation.Myoclonus,injection pain,the requirement for vasoactive agents and burst suppression (BS) were recorded during induction of anesthesia.Results Compared with group E0.5,the requirement for urapidil was significantly decreased in group E0.7,the requirement for esmolol and urapidil was significantly decreased and the incidence of BS was increased in group E0.9,the requirement for esmolol and urapidil was significantly decreased,and the requirement for atropine and ephedrine and incidence of BS were increased in group E1.1 (P ＜ 0.05).The incidence of BS was significantly higher in group E0.9,and the requirement for atropine and incidence of BS were significantly higher in group E1.1 than in group E0.7 (P ＜ 0.05).The incidence of BS was significantly higher in group E1.1 than in group E0.9 (P ＜ 0.05).There was no significant difference in auditory evoked potential index and incidences of myoclonus and injection pain among the four groups (P ＞ 0.05).Conclusion The optimum target concentration of etomidate is 0.7μg/ml when combined with midazolam,fentanyl and rocuronium used to induce anesthesia.

Objective To investigate the effects of different doses of esketamine combined with ropivacaine on rebound pain after arthroscopic shoulder surgery under superior trunk brachial plexus block.Methods Ninety patients,including 35 males and 55 females,aged 18-60 years,BMI 18.5-28.0 kg/m2,ASA physical status Ⅰ or Ⅱ,were selected for shoulder arthroscopy.According to the method of random number table,the patients were divided into three groups:group El,group E2 and group R,30 pa-tients in each group.Three groups of patients with nerve block local anesthetic drugs were allocated accord-ing to the following scheme.In group El,0.2％ropivacaine,esketamine 0.25 mg/kg,and normal saline total 10 ml.In group E2,0.2％ropivacaine,esketamine 0.5 mg/kg,and normal saline total 10 ml.In group R,0.2％ropivacaine and normal saline total 10 ml.General anesthesia was implemented for all pa-tients after the nerve block anesthesia.HR,MAP,and surgical pleth index(SPI)were recorded before nerve block(T1),30 minutes after nerve block(T2),laryngeal mask placement(T3),and 30 minutes during surgery(T4).The NRS scores and the occurrence of rebound pain were recorded at rest and exercise 6,8,12,24,and 48 hours after surgery.The onset time and duration of sensory and motor block after an-esthesia,sedation score before and after anesthesia,sleep quality within 24 hours after surgery,and the oc-currence of adverse reactions within 48 hours after surgery were recorded.Results There were no significant differences in HR and MAP among the three groups at different time points.Compared with group R,the dosage of sufentanil in groups E1 and E2 were significantly reduced,and the NRS score at rest and exercise 12 to 48 hours after surgery were significantly decreased(P＜0.05).Compared with group R,the incidence of rebound pain in group E2 was significantly reduced,and the score of sedation after nerve block was significantly increased,the sleep time was significantly prolonged,and the sleep efficiency was signifi-cantly increased within 1 day after surgery(P＜0.05).Compared with group R,the incidence of postoper-ative adverse reactions such as nausea,vomiting,dizziness and headache in groups El and E2 within 48 hours after surgery were significantly reduced(P＜0.05).There were no significant differences in the onset and duration of sensory block among the three groups,and no motor nerve block occurred.Conclusion Es-ketamine 0.5 mg/kg combined with ropivacaine can reduce the incidence of rebound pain after shoulder ar-throscopy with brachial plexus block,improve postoperative sleep quality,but cannot shorten the onset time of sensory block and increase the duration of block.