Efficacy of anesthesia with BIS-guided etomidate TCI in combination with iv remifentanil infusion for noncardiac surgery: a prospective randomized single-blinded multicenter controlled clinical study

Objective To evaluate the efficacy of anesthesia with etomidate administered by TCI in combination with continuous iv remifentanil infusion titrated to maintain BIS values at 40-60 for non-cardiac surgery in a prospective randomized single-blinded multicenter controlled clinical study.Methods Two hundred and forty-four ASA Ⅰ or Ⅱ patients of both sexes aged 20-60 yr undergoing non-cardiac surgery lasting less than 3 h were randomly allocated into 2 groups:etomidate group (group E,n =123) and propofol group (group P,n =121 ).The patients were unpremedicated.A bolus of midazolam 0.03 mg/kg was injected iv immediately before induction of anesthesia.Anesthesia was induced with sufentanil 0.3-0.4 μg/kg and TCI of etomidate (effect-site concentration (Ce) =0.5-1.0 μg/ml) or propofol (Ce =3-4 μg/ml).Tracheal intubation was facilitated with rocuronium 0.9 mg/kg.The patients were mechanically ventilated (VT 8-10 ml/kg,RR 10-12 bpm,FiO2 =1 ).PETCO2 was maintained at 35-40 mm Hg.Anesthesia was maintained with TCI of etomidate ( Ce =0.3-0.8 μg/ml ) or propofol ( Ce =3-4 μg/ml) in combination with continuous iv infusion of remifentanil at 0.1-1.0 μg· kg-1 ·min-1 and intermittent iv boluses of rocuronium.BIS values were maintained at 40-60 during operation.Sufentanil 0.1 μg/kg was administered iv before skin closure.Ce at loss of consciousness,during maintenance of anesthesia and at emergence,the consumption of remifentanil and vasoactive agents,the emergence time and extubation time were recorded.The incidences of injecton pain,post-operative nausea and vomiting (PONV) and emergence agitation were measured.Results Ce of etomidate at loss of consciousness,at emergence and during maintenance of anesthesia was (0.50 ± 0.22),(0.16 ± 0.09) and 0.22-0.39 μg/ml respectively.The incidence of injection pain and the consumption of vasoactive agents were significantly lower but more remifentanil was needed in group E than in group P (P ＜0.05 or 0.01).There was no significant difference in emergence time and extubation time between the 2 groups (P ＞ 0.05).The incidence of PONV and emergence agitation were significantly higher during recovery in group E than in group P ( P ＜ 0.05 ).Conclusion The hemodynamics is stabler during operation,but the incidence of PONV and emergence agitation are significantly higher during recovery in group E than in group P.Etomidate induces little injection pain. Key words: Etomidate; Propofol; Piperidines; Electroencephalography; Drug delivery systems