摘要:Objective To investigate the effects of different target plasma concentration(CT)of propofol adminislered by target controlled infusion(TCI)on mimmum alveolar concentration(MAC)of sevoflurane.Methods Adult patients aged 20-50 yr weighing 40-76 kg,classified as ASA Ⅰ or Ⅱ,undergoing elective abdominal surgery were randomly divided into 5 groups:P0,P1,P2,P3 and P4.Anesthesia was induced with 8% sevoflurane and intravenous remifentnil 1μg/kg and succinylcholine 1 mg/kg in all patients.After tracheal intubation the patients received propofol TCI.CT was set at 0,1,2,3,4 μg/ml in group P0,P1,P2,P3,P4 respectively.The first patient received sevofluranc at end-tidal concentration of3.0%,2.2%,2.0%,1.8%and 1.5%in group P0,P1,P2,P3 and P4 respectively.After at least 15 min of equilibration and when neuromuscular function returned to T4/T1≥0.7,skin incision was made.According to the patient's somatic responses,the end-tidal concentration of sevofhlrane was increased/decreased by 0.2%in the next patient.At least six independent crossover pairs were observed in each group.MAC of sevoflurane was determined.The interaction between sevoflurane and propofol was analyzed using linear regression and correlation analysis.Results The MAC of sevoflurane was 2.17%4-0.11%in group P0,1.90%±0.10%in group P1,1.47%4-0.19%in group P2,1.37%±0.13%in group P3 and 1.00%±0.10%in group P4 respectively.With increasing CT of propofol from group P1 to group P4,MAC of sevoflurane was decreasing.The linear regression equation of the interaction between sevoflurane and propofol was Y=2.17-0.212X,r=-0.946 9(P<0.05).Conclusion With increasing CT of propofol from group P1 to group P4,the MAC of sevotlurane decreases by 12%,32%,37%and 54%respectively.Propofol and sevoflurane interact in an additive manner to produce immobility during skin incision.%目的 评价不同靶浓度异丙酚对七氟醚MAC的影响.方法 择期全麻下行腹部手术的病人,年龄20~50岁,ASA Ⅰ或Ⅱ级,随机分为5组,P0组、P2组、P3组、P4组和P4组均吸入8%七氟醚麻醉诱导,意识消失后静脉注射琥珀胆碱1 mg/kg和瑞芬太尼1 μg/kg.气管插管后行机械通气,P1组、P2组、P3组和P4组靶控输注异丙酚,血浆靶浓度分别为1、2、3、4 tμg/ml,P0组、P1组、P2组、P3组和P4组第1例病人七氟醚呼气末浓度分别为3.0%、2.2%、2.0%、1.8%和1.5%,当七氟醚呼气末浓度平衡15 min以上且神经肌肉功能恢复后开始切皮,根据是否发生切皮反应,采用up-down方法确定下一例病人的七氟醚呼气末浓度,每组出现6个交叉点后终止研究,以6个交叉点病人七氟醚呼气末浓度的均数为MAC.七氟醚MAC与异丙酚血浆靶浓度间分别进行直线回归和等级相关分析.结果 Pn组~P4组七氟醚MAC分别为2.17 4-0.11%、1.90%±0.10%、1.47%±0.19%、1.37%±0.13%和1.00%±0.10%;与P0组相比,P1组~P4组七氟醚MAC均降低,且呈浓度依赖性(P<0.05).七氟醚MAC(Y)与异丙酚血浆靶浓度(X)间的直线回归方程为Y=2.17-0.212 X,相关系数为-0.946 9(P<0.05).结论 异丙酚血浆靶浓度1~4 μg/ml可使七氟醚MAC分别降低12%、32%、37%和54%,两者以相加作用的方式抑制切皮反应.