靶控输注异丙酚意识消失时血浆和效应室靶浓度的EC（50）与脑电双频谱指数的关系 多中心大样本临床研究

Relationship between bispectral index and target plasma and effect-site EC50 for propofol by targetcontrolled infusion at loss of consciousness： a multicenter clinical study

目的 研究择期手术患者靶控输注（TCI）异丙酚意识消失时血浆、效应室靶浓度的50%患者意识消失时的药物浓度（EC50）与脑电双频谱指数（BIS）的关系。方法 5家医疗中心405例择期手术患者（国人）,ASAⅠ或Ⅱ级。靶控输注异丙酚,以血浆靶浓度1．2μg/ml为起点,到达预期血浆靶浓度后每30秒递增0．3μg/ml,直至患者意识消失。采用概率单位回归分析计算患者意识消失时异丙酚血浆靶浓度、效应室靶浓度的EC05、EC50和EC95及其所对应的BIS。结果 择期手术患者TCI异丙酚意识消失时异丙酚血浆靶浓度EC05、EC50和EC95分别是2．9μg/ml、3．8μg/ml和4．8μg/ml,效应室靶浓度EC05、EC50和EC95分别是1．3μg/ml、2．2μg/ml和3．2μg/ml,50%患者意识消失的BIS是58,5%和95%患者意识消失的BIS分别是77和40。结论 择期手术患者TCI异丙酚意识消失时血浆靶浓度和效应室靶浓度EC50及95%置信区间分别是3．8μg/ml（3．8～3．9μg/ml）和2．2μg/ml（2．2～2．3μg/ml）, 50%患者意识消失的BIS用95%置信区间是58（58～59）。

Objective To investigate the relationship between bispectral index （BIS） and target plasma andeffect-site EC50 for propofol given by target-controlled infusion （TCI） at loss of in Chinese patients scheduled for elective operation. Methods Four hundred and five ASA Ⅰ or Ⅱ Chinese patients （97 male, 308 female） aged 18-64 yr scheduled for elective operation in 5 medical centers were anesthetized with propofol by TCI using Diprifiusor TCI system incorporating Graseby 3500 infusion pump controlled by a computer programmed with the pharmacokinetic set of Marsh et al. The TCI of propofol was started at a target plasma concentration of 1.2 μg/ml, followed by increments of 0.3 μg/ml at 30 s intervals until the patient lost A quantal response model （probit analysis） was used to calculate the target plasma and effect-site EC05, EC50 and ED95 for propofol. HR, MAP, SpO2 and BIS were continuously monitored before and during anesthesia and recorded. Results The target effect-site EC05, EC50 and EC95 for prepofol at loss of were 1.3, 2.2 and 3.2 μg/ml respectively, while the target plasma EC05, EC50 and ED95 for propofol at loss of while 5 % The target were 2.9, 3.8 and 4.8 μg/ml. Fifty and 95 % of the patients lost percent of the patients lost consciousness at a BIS value of 58 ; at the BIS values of 77 and 40 respectively. Conclusion plasma and effect-site EC50 for propofol at loss of were 3.8 μg/ml （3.8-3.9 μg/ml） and 2.2 μg/ml （2.2-2.3 μg/ml） respectively in Chinese patients. The BIS value at loss of consciousness was 58 （58- 59）.