Objective To evaluate the precision of Diprifusor target-controlled infusion (TCI) system and investigate the ED50 of target propofol concentrations(C1) at differential stages of induction, maintenance and recovery in patients undergoing total intravenous anesthesia (TIVA) . Methods One hundred and two patients scheduled for elective surgery under general anesthesia were assigned to three groups (n=34): group A (age 19-45 years) , group B(46-64 years) and group C(65-80 years). All the patients were given TIVA using target-controlled infusion of propofol and bolus injection of fentanyl and vecuronium bromide. Adjustment of Ct depended on the requirements of operation and vital signs of the patient. 3 mL venous blood sample was drawn in 15 patients who were randomly selected from each age group. Plasma propofol concentration (Cm) was assayed by high-performance liquid chroma-tography (HPLC). Results In this TCI system, the median prediction error (MDPE) was -9.43% and the median absolute prediction error (MDAPE) was 25. 29% . The ED50 of Ct in groups A, B and C were 3.48, 2.82 and 2.50 μg/mL, respectively during induction stage; 2.39, 1.96 and 2.01 μg/mL, respectively during maintenance stage; and 1.02, 0.90 and 0.79 μg/mL, respectively during recovery stage. The higher the age was, the lower the ED50 of Ct was in three stages. Except that there was no significant difference between group B and C during maintenance stage (P0.05 ) , there were significant differences between other pairs (P0.01). Conclusion The feasibility and accuracy of Diprifusor TCI system of propofol in patients undergoing TIVA are clinically acceptable. Ct is more accurate during maintenance stage than induction or recovery stage. There is increasing sensitivity to propofol in the elderly patients. Besides, lower Ct should be in the elderly than the adult,because they have more adverse events.

AIM:To establish a reversed-phase HPLC method with fluorescence detection for determination of the concentration of propofol in human plasma. METHODS: Agilent 1100 HPLC instrument was used with the column : Diamonsil C 18(150 mm×4.6 mm,5 μm), Phenomenex Security Guard column(4 mm×3 mm). Plasma samples were precipitated with the thymol (internal standard) methanol solution. 20 μL of supernatant fluid was injected for HPLC analysis. The mobile phase was composed of acetonitrile-water(56:44,V/V).The flow rate was 1.5 mL·min -1. The fluorescence detective wavelengths were: λ ex=276 nm, λ em=312 nm. RESULTS: The standard curve equation was Y= 1.787C- 0.031 (r= 0.9997,n=9).The linear range was (0.02—8.0) mg·L -1. The average recovery was 98.71 %.Intra- and inter-day precision(RSD%) were all less than 4.2 %. The limit of detection was 4 μg·L -1(S/N=2). CONCLUSION:The RP-HPLC method is simple, sensitive and accurate for monitoring propofol concentration in clinical plasma samples.

异丙酚可用于椎管内麻醉病人的清醒性镇静,有效缓解病人术中听到手术器械声响或内脏牵拉引起的紧张、焦虑和不适,但病人之间的异丙酚推注速度和用量存在显著的个体差异.

目的观察Diprifusor靶控输注(TCI)用于不同年龄组椎管内麻醉清醒性镇静作用.方法 45例ASAⅠ～Ⅱ级、择期硬膜外麻醉和/或腰麻的病人,按照年龄分为三组,每组15例:成年组19～45岁、中年组46～64岁和老年组65～80岁.术中以Diprifusor TCI系统行丙泊酚清醒性镇静,采用5分镇静评分法,根据病人反应及所需镇静水平调节靶浓度(Ct).Ct初设值为0.4 μg/ml,每次调节量为0.1 μg/ml,时间间隙不小于3 min.结果老年组病人镇静评分为2、3和4时丙泊酚Ct的ED50分别为0.63 μg/ml、0.94 μg/ml和1.28 μg/ml,低于成年组1.00 μg/ml、1.34 μg/ml和1.66 μg/ml(P<0.01)和中年组0.80 μg/ml、1.10 μg/ml和1.51 μg/ml(P<0.05).成年组和中年组的丙泊酚Ct的ED50比较无显著差异.老年组病人镇静评分达4时,有5例(33.3%)出现低血压及心动过缓,3例(20%)出现呼吸抑制,都高于成年组和中年组的发生率.结论 Diprifusor TCI系统可以用于椎管内麻醉清醒性镇静.但随着年龄的增加,椎管内麻醉清醒性镇静所需丙泊酚Ct降低,不良反应增多.