持续输注丙泊酚药代动力学模型的选择

目的　将四种文献报道的药代动力学模型用于计算机模拟以预测持续输注丙泊酚的 血浆浓度,籍以选择适合中国人的药代动力学模型。方法　选择ASAⅠ～Ⅱ级的择期手术病人16 例,≥65岁(Ⅰ组)病人静脉输注丙泊酚速度60ml/h,<65岁(Ⅱ组)者输注速度75ml/h,抽取动脉血 分析药物血浆浓度,用四种药代动力学模型预测丙泊酚血浆浓度,计算样本加权残差(WR)、绝对值 加权残差(absWR)。结果　Schuttler模型在Ⅰ组病人,中位数加权残差(MDWR)显著小于其他三种 参数(P<0.01),对所有病人输注期间预测浓度 实测浓度的拟合程度最好(P<0.01)。结论　仅 Schuttler药代动力学模型适合用于持续静脉输注丙泊酚期间和停止输注后的药物浓度预测。     

靶控输注异丙酚的临床应用和准确性评价

目的 评估内嵌Marsh等报道的药代学参数的TCI系统的准确性。方法 22例ASAⅠ-Ⅱ级择期手术患者，＜65岁（Y组）和＞65岁（E组）各11例，异丙酚靶浓度从2μg/ml开始以1μg/ml递增直至意识消失，分析血浆浓度。计算每个样本的百分比预测误差（％PE），稳定误差（％CE）和组间个体内中位数预测误差（MDPE），中位数绝对误差（MDAPE），中位稳定误差（MDCE），中位数绝对稳定误差（MDACE）。结果 升高靶浓度时系统产生明显的超射。E组异丙酚血浆浓度的PE和绝对值PE分别是63．3％和66．2％，Y组则分别是62．1％和62．7％。E组CE和绝对值CE分别是－0．3％和12．7％，Y组则分别是0．6％和13．5％，组间无差异（P＞0．05）。E组和Y组中位数MDPE（＝中位数MDAPE）分别为78．1％和66．1％，MDCE分别是－0．2％和0．8％，MDACE分别是12．5％和13．5％。实测浓度和预测浓度呈显著直线相关（P＜0．01）。结论 Marsh参数用于国人靶控输注，实测浓度和预测浓度的差异性较大，但系统能够维持稳定的血浆浓度。     

Marsh和Schnider药代动力学参数用于患者异丙酚靶控输注系统准确性的比较

目的 比较Schnider和Marsh药代动力学参数用于患者异丙酚TCI系统的准确性.方法 择期腹腔镜妇科手术患者40例,ASA分级Ⅰ或Ⅱ级,年龄25 ～ 55岁,采用随机数字表法,将其随机分为2组(n=20):Marsh药代动力学参数组(M组)和Schnider药代动力学参数组(S组).麻醉诱导:TCI异丙酚(血浆靶浓度4 μg/ml)和瑞芬太尼(血浆靶浓度2 ng/ml),意识消失后静脉注射罗库溴铵0.6 mg/kg,气管插管后行机械通气,调节潮气量和通气频率,维持PET CO2 35～ 45 mm Hg.麻醉维持:TCI瑞芬太尼,血浆靶浓度4 ng/ml,调节异丙酚血浆靶浓度3～5 μg/ml,维持BIS值40 ～ 50.分别于气腹建立后15、30、45 min时采集静脉血样,采用高效液相色谱-荧光法检测血浆异丙酚浓度.计算TCI系统的偏离度和精确度.结果 M组TCI系统的偏离度和精确度均为55％,S组TCI系统的偏离度和精确度分别为39％和41％.结论 内嵌Marsh和Schnider药代动力学参数异丙酚TCI系统可用于手术患者,而后者的准确性较前者高,但是仍需要进一步优化.     

丙泊酚靶控输注Marsh模式和Schnider模式在宫腔镜手术中的应用比较

目的比较丙泊酚靶控输注Marsh模式和Schnider模式在宫腔镜手术中的应用效果。方法选取2017年1月至2018年6月于中山大学孙逸仙纪念医院择期行宫腔镜手术患者60例,年龄20～60岁,BMI 18～30,ASA分级Ⅰ～Ⅱ级,分为两组,Marsh组(M组),n=30和Schnider组(S组),n=30。两组分别以Marsh模式和Schnider模式靶控输注丙泊酚进行麻醉,并用Narcotrend监测麻醉深度。记录手术时间、丙泊酚用量、术中体动次数、调整TCI参数次数、术中低血压次数、窦性心动过缓次数、辅助呼吸次数。采集基础状态(T_0)、意识消失(T_1)、扩张宫颈(T_2)、麻醉结束(T_3)时的NTI。并记录苏醒时间、恶心呕吐和寒战例数。结果M组和S组两组患者ASA分级、年龄、BMI、手术时间比较差异无统计学意义(P0.05);M组单位时间丙泊酚用量少于S组,差异有统计学意义(P0.01);M组患者术中体动次数多于S组,差异有统计学意义(P0.05),术中调整TCI参数次数也多于S组,差异有统计学意义(P0.01),但两组术中低血压、窦性心动过缓和辅助呼吸次数差异无统计学意义(P0.05);基础状态(T_0)时,M组和S组两组NTI比较差异无统计学意义(P0.05);在意识消失(T_1)和扩张宫颈(T_2)时,M组NTI高于S组,差异有统计学意义(P0.01);在麻醉结束(T_3)时,M组和S组两组NTI比较差异无统计学意义(P0.05);M组和S组两组患者苏醒时间、恶心呕吐和寒战例数比较差异无统计学意义(P0.05)。结论宫腔镜手术中,丙泊酚Schnider靶控输注模式优于Marsh模式。     

小儿异丙酚靶控输注系统准确性的评价

目的建立小儿异丙酚药代学参数的靶控输注(TCI)系统,评价系统的准确性。方法 24例ASA Ⅰ级择期手术小儿,分为2组(n=12),A组:≥3岁且<5岁;B组:≥5岁且<10岁,应用连庆泉等报道的小儿异丙酚药代动力学参数以及Stanpump软件,微机连接Graseby 3500输液泵。恒定血浆靶浓度3μg·ml-1变速输注持续1 h,间断采集动脉血持续1．5 h。用高效液相法测定异丙酚血浆药物浓度,并计算系统的执行误差中位数(MDPE)、不含TCI开始5 min的执行误差中位数(MDPE1)、执行误差绝对值的中位数(MDAPE)、分散度和摆动度。结果两组异丙酚的实测浓度在TCI开始40 min内均高于靶浓度(P<0．05),后渐接近靶浓度,至TCI 50 min时与靶浓度差异无统计学意义。停止 TCI后实测浓度比预测浓度低(P<0．01)。A、B组TCI期间系统的MDPE分别为27％和26％、MDPE1 分别为7％和12％、MDAPE分别为27％和26％、分散度分别为-0．75％·h-1和-0．80％·h-1、摆动度分别为23％和24％,停止TCI后系统的MDPE分别为-30％和-25％,MDAPE分别为30％和25％,摆动度分别为9％和9％,分散度分别为0．31％·h-1和0．38％·h-1。结论本研究中小儿TCI输注系统的偏离性较小,精确度较高且分散度小,能维持稳定的血药浓度,符合临床要求。     

不同年龄患者靶控输注丙泊酚的血药浓度与脑电双频指数值的相关性

目的研究靶控输注丙泊酚镇静时不同年龄患者的丙泊酚血药浓度与脑电双频指数(BIS)值的相关性。方法60例上腹部手术患者随机分为青壮年组(28~45岁,n=30)和老年组(65~80岁,n=30)。全麻诱导设定丙泊酚血浆靶控浓度3mg/L、雷米芬太尼7μg/L。意识消失后给予维库溴铵0.1mg/kg气管插管后行机械通气。术中雷米芬太尼靶控浓度维持不变,气管插后丙泊酚的靶控浓度降至2.5mg/L,术中调节丙泊酚的量使BIS值维持在45~55,并在调节后5min测定丙泊酚血药浓度。结果两组患者一般情况差异无统计学意义。青壮年组实测丙泊酚血药浓度与BIS值无相关性,老年组呈高度负相关(r=-0.64816)。结论青壮年组丙泊酚实测血药浓度与BIS值无相关性,而老年组有明显的负相关,说明在老年患者实测血药浓度可以评估镇静深度。     

老年人丙泊酚效应室靶控浓度与脑电双频指数变化的关系

目的探讨老年人靶控输注(TCI)丙泊酚时不同效应室靶控浓度与脑电双频指数(BIS)变化的关系,以及镇静和麻醉时效应室靶控浓度的适宜设置值。方法18例老年病人静脉TCI丙泊酚,血浆靶控浓度的设定从0·5μg/ml开始,当效应室靶控浓度上升到血浆靶控浓度水平时,将血浆靶控浓度调高0·5μg/ml,使丙泊酚血浆靶控浓度阶梯式上升,直到效应室靶控浓度达到3·5μg/ml。记录每个效应室靶控浓度水平时的MAP、HR、RR、SpO2、BIS值和Ramsay镇静评级,同时测定丙泊酚血药浓度。结果丙泊酚效应室靶控浓度与实测血药浓度呈高度直线相关(r=0·9982,P<0·01),预测误差中位数(MDPE)=5%,预测误差绝对值的中位数(MDAPE)=12·7%,摇摆率(Wobble)=12·0%。效应室靶控浓度与BIS值呈高度直线负相关(r=-0·9985,P<0·01),回归方程:BIS值=92·94-17·77×效应室靶控浓度值(R2=0·9771,P<0·01)。当效应室靶控浓度达到0·5μg/ml时,50%的病人镇静评级达到3级。效应室靶控浓度达到3·5μg/ml时,MAP的降幅达到基础值的34%,自主呼吸率稍有降低,吸氧条件下SpO2保持在95%以上。结论丙泊酚效应室靶控浓度与BIS值呈负相关,可以用其评估镇静深度。对于老年病人,丙泊酚效应室靶控浓度在0·5~1·0μg/ml时已获得临床镇静效果,2·0~2·5μg/ml时达到全麻诱导的要求。     

咪达唑仑靶控输注系统准确性的评价

目的 评价内嵌自行设计咪达唑仑药代动力学参数靶控输注(TCI)系统的准确性.方法 择期颅内肿瘤切除术患者23例,ASA Ⅰ或Ⅱ级,年龄20～60岁,均靶控输注咪达唑仑、瑞芬太尼和维库溴铵行麻醉诱导和维持.随机选择14例行全麻诱导咪达唑仑参数研究,静脉输注咪达唑仑20 μg·kg-1·min-1 20 min,于给药前,给药后1、3、5、7、10、15、20 min,停药后5、15、30、45 min、1、2、4、6、12、18、24 h分别取桡动脉血3 ml,采用反相高效液相法测定咪达唑仑血药浓度,计算其药代动力学参数.所得参数嵌入单片机控制输注泵行咪达唑仑TCI完成其余9例择期手术患者临床麻醉,比较咪达唑仑实测血药浓度与预测值,计算咪达唑仑的执行误差(PE)、执行误差绝对值(absPE)、执行误差中位数(MDPE)、执行误差绝对值中位数(MDAPE)、稳定误差(CE)、稳定误差绝对值(absCE)、稳定误差中位数(MDCE)、稳定误差绝对值中位数(MDACE).结果 咪达唑仑药代动力学符合三室模型;血浆咪达唑仑浓度的PE、absPE、MDPE、MDAPE分别为-2.4%、13.5%、-3.15%、13.59%.TCI系统患者个体内的CE、absCE、MDCE、MDACE分别为0、1.4%、0.03%、1.16%,实测浓度与预测浓度呈正相关(r=0.986,P＜0.05).结论 应用本组咪达唑仑药代动力学参数嵌入TCI系统的精确度和稳定性较好.     

丙泊酚在危重烧伤兔休克期的药代动力学变化

目的探讨丙泊酚在危重烧伤动物模型休克期的药代动力学特点。方法20只新西兰大白兔,随机均分为烧伤休克期组(S组)和对照组(C组)。将S组兔制成30%体表总面积(TB-SA)的Ⅲ度烫伤,并进行复苏,烫伤6h后单次静脉注射5·1mg/kg丙泊酚,利用高效液相色谱仪(HPLC)检测注药后1、3、10、20、30、45、60、90min兔血浆丙泊酚浓度。用3P97药代动力学计算程序处理血药浓度数据,拟合房室模型,计算药代动力学参数。结果各组分别有8只兔完成实验数据采集,S组血浆丙泊酚浓度在1min时明显低于C组(P<0·01),而从30min开始直至90min,明显高于C组(P<0·01)。S组符合二室开放模型,C组符合三室开放模型;S组中央室分布容积(VC)、曲线下面积(AUC)增大(P<0·01),消除半衰期(t1/2β)延长(P<0·05),清除率(CL)降低(P<0·05)。结论丙泊酚在危重烧伤兔模型中休克期药代动力学参数变化明显,较正常兔分布半衰期(t1/2α)、t1/2β延长,VC增大,CL降低。     

静吸复合麻醉中瑞芬太尼靶控输注系统的性能评价

目的评价腹腔镜手术病人静吸复合麻醉中瑞芬太尼靶控输注系统(Minto药代动力学参数)的性能。方法15例择期行腹腔镜手术,采用血浆靶控输注瑞芬太尼、吸入异氟烷和间断静脉注射维库溴铵维持麻醉。瑞芬太尼血浆目标浓度逐渐升高,每次浓度改变间隔时间30 min,目标浓度分别为3、6、9 ng/ml。于麻醉诱导前(空白对照血浆)和瑞芬太尼目标浓度改变后30 min时从桡动脉置管处采集血样,应用高效液相色谱质谱联用技术测定全血中瑞芬太尼浓度。采用执行误差(performance error,PE)的中位数(median performance error,MDPE)、PE绝对值的中位数(median absolute performance error,MDAPE)和摆动度(wobble)评价瑞芬太尼靶控输注系统的性能。结果瑞芬太尼靶控输注系统的MDPE、MDAPE和wobble分别为8.78%,16.11%和14.55%。实测浓度与目标浓度呈正相关(r=0.891,P=0.000),线性方程为Y∧=1.1046X 0.1837。结论瑞芬太尼靶控输注系统(Minto药代动力学参数)在临床应用浓度范围内能满足临床麻醉的要求。     

Pharmacokinetic Model Selection for Target Controlled Infusions of Propofol: Assessment of Three Parameter Sets

Background: Computer-assisted target controlled infusions (TCI) result in prediction errors that are influenced by pharmacokinetic variability among and within patients. it is uncertain whether the selection of a propofol pharmacokinetic parameter set significantly influences drug concentrations and clinical acceptability.

Methods: Thirty patients received similar propofol TCI regimens after being randomly allocated to one of three parameter sets. Arterial and venous concentrations were measured and prediction errors calculated from pooled and intrasubject data.

Results: Arterial propofol concentrations in the Dyck group revealed greater bias (mean 43%) than did those in the Marsh (-1%) and Tackley (-3%) groups. The Dyck group also showed greater inaccuracy (mean:47%) than the Marsh (29%) and Tackley (24%) groups. There was little tendency for measured concentrations to vary from targeted values over time (divergence). Variability about an observed mean in individual patients (wobble) was low. Venous propofol concentrations were initially much less than arterial concentrations, but this difference decreased over time.     

The performance of a target-controlled infusion of propofol in combination with remifentanil: a clinical investigation with two propofol formulations

Target-controlled infusion (TCI) incorporates the pharmacokinetic variables of an IV drug to facilitate safe and reliable administration. In this clinical study we investigated the performance of propofol TCI in combination with remifentanil. Fifty-four adult patients scheduled for general surgery lasting longer than 1 h received a combined TCI of propofol (Marsh parameter set; propofol randomly either dissolved with long- or middle-/long-chain triglycerides) and remifentanil. Arterial propofol plasma concentrations and hemodynamic and derived electroencephalogram variables were determined at various stages before, during, and after surgery. Measured propofol plasma concentrations exceeded the predicted values by 59%, and 48% when recalculated with the Schnider parameter set. Pharmacokinetic population analysis showed a small central volume of distribution (3.55 L) and reduced clearance (1.31 L/min) for propofol. ASA status and sex were the only variables that had a significant influence on propofol pharmacokinetics. In a second step, a new pharmacokinetic variable set for propofol was determined in the first 27 patients. Post hoc performance analysis of the remaining 27 patients showed improved accuracy using the new variable set. Our results show that when remifentanil and propofol are combined, the Marsh and Schnider parameter sets systematically underestimate propofol plasma concentrations. Presented, in part, at the Annual Meeting of the European Society of Anesthesiologists, Amsterdam, The Netherlands, June 1, 1999, and the Annual Meeting of the American Society of Anesthesiologists, Dallas, Texas, October 12, 1999.     

Target-controlled infusion of propofol induction with or without plasma concentration constraint in high-risk adult patients undergoing cardiac surgery

BACKGROUND: Calculated plasma (Cp) and calculated effect site concentrations (Ce) of propofol associated with loss of consciousness (LOC) have been studied in young healthy patients. The aim of the study was to evaluate the calculated propofol concentrations required to induce LOC in ASA III adult patients undergoing cardiac surgery using a smooth target controlled infusion of propofol. METHODS: After informed consent, 44 patients were premedicated with 0.5 mg alprazolam orally. Propofol TCI using the pharmacokinetic set of Marsh et al. incorporated in the Diprifusor (ThalfKeo of 2.6 min) was used. Propofol Ce was progressively increased by 0.5 micro g/ml until LOC was obtained. The constraint on the maximum gradient between Cp and Ce was either 1 micro g/ml in group 1 or not limited in group 2. Hemodynamic variations were assessed. RESULTS: Mean preoperative left ventricular ejection fractions were 44 +/- 15.4% and 56 +/- 11.4% in groups 1 and 2, respectively (P < 0.01). At LOC, mean Cp was 1.9 micro g/ml in both groups but mean Ce was 1.08 +/- 0.31 and 1.43 +/- 0.42 micro g/ml in groups 1 and 2, respectively (P < 0.01). The mean induction time was 12.8 +/- 7.1 min in group 1 and 8.5 +/- 2.7 min in group 2 (P < 0.05). No episode of hypotension has been observed in either group. CONCLUSION: In ASA III patients undergoing cardiac surgery, smooth propofol TCI induction, using the pharmacokinetic set of Marsh et al. incorporated in the Diprifusor, is associated with LOC at a low mean calculated plasma concentration of 1.9 micro g/ml and good hemodynamic stability.     

老年和青壮年病人异丙酚全麻诱导的药代动力学比较

目的 观察老年病人异丙酚单次静注全麻诱导的药动学特征,并与青壮年进行比较。方法18例ASAⅠ～Ⅱ级的择期手术病人,按照年龄大小分成两组,青壮年组(n=6,A组):年龄31～57岁(平均46.5岁),麻醉诱导用异丙酚1.5mg·kg-1、咪达唑仑0.03～0.06mg·kg-1、芬太尼3～5μg·kg-1和维库溴铵0.1mg·kg-1;老年组(n=12,E组):年龄67～81岁(平均74.0岁),再以75岁为界分成两个亚组,E1组(n=6,67～73岁,平均69.3岁)和E2组(n=6,76～81岁,平均78.7岁),麻醉诱导用异丙酚1.0mg·kg-1,其余同A组。经前臂静脉注射异丙酚,分别于注射前和注射后1、2、4、6、10、15、30、45、60、75、90、120、150、180、240、300、360min从右颈内静脉采血3ml,肝素抗凝、离心后取上层血浆于4℃下保存。用高效液相色谱荧光法检测血浆中异丙酚浓度,3P87软件计算药代动力学参数。结果18例病人异丙酚的药动学特征均符合三室开放模型,A组注药后1,2,4,6,10min的平均血药浓度值经剂量校正后均低于E组及其亚组(P<0.05),2min时尤为明显(P<0.01)。E组与E1组和E2组相比较,各数值间均无显著差异;E2组与E1组相比,仅T1/2β较长(p<0.05)。与A组相比,E组的Vc明显减少(P<0.01),CL显著下降(P<0.01),K31明显变小(P<0.01),T1/2β也较长(P<0.05)。结论 异丙酚用于老年人麻     

Impact of Bispectral Index Monitoring on Stress Response and Propofol Consumption in Patients Undergoing Coronary Artery Bypass Surgery

Background: Bispectral Index (BIS)-titrated administration allows a reduction of propofol infusion rates in patients undergoing surgery. Resulting differences in anesthetic depth might affect the stress response to surgery involving neural circuitry not reflected in the electroencephalogram.

Methods: Forty patients scheduled to undergo elective coronary artery bypass grafting receiving a background infusion of remifentanil (0.3 [mu]g [middle dot] kg-1 [middle dot] min-1) were anesthetized with intravenous propofol delivered by target-controlled infusion according to the Marsh pharmacokinetic model under BIS monitoring. In a randomized, prospective design, 20 patients received propofol at a target concentration of 3 [mu]g/ml, whereas in 20 patients propofol was titrated to maintain a BIS value of 40-50. Plasma concentrations of propofol (by means of gas chromatography-mass spectrometry), epinephrine, norepinephrine (by means of high-pressure liquid chromatography), cortisol (by means of radioimmunoassay), and interleukins 6 and 10 (by means of enzyme-linked immunosorbent assay) were measured repeatedly throughout surgery.

Results: BIS monitoring allowed a 30% reduction of propofol infusion rates and a similar decrease in plasma propofol concentrations in the BIS group without affecting the stress response to surgery for the group mean. None of the patients reported awareness during a standardized interview. Interestingly, propofol-remifentanil anesthesia blunted the release of epinephrine and cortisol to bypass surgery completely even when the propofol infusion rate was reduced according to BIS values.     

The influence of age on propofol pharmacodynamics.

BACKGROUND: The authors studied the influence of age on the pharmacodynamics of propofol, including characterization of the relation between plasma concentration and the time course of drug effect. METHODS: The authors evaluated healthy volunteers aged 25-81 yr. A bolus dose (2 mg/kg or 1 mg/kg in persons older than 65 yr) and an infusion (25, 50, 100, or 200 microg x kg(-1) x min(-1)) of the older or the new (containing EDTA) formulation of propofol were given on each of two different study days. The propofol concentration was determined in frequent arterial samples. The electroencephalogram (EEG) was used to measure drug effect. A statistical technique called semilinear canonical correlation was used to select components of the EEG power spectrum that correlated optimally with the effect-site concentration. The effect-site concentration was related to drug effect with a biphasic pharmacodynamic model. The plasma effect-site equilibration rate constant was estimated parametrically. Estimates of this rate constant were validated by comparing the predicted time of peak effect with the time of peak EEG effect. The probability of being asleep, as a function of age, was determined from steady state concentrations after 60 min of propofol infusion. RESULTS: Twenty-four volunteers completed the study. Three parameters of the biphasic pharmacodynamic model were correlated linearly with age. The plasma effect-site equilibration rate constant was 0.456 min(-1). The predicted time to peak effect after bolus injection ranging was 1.7 min. The time to peak effect assessed visually was 1.6 min (range, 1-2.4 min). The steady state observations showed increasing sensitivity to propofol in elderly patients, with C50 values for loss of consciousness of 2.35, 1.8, and 1.25 microg/ml in volunteers who were 25, 50, and 75 yr old, respectively. CONCLUSIONS: Semilinear canonical correlation defined a new measure of propofol effect on the EEG, the canonical univariate parameter for propofol. Using this parameter, propofol plasma effect-site equilibration is faster than previously reported. This fast onset was confirmed by inspection of the EEG data. Elderly patients are more sensitive to the hypnotic and EEG effects of propofol than are younger persons.     

Target-controlled infusion of propofol and remifentanil in cardiac anaesthesia: influence of age on predicted effect-site concentrations

Background. Propofol-anaesthesia administrated via target-controlledinfusion (TCI) has been proposed for cardiac surgery. Age-relatedchanges in pharmacology explain why propofol dose requirementis reduced in elderly patients. However, the Marsh pharmacokineticmodel incorporated in the Diprifusor propofol device does nottake age into account as a covariable. In the absence of depthof anaesthesia monitoring, this limitation could cause adversecardiovascular effects resulting from propofol overdose in olderpatients. We assessed the influence of age on effect-site propofolconcentrations predicted by the Diprifusor and titrated to thebispectral index score (BIS) during cardiac anaesthesia. Methods. Forty-five patients received propofol by Diprifusorand remifentanil by software including Minto model. Propofoland remifentanil effect-site concentrations were adapted toBIS (40–60) and haemodynamic profile, respectively. Theinfluence of age on effect-site concentrations was assessedby dividing patients into two groups: young (<65 yr) andelderly (     

A comparison of target- and manually controlled infusion propofol and etomidate/desflurane anesthesia in elderly patients undergoing hip fracture surgery

Elderly patients have a higher risk of developing adverse drug reactions during anesthesia, especially anesthesia affecting cardiovascular performance. In this prospective randomized study we compared quality of induction, hemodynamics, and recovery in elderly patients scheduled for hip fracture surgery and receiving either etomidate/desflurane (ETO/DES) or target-controlled (TCI) or manually controlled (MAN) propofol infusion for anesthesia. Sixteen patients were anesthetized with ETO (0.4 mg/kg) followed by DES titrated from an initial end-tidal concentration of 2.5%. Eighteen patients received propofol TCI at an initial plasma concentration of 1 microg/mL and titrated upwards by 0.5-microg/mL steps. Fifteen patients received a bolus induction of propofol 1 mg/kg over 60 s followed by an infusion initially set at 5 mg . kg(-1) . h(-1). All received a bolus (20 microg/kg) followed by an infusion of 0.4 microg . kg(-1) . min(-1) alfentanil. According to hemodynamics, concentrations of DES or propofol (TCI group) and propofol infusion rate (MAN group) were respectively adjusted by a step of 20% and 50%. In the TCI and ETO/DES groups, the time spent at a mean arterial blood pressure within 15% and 30% of baseline values was more than 60% and 80% of anesthesia time, whereas in the MAN group it was <30% and 60%, respectively. In the MAN group more anesthetic drug adjustments were recorded (6.4 +/- 2.8 versus 2.5 +/- 1.2 [ETO/DES] and 2.6 +/- 1 [TCI]). TCI improves the time course of propofol's hemodynamic effects in elderly patients.