Pharmacokinetics of sufentanil administered by target-controlled infusion in Chinese surgical patients

Background Target-controlled infusion （TCI） has been recently developed and successfully implemented in clinical practice. This study was conducted to determine the pharmacokinetics of TCI administered sufentanil in Chinese surgical patients. Methods The pharmacokinetics of sufentanil was investigated in 12 adult patients, aged 23-76 years, scheduled for prolonged surgery under general anesthesia. Anesthetic induction was carried out with propofol, rocuronium and TCI administered sufentanil aiming for target effect-site concentration of sufentanil 4 or 6 ng/ml. Sufentanil TCI lasted for 30 minutes. Frequent arterial blood samples （1.5 ml） were drawn during and up to 24 hours after sufentanil TCI. Plasma sufentanil concentrations were measured by liquid chromatography-tandem mass spectrometry; limit of sensitivity of mass spectrometry was 5 pg/ml. The data were analyzed with the nonlinear mixed-effect model program. Results The pharmacokinetics of TCI administered sufentanil were optimally described by a three-compartment model with the following parameters： the central volume of distribution （V1） = 5.4 L, the volume of distribution at steady-state （Vdss） = 195.4 L, systemic clearance （CI1） = 1.10 L/min, and elimination half-life （t1/2 Y） = 271.8 minutes. Both age and gender affected the pharmacokinetic parameters. The rapid distribution clearance （012） was negatively correlated with patient age, and the volume of slowly equilibrating compartment （V3） was positively correlated with age. The Cl2 and the volume of rapidly equilibrating compartment （V2） were influenced by gender with male patients showing higher values of Cl2 and V2 than female patients. There was no relationship of body weight, lean body mass, plasma albumin, or target effect-site concentration of sufentanil with any of the pharmacokinetic parameters studied. Conclusions The pharmacokinetics of TCI administered sufentanil in Chinese patients can be adequately described by a three-compartment model. Pharmacokinetics adjusted to the individual patient should improve the accuracy of TCI systems.     

Two-stage analysis of pharmacokinetics of sufentanil administered by target-controlled infusion in Chinese patients

Background Sufentanil is a suitable choice for target-controlled infusion （TCI） because of its shorter context-sensitive half-time. The current study was to estimate the pharmacokinetics of sufentanil TCI in Chinese patients using the two-stage analysis. Methods Twelve adult patients with American Society of Anesthesiologists （ASA） physical status I or II undergoing elective surgery under general anesthesia were included. Anesthesia was induced with propofol, rocuronium and sufentanil administered by TCI lasting for 30 minutes, with target effect-site concentration of sufentanil 4 or 6 ng/ml. Frequent arterial blood samples （1.5 ml） were taken during and up to 24 hours after sufentanil TCI. Before the end of surgery, another arterial blood sample （1.0 ml） was drawn for the blood-gas analysis. Plasma sufentanil concentrations were determined by liquid chromatography-tandem mass spectrometry （limit of quantitation was 5 pg/ml）. The data were analyzed with the two-stage approach, linear regression and correlation analysis. Results The pharmacokinetics of sufentanil TCI were adequately described by a three-compartment model. The variables were derived as follows： the volume of central compartment （V1） was 5.4 L, volume of distribution at steady-state （Vdss） was 222.6 L, metabolic clearance （CI1） was 0.84 L/min and elimination half-life （t~/2y） was 389 minutes. Patients＇ age, gender and PaCO2 correlated significantly with the pharmacokinetic parameters. The Vdss, volume of slowly equilibrating compartment （V3） and t1/2 y increased, and rapid distribution clearance （012） decreased with increasing patient age. Male patients had larger values of Vdss, volume of rapidly equilibrating compartment （V2） and V3 than female patients. The Vdss and V3 increased with higher PaCO2 values. There were no significant correlations between the pharmacokinetic variables and body weight, height, lean body mass, plasma albumin, sufentanil dose, duration of surgery, pH or base excess of blood （BE-B）. Conclusions The pharmacokinetics of sufentanil TCI in Chinese patients can be optimally described by a three-compartment model. The pharmacokinetic analysis technique may affect the pharmacokinetic parameters and correlations.     

Comparison of bolus remifentanil versus bolus fentanyl for blunting cardiovascular intubation responses in children: a randomized, double-blind study

Background The authors found no study to compare the efficacy of bolus dose fentanyl and remifentanil blunting the cardiovascular intubation response in children, so they designed this randomized, double-blind clinical study to assess the effects of remifentanil 2 μg/kg and fentanyl 2 μg/kg by bolus injection on the cardiovascular intubation response in healthy children.
Methods One hundred and two children, the American Society of Anesthesiologists （ASA） physical status 1-2 and scheduled for elective plastic surgery under general anesthesia, were randomly divided into one of two groups to receive the following treatments in a double blind manner： remifentanil 2μg/kg （Group R） and fentanyl 2 μg/kg （Group F） when anesthesia was induced with propofol and vecuronium. The orotracheal intubation was performed using a direct laryngoscope. Blood pressure （BP） and heart rate （HR） were recorded before anesthesia induction （baseline values）, immediately before intubation, at intubation and every minute for 5 minutes after intubation. The percent changes of systolic blood pressure （SBP） and HR relative to baseline values and the rate pressure product （RPP） at every observing point were calculated. The incidences of SBP and HR percent changes 〉30% of baseline values and RPP 〉22 000 during the observation were recorded.
Results There were no significant differences between groups in the demographic data, baseline values of BP and HR and the intubation time. As compared to baseline values, BP, HR and RPP at intubation and their maximum values during observation increased significantly in Group F, but they all decreased significantly in Group R. BP, HR and RPP at all observed points, and their maximum values during the observation, were significantly different between groups. There were also significant differences between groups in the percent change of SBP and HR relative to baseline values at all observed points and their maximum percent changes during the observation. The incidences of SBP and HR percent increased 〉30% of the baseline values and RPP 〉22 000 during the observation, were significantly higher in Group F than in Group R, but the incidences of SBP and HR percent decreased 〉30% of baseline values were significantly lower in Group F compared with Group R.
Conclusions When used as part of routine anesthesia induction with propofol and vecuronium in children, fentanyl 2 μg/kg by bolus injection fails to effectively depress the cardiovascular intubation response. Remifentanil 2 μg/kg by bolus injection can completely abolish the cardiovascular intubation response, but also cause more adverse complications of temporary siclnificant cardiovascular depression.     

对老年患者采用手控或靶控输注丙泊酚的对比观察

目的 观察靶控输注方式对老年患者麻醉剂用量、血流动力学和苏醒等方面的影响.方法 2009年4月至2010年2月于北京大学第三医院行腹腔镜结直肠癌手术的65岁以上患者60例,经过医院伦理委员会的批准,根据随机数字表将患者随机分为手控输注(MCI组,n=30例)和靶控输注(TCI组,n=30例).麻醉诱导,MCI组丙泊酚输注速度为200 ml/h,TCI组初始丙泊酚血浆浓度2.0μg/ml,逐渐增加靶浓度,至患者意识消失.两组瑞芬太尼输注方案相同.气管插管后根据脑电双频指数(BIS)调整丙泊酚输注速度或靶浓度,根据血流动力学参数变化调整瑞芬太尼输注速度.记录患者意识消失时间、插管时间、诱导和维持阶段丙泊酚和瑞芬太尼用量、血压、心率、调整泵速或靶浓度的次数及苏醒时间.结果 两组患者意识消失时间、插管时间、意识消失时丙泊酚用量、维持期丙泊酚用量、插管前及维持期间瑞芬太尼用量的差异无统计学意义,在维持过程中TCI调整靶浓度的次数明显低于MCI组调整输注速度的次数[(5.8±2.1)vs(7.8±3.7)次,P＜0.01].两组患者BIS值、血压、心率的变化、血管活性药的应用、苏醒时间的差异无统计学意义.结论 虽然靶控输注系统操作简单,维持过程中调整次数少,但在老年人采用靶控输注在诱导和维持期丙泊酚用量、维持血流动力学和麻醉深度的稳定性、以及术后苏醒等方面,无明显优势.

Abstract：

Objective To evaluate the impact of anesthesia via target-controlled infusion (TCI) on drug consumption, intraoperative hemodynamic stability and recovery compared with manual-controlled infusion (MCI) in elderly patients. Methods Under the approval of the hospital ethics committee, 60elderly patients undergoing laparoscopic surgery were randomly allocated by random numbers to either the MCI group (n =30) or the TCI group (n =30). The patients in MCI group received an infusion of propofol at 200 ml/h while those in TCI group propofol at an initial plasma concentration of 2.0μg/ml and titrated upwards by 0.5μg/ml steps until loss of consciousness. Both groups received an infusion of remifentanil.After intubation, the infusion rate or the target concentration of propofol was titrated to maintain BIS (bispectral index) values between 40 and 60. The infusion of remifentanil was adapted to intraoperative hemodynamics. The doses of propofol and remifentanil were recorded, the hemodynamic parameters and the use of vasoactive drugs collected and the recovery times assessed. Results The time of loss of consciousness and the time to intubation, the doses of propofol and remifentanil during induction and maintenance were not significantly different between two groups. The times of pump adjustment were less in TCI group versus MCI group [(5.8±2.1)vs(7.8±3.7) times, P＜0.01]. Blood pressure and heart rates were not statistically different at any time point between two groups. There were no significant differences in BIS or the use of vasoactive drugs between two groups. The recovery times were similar for two groups. Conclusion Although target infusion system is easy to use and requires less time of adjustment, it fails to show added benefit on propofol consumption, hemodynamic stability, anesthesia depth and recovery in elderly patients.     

Anesthesia

<正>209319 Effects of different doses of sufentanil combined with target controlled infusion of propofol on hemodynamics in patients during anesthesia induction:a prospective,multicenter,randomized,doubleblinded study/Zhu Minmin(朱敏敏,Dept Anesthesiol,Nanjing Gen Hosp,Nanjing Mil Command,Nanjing 210002)…∥Chin J Anesthesiol.-2009,29(4).-293～295Objective To investigate the effects of different doses of sufentanil combined with target controlled infusion(TCI) of propofol on hemodynamics in patients during anesthesia induction and the appropriate dose of sufentanil.Methods This was a prospective,multicenter,randomized,double-blinded clinical trial.One hundred and sixty-five patients of both sexes,ASA Ⅰ or Ⅱ,aged 18-63 yr,weighing 42-90 kg,scheduled for elective abdominal surgery,were divided into 4 groups according to the different induction doses of sufentanil:sufentanil 0.4 μg/kg group(group S1,n=44),0.6 μg/kg group(group S2,n=43),0.8 μg/kg group(group S3,n=38) and 1 μg/kg group (group S4,n=40).Anesthesia was induced with iv injection of midazolam 0.05 mg/kg,TCI of propofol (target plasma concentration set at 3.0 μg/ml) and iv injection of sufentanil 0.4,0.6,0.8 and 1 μg/kg.Tracheal intubation was facilitated with rocuronium 0.9 mg/kg.The patients were mechanically ventilated (BIS at 35-45).Systolic pressure(SP),diastolic pressure (DP),MAP and HR were recorded before induction of anaesthesia(T0),at the time of propofol achieving the target plasma concentration of 3.0 μg/ml(T1),at 1 min(T2) and 3 min (T3) after injection of sufentanil,and immediately (T4) and at 1 min(T5),3 min(T6) and 5 min (T7) after tracheal intubation.The adverse cardiovascular events including bradycardia,tachycardia,hypertension and hypotension,and hemodynamic responses to intubation were also recorded.Results There were no significant differences in the incidence of hypotension,hypertension and techycardia during anesthesia induction between 4 groups.The incidence of bradycardia at T4-7 was significantly highe     

Clinical evaluation of target controlled infusion system for sufentanil administration

Background Sufentanil target controlled infusion （TCI） provides stable analgesia, better hemodynamic control than a bolus injection of intravenous anesthetics, anticipated recovery and improved quality of anesthesia during perioperative period. This study evaluated the accuracy and feasibility of TCI system for sufentanil at high concentrations in Chinese surgical patients. Methods Twelve low risk adult patients undergoing elective surgery under general anesthesia were included in this study. Sufentanil was administered with a specific TCI system incorporating the population pharmacokinetic data of sufentanil previously reported, using a target effect-site concentration of sufentanil 4 or 6 ng/ml. Sufentanil TCI duration was 30 minutes. Frequent arterial blood samples were taken during and up to 24 hours after sufentanil TCI for determination of plasma sufentanil concentrations by liquid chromatography-mass spectrometry/mass spectrometry. The changes of circulatory system function during the procedure, recovery profile and adverse effects were recorded. Measured plasma sufentanil concentrations were compared with the values predicted by the TCI system. The bias （median performance error, MDPE）, precision （median absolute performance error, MDAPE） and wobble （variability of performance error） of the sufentanil TCI system were determined. Results All patients had stable cardiovascular variables during induction and maintenance of anesthesia. Time to eye opening and extubation were （5.6±1.7） minutes when TCI set to 4 ng/ml and （7.2±2.3） minutes when set to 6 ng/ml. There was no episode of agitation, muscle rigidity or intraoperative awareness. The bias （MDPE）, precision （MDAPE） and wobble of the sufentanil TCI system were -3.7%, 18.9% and 19.6% respectively during TCI, and the MDPE, MDAPE and wobble were -29.1%, 31.7% and 15.0% respectively after TCI （up to 8 hours）. Conclusions The TCI system programmed for sufentanil at 4 or 6 ng/ml was considered acceptable for clinical use in low risk Chinese surgical patients. But the relatively larger MDPE and MDAPE after TCI suggest improvements of the Dharmacokinetic model are needed.     

Comparison of the ability of wavelet index and bispectral index for reflecting regain of consciousness in patients undergone surgery

Background Wavelet index （WLI） is a new parameter for monitoring depth of anesthesia based on Wavelet analysis. We observed the change of WLI and bispectral index （BIS） in patients regain of consciousness （ROC） in the absence of frontalis electromyographic （EMG） interference. The aim of this study was to compare the ability of WLI and BIS for reflecting ROC in patients undergone surgery. Methods Twelve patients who were scheduled for maxillofacial surgeries were enrolled in the study. BIS and WLI values were monitored continually. After being given midazolam and remifentanil, patients were asked to squeeze the investigator＇s hand ever 30 seconds. Patients were continuously given propofol until loss of consciousness （LOC1）. Tunstalrs isolated forearm technique was used to test the surgical consciousness in patients. After total muscle relaxation endotracheal intubations were performed, and the patients were connected to a ventilator. Then, propofol was withdrawn until the patients showed regain of consciousness （ROC1） and an awareness reaction. After the command test, patients were readministered with propofol until loss of consciousness （LOC2）. After surgery, all of the sedatives were withdrawn, and the patients were let to regain consciousness （ROC2）, Results The BIS values of twelve patients at ROC1 after using muscle relaxant were much lower than those at LOC1 and ROC2 without using muscle relaxant, showing statistical significance （P 〈0.05）. Meanwhile, the WLI values of twelve patients at ROC1 after using muscle relaxant were much higher than those at LOC1 and equal to ROC2 without using muscle relaxant, showing statistical significances （P 〈0.05） between ROC1 and LOCI. Conclusions This study showed that under muscle relaxation or facial paralysis, when there is no EMG signal, BIS can not accurately reflect regain of consciousness in surgical patients, but WLI can reflect it accurately. So WLI may have advantages for reflecting state of consciousness in surgical patients.     

Concentrations of propofol in cerebral spinal fluid: target-controlled infusion

Background Although the performance of target-controlled infusion (TCI) have been studied extensively, the accuracy and safety of a TCI system that targets the effect site remains to be demonstrated. This study was to investigate the relations of TCI of propofol to its concentrations in cerebral spinal fluid (CSF), the effect-site concentrations and bispectral index (BIS).Methods Twelve mongrel dogs were used for investigations. The target effect-site concentration was set at 3 μg/ml and the infusion was lasted for 15 minutes. CSF and blood samples were then collected and propofol concentrations were determined by using high performance liquid chromatography with fluorescence detection. BIS and hemodynamic data were monitored continuously.Results The predicted plasma concentrations were generally overestimated. Median performance error (MDPE) and absolute median performance error (MDAPE) were -10.0% and 29. 9% respectively. Propofol CSF concentrations were much lower than its effect-site concentrations.Changes in BIS were consistent with propofol concentrations in CSF, both of which changed direction at 5 minutes while the effect-site concentrations relatively lagged behind. Better correlation (r^2 =0. 9195) was found between BIS and CSF concentrations, when compared with that between BIS and effect-site concentrations ( r^2 =0. 554).Conclusion With 1% enflurane inhaled, the inconsistency of drug effect to the effect-site concentrations may result from inaccuracy of pharmacokinetic parameters. CSF may show effect-site concentrations more accurately than plasma when using target effect-site concentration infusion.     

Evaluation of entropy for monitoring the depth of anesthesia compared with bispectral index: a multicenter clinical trial

Background  As a new electroencephalogram (EEG) signal processing technique for monitoring the depth of anesthesia, entropy consists of two indices: reaction entropy (RE) and state entropy (SE). Our study compared entropy with classical bispectral index (BIS) in reduction of myoelectrical interference and noxious stimuli with EEG signals.

Methods  Two hundred and eighty patients (ASA I–II, 18–60 years old) undergoing scheduled surgeries from seven medical centers were enrolled. Anesthesia induction was managed with propofol via the target-controlled infusion (TCI) system. The results of BIS, RE, SE, mean arterial pressure (MAP) and heart rate (HR) were recorded before anesthesia induction, at the moment of unconsciousness, before and 2 minutes after administration of muscle relaxant, and before and one and three minutes after the tracheal intubation.

Results  The values of half maximum effective concentrations (EC50), 5% effective concentrations (EC05) and 95% effective concentrations (EC95) of propofol effect-site concentration at the onset of unconsciousness were 1.2 (1.1–1.3 μg/ml), 2.5 (2.4–2.5 μg/ml) and 3.7 (3.7–3.8 μg/ml), while those of the predicted plasma propofol concentration were 2.8 (2.7–2.9 μg/ml), 3.9 (3.8–3.9 μg/ml) and 4.9 (4.8–5.0 μg/ml), respectively. The values of BIS, SE and RE were 62, 59 and 63 when 50% of patients lost consciousness, and 79, 80, 85 and 42, 37, 44, respectively, when 5% and 95% of patients were unconscious. The values of BIS, RE and SE dropped two minutes after the injection of muscle relaxant, but there were no significant differences between RE and SE. MAP and HR increased visibly, which indicated a reaction to tracheal intubation; the values of BIS, RE and SE, however, did not display any significant changes.

Conclusions  This large-sample multicentric study confirmed the values of RE and SE as approximating BIS value, at the onset of unconsciousness during propofol TCI anesthesia. After elimination of myoelectrical activation, all values of RE, SE and BIS decreased significantly and the three indices were less sensitive to noxious stimuli than cardiovascular responses.

     

Diagnostic utility of N-terminal-proBNP in differentiating acute pulmonary embolism from heart failure in patients with acute dyspnea

Background The plasma N-terminal pro-B-type natriuretic peptide （NT-proBNP） level is frequently elevated in dyspnoeic patients and increasingly used in emergency departments to assess the cause of acute dyspnea.In this study we prospectively tested NT-proBNP levels in patients with congestive heart failure （CHF） and/or acute pulmonary embolism （APE） and determined the utility of NT-proBNP for discriminating APE from CHF.Methods A cohort of 177 dyspnoeic patients with a diagnosis of APE and/or CHF was prospectively studied between June 2010 and March 2013.NT-proBNP was measured by the electrochemiluminescence immunoassay （ECLIA）.All patients were evaluated with transthoracic echocardiography （TTE）.APE was diagnosed in the presence of thrombi signs in the pulmonary arteries with computed tomographic pulmonary angiography （CTPA） or a high-probability lung ventilation/ perfusion scan.Risk stratification was based on the evaluation on admission according to the ESC guidelines from 2008.The diagnosis of CHF was based on the guidelines of the American College of Cardiology/American Heart Association and the European Society of Cardiology.Two physicians independently reviewed the records to determine the final diagnosis.Results Fifty-nine patients met the criteria for dyspnea caused by APE,and 113 patients were diagnosed with CHF.Most of the APE patients （41,69.5%） were intermediate-risk.The symptoms and signs,such as orthopnea,paroxysmal nocturnal dyspnea and rales in the lungs,were more common in patients with CHF than in patients with APE （P 〈0.01）.Median NT-proBNP was significantly lower in patients with APE compared to those in patients with CHF （2 855.9 pg/ml vs.6 911.4 pg/ml,P 〈0.01）.We constructed the receiver operating characteristics （ROC） curve in predicting the diagnosis of APE.At a cut point=1 582.750 pg/ml,NT-proBNP provided a specificity of 93% and a true positive rate （sensitivity） of 17% for the diagnosis.At a cut point=3 390.000 pg/ml,NT-proBNP had a speci     

靶控输注不同浓度舒芬太尼对丙泊酚TCI镇静催眠的影响

目的在麻醉诱导期观察靶控输注（TCI）不同浓度舒芬太尼对丙泊酚镇静催眠效应的影响。方法 60例择期手术全麻患者,年龄25～60岁,ASAⅠ～Ⅱ级。随机分为4组,每组15例。A组为单纯丙泊酚组;B、C、D组为丙泊酚＋舒芬太尼组,舒芬太尼的靶效应浓度分别为0.1、0.2、0.3ng/ml。B、C、D组在TCI舒芬太尼达平衡后,TCI丙泊酚。记录舒芬太尼达平衡后1min和丙泊酚效应浓度达1.0、1.5、2.0、2.5、3.0μg/ml时的脑电双频谱指数（BIS）和OAA/S评分。结果在单纯输注舒芬太尼期间,BIS和OAA/S评分无明显变化;随丙泊酚浓度升高,患者BIS和OAA/S评分逐渐下降;相同丙泊酚浓度时,各组间的BIS值无明显差别;丙泊酚浓度为1.0、1.5、2.0μg/ml时,D组的OAA/S评分（4.1±0.3、4.3±0.7、3.1±1.1）明显低于A组（4.1±0.7、3.1±1.3、2.1±1.0,P〈0.05）。结论麻醉诱导期间输注0.1ng/ml和0.2ng/ml浓度的舒芬太尼不增强丙泊酚的镇静催眠效应,0.3ng/ml的舒芬太尼可以增加丙泊酚的镇静催眠效应。     

靶控输注不同浓度丙泊酚诱导重症肌无力患者气管插管时舒芬太尼的半数有效浓度

目的研究靶控输注（TCI）不同浓度丙泊酚复合气管内表面麻醉,在无肌松药下诱导重症肌无力患者气管插管所需舒芬太尼的半数有效浓度及两药复合的相互作用。方法拟行经胸骨正中劈开胸腺切除术的重症肌无力患者40例,ASA Ⅰ或Ⅱ级（I型6例,Ⅱa型8例,Ⅱb型20例,Ⅲ型2例,Ⅳ型4例）。按丙泊酚血浆靶浓度（Cp）不同分A、B两组,每组20例。A组丙泊酚Cp维持3.5μg/ml不变,B组Cp维持4μg/ml不变;舒芬太尼采用效应室浓度（Ce）靶控输注,按序贯法确定浓度,依次为0.1、0.15、0.23、0.34、0.5ng/ml等比递增,相邻效应室靶浓度之间比例为1.5。复合气管内表面麻醉后行气管插管。监测诱导时、插管过程中的血压、心率和脑电双频指数（BIS）。序贯法进行诱导,即前1例患者若在置入喉镜、喉麻管及插管时无体动呛咳,则下1例患者接受的药物降低1个浓度;若在任何一个环节患者有体动或呛咳,则下1例患者接受的药物提高1个浓度。结果丙泊酚为3.5μg/ml时,50%患者完成插管时舒芬太尼的浓度为0.23ng/ml,95%可信区间为（0.20～0.27）ng/ml。丙泊酚为4μg/ml时,50%患者完成插管时舒芬太尼的浓度为0.22ng/ml,95%可信区间为（0.17～0.28）ng/ml。结论在不使用肌松药并复合气管内表面麻醉的情况下完成气管插管,丙泊酚血浆靶浓度分别为3.5μg/ml和4μg/ml时,舒芬太尼半数有效效应室靶浓度为0.23ng/ml和0.22ng/ml,两药复合有协同作用。     

状态熵指数与靶控输注异丙酚时镇静深度及预测效应部位浓度的关系

目的：探讨状态熵指数(SE）与靶控输注异丙酚麻醉不同镇静深度及预测效应部位浓度的关系,并与BIS进行比较。方法：择期全麻患者20例,靶控输注异丙酚初始靶浓度为1.0μg/ml,预测效应部位浓度达到设定浓度后1min以0.5μg/ml的浓度梯度递增,目标镇静深度为警觉/镇静（OAA/S）评分1分。结果：SE、BIS与OAA/S评分相关系数分别为0.82（P＜0.01）和0.73（P＜0.01）; SE、BIS与预测效应部位浓度之间相关系数分别为-0.66（P＜0.01）和-0.70（P＜0.01）,50%和90%患者意识消失时的预测效应部位浓度分别为3.55（3.17,4.61）μg/ml和4.83（4.07,7.00）μg/ml。结论：状态熵指数与靶控输注异丙酚时的不同镇静深度以及预测效应部位药物浓度具有良好的相关性。     

咪达唑仑靶控输注期间BIS对不同年龄结肠癌患者意识状态的预测

目的探讨咪达唑仑靶控输注（TCI）期间脑电双频谱指数（BIS）对结肠癌患者意识状态变化的预测及不同年龄对其的影响。方法回顾性分析我院2004年2月~2010年2月收治入院的采用硬膜外麻醉下行结肠癌手术患者40例临床资料,按照年龄不同进行分组,年轻组（40~64岁,A组）和老年组（65~85岁,B组）,每组20例,按咪达唑仑效应室靶浓度（Ce）分阶段实施TCI,采用警觉/镇静（OAA/S）评分评价意识状态变化。记录每次评分前即刻的BIS值及血流动力学指标,分析BIS预测镇静深度的概率（Pk）,通过Pk评价BIS对意识状态的预测效果。结果随着咪达唑仑Ce增加,两组患者BIS逐渐降低,两组总体变化趋势一致。患者意识消失时,BIS值：A组为（61.6±7.9）,B组为（72.9±5.9）。Ce：A组为（69.8±8.9）μg/L,B组为（53.3±9.4）μg/L。同一镇静评分（OAA/S4~1）时,B组的BIS值明显高于A组（P〈0.01）。两组BIS对于意识消失的预测概率（Pk）：A组为（0.883±0.034）,B组为（0.819±0.028）,两组间比较差异无统计学意义（P〉0.05）;TCI期间两组心率和脉搏血氧饱和度无明显改变。与基础值比较,当OAA/S评分降至2分以下时,血压下降（P〈0.05）。结论咪达唑仑TCI期间,BIS能预测意识状态的变化,且对年轻患者和老年患者的预测相当。     

瑞芬太尼联合异丙酚双通道靶控输注用于心功能Ⅱ～Ⅲ级老年患者的全麻诱导

目的探讨瑞芬太尼复合异丙酚靶控输注(TCI)全凭静脉麻醉用于心功能Ⅱ～Ⅲ级老年患者全麻诱导的合适效应室靶浓度。方法全麻下心功能Ⅱ～Ⅲ级年龄62～86岁患者择期手术病人60例,随机分为3组,每组20例。入室后(基础值T1)静脉输注乳酸钠林格氏液5ml/kg,效应室靶浓度TCI(T2)3组病人瑞芬太尼从1.0ng/ml分别渐升至2.0ng/ml,3.0ng/ml和4.0ng/ml(T3)后启动异丙酚TCI,从1.0μg/ml血浆靶浓度渐升至4.0μg/ml(T4),气管插管后即刻(T5),气管插管后2min(T6)。记录平均动脉压(MAP)、心率(HR)、双频谱指数(BIS),不良反应发生率、辅助药物使用次数。结果与Ⅰ组比较,Ⅱ组Ⅲ组给药后气管插管时及气管插管后MAP、HR降低(P<0.05),而Ⅱ组、Ⅲ组不良反应次数较Ⅰ组多、麻醉过浅次数较Ⅰ组少(P<0.05),而BISⅠ组较高。结论瑞芬太尼复合异丙酚TCI全凭静脉麻醉用于老年心功能Ⅱ～Ⅲ级患者全麻诱导效应室靶浓度TCI瑞芬太尼宜为3.0ng/ml复合异丙酚TCI4.0μg/ml。     

丙泊酚联合舒芬太尼靶控输注用于冠脉搭桥手术的探讨

目的观察不同浓度舒芬太尼联合丙泊酚靶控输注（TCI）用于冠脉搭桥手术的最佳剂量选择。方法选择行冠脉搭桥手术患者36例（ASAⅠ～Ⅲ级）,随机分为A、B、C 3组,每组12例,分别靶控输注舒芬太尼0.5,1.0,1.5μg/L和丙泊酚0.5～2.0 mg/L,使脑电双频指数（BIS）保持在40～60范围内。劈胸骨后舒芬太尼靶浓度减少1/4。观察3组患者MAP、HR和丙泊酚用量的变化以及丙泊酚Ce改变的次数。结果相对于诱导前（T1）,A组患者在劈胸骨时HR和MAP值（T4）显著升高（P〈0.05）;相对于A组,C组在插管时（T3）MAP值显著下降（P〈0.05）,B组和C组在劈胸骨时HR和MAP值显著降低（P〈0.05）。B组和C组的丙泊酚用量和丙泊酚Ce改变次数显著少于A组（P〈0.05）。结论靶控输注高浓度舒芬太尼（舒芬太尼靶浓度≥1.0μg/L）联合丙泊酚用于冠脉搭桥手术,血流动力学更稳定,并能减少丙泊酚的用量和丙泊酚Ce改变次数。     

Comparison of C50 for Propofol-remifentanil Target-controlled Infusion and Bispectral Index at Loss of Consciousness and Response to Painful Stimulus in Elderly and Young Patients

Background:In this prospective randomized study,we compared the predicted blood and effect-site C50 for propofol and remifentanil target-controlled infusion (TCI) and the bispectral index (BIS) values ...     

老年患者全麻诱导期丙泊酚和瑞芬太尼联合靶控输注的最佳复合浓度

 目的 探讨老年患者全麻诱导期丙泊酚和瑞芬太尼联合靶控输注的最佳复合浓度。方法 将50名年龄在65~75岁之间的患者随机分为5组：A、B、C、D、E组,瑞芬太尼效应室浓度分别设为:0、2、4、6、8 ng/mL。丙泊酚效应室药物浓度由2 μg/mL开始,每2 min追加1 μg/mL至脑电双频指数（bispectral index,BIS）稳定于（40±5）。监测诱导期间不同时间点瑞芬太尼血浆和效应室浓度、丙泊酚血浆和效应室浓度、心率、有创血压、BIS、听觉诱发电位和体动反应,经统计分析,进行最佳复合浓度判断。结果 诱导期间,各组间高血压和低血压发生比例具有显著性差异（P<0.05）,B组血流动力学最平稳,分别为20%和10%。意识消失时,丙泊酚和瑞芬太尼效应浓度存在负相关性。气管插管即刻,B组体动反应和血流动力学变化最小。结论 瑞芬太尼复合丙泊酚联合靶控输注可安全用于老年患者全麻诱导,瑞芬太尼效应室浓度为2 ng/mL时血流动力学最平稳：意识消失时,丙泊酚效应室浓度为（3.5±0.8）μg/mL;气管插管时,丙泊酚效应室浓度为5.3 μg/mL。     

无肌松药下表面麻醉复合异丙酚靶控输注诱导病人气管插管的可行性

目的：探讨无肌松药下表面麻醉复合异丙酚靶控输注诱导病人气管插管的可行性。方法：拟行气管插管全身麻醉的手术病人40例，年龄20～60岁，ASAI或Ⅱ级，诱导前静脉注射芬太尼1μg/kg，以异丙酚效应室靶浓度4μg/ml行麻醉诱导，插管时用2%利多卡因4～5ml行气管黏膜表面麻醉。监测诱导、插管过程中的血压、心率和脑电双频指数（BIS）。插管时按面罩通气难易、下颌松弛度、声带位置高低、置入喉镜难易、是否有咳嗽体动以及对套囊充气反应等方面对插管条件进行评价。结果：与插管前即刻比较，插管后即刻心率加快，插管后即刻及插管后1min血压升高（P〈0.01）。插管前后的BIS值比较差异无统计学意义（P〉0.05）。所有病人均一次插管成功。插管条件综合评价的满意率为90%。结论：无肌松药下用2%利多卡因4～5ml行气管黏膜表面麻醉复合异丙酚4μg/ml效应室浓度靶控输注诱导病人气管插管时，可提供良好的气管插管条件。