Sufentanil Concentrations Research Articles

Effects of sufentanil on human gastric cancer cell line SGC-7901 in vitro.

Sufentanil is a new kind of opioid analgesic and acts on μ opioid receptor. In this study, we aim to investigate the effects of sufentanil on gastric cancer cell line SGC-7901, after being exposed to different concentrations of sufentanil. Gastric cancer cells were exposed to sufentanil for a predetermined time at concentrations of 0, 0.5, 5, 50 and 500 nmol/l, respectively. Cell viability at different time points after exposure to sufentanil was tested by CCK-8 assay. FDA-PI staining was used to observe membrane integrity of gastric cancer SGC7901 cells. The apoptosis of gastric cancer cells was analyzed by Annexin V-FITC/PI Flow Cytometry and the changes of the cell cycle was determined by a detection kit. As a result, cell viability decreased in a dose- and time-dependent manner. Furthermore, with the concentration of sufentanil increased, the proportion of dead and apoptotic SGC-7901 cells increased, and more cells were arrested in G2/M phase. In a word, sufentanil can inhibit the cell viability and induce the apoptosis of gastric cancer SGC-7901 cells in vitro.

Establishment of modified gas chromatography-mass spectrometry for determination of plasma sufentanil concentrations

Objective To modify gas chromatography-mass spectrometry (GC-MS) for determination of plasma sufentanil concentrations.Methods Fentanyl was used as the internal standard.The plasma samples were extracted with ethyl acetate and petroleum ether.An HP-5MS capillary column was used.The initial temperature of the column was set at 130 ℃,and the final temperature was 320 ℃.The injector port temperature was set at 290 ℃,and the interface temperature was 300 ℃.The carrier gas was high purity helium (purity 99.999％) with a constant flow rate of 1 ml/min.The injection volume was 1 μl with splitless injection.The MS conditions were as follows:EI source,ion source temperature 230 ℃,four-pole temperature 150 ℃,electron bombardment energy 70 eV,multiply voltage 2112 V,selective ion monitoring mode,solvent delay 7 min.The characteristic ions of sufentanil and fentanyl were obtained in 8.20-8.40 min and 7.60-7.80 min,respectively,according to the characteristic ion curve of sufentanil and fentanyl.Results The standard curve of sufentanil had good linear relationship in the range of 0.02-10.00 ng/ml and the equation was Y =0.1625X + 0.0316,R2 =0.9987.The extraction recovery was more than 80％,intra-day and inter-day determinations were less than 8％,and the limit of detection was 0.02 ng/ml.Conclusion When modified GC-MS is applied to determine the concentrations of sufentanil in plasma,not only the determination is sensitive and accurate,but also the procedures are simplified,and it is more suitable for the pharmacological research of sufentanil. Key words: Gas chromatography-mass spectrometry ; Sufentanil; Plasma concentration

Intranasal sufentanil/ketamine analgesia in children

The management of procedural pain in children ranges from physical restraint to pharmacological interventions. Pediatric formulations that permit accurate dosing, are accepted by children and a have a rapid onset of analgesia are lacking. To investigate a pediatric formulation of intranasal sufentanil 0.5 mcg·kg(-1) and ketamine 0.5 mg·kg(-1) for procedural pain and to characterize the pharmacokinetic (PK) profile. Fifty children (≥10 kg) scheduled for a painful procedure were included in this prospective nonrandomized open-label clinical trial. Thirteen of these children had central venous access for drug assay sampling; enabling a compartmental PK analysis using nonlinear mixed-effects models. Pain intensity before and during the procedure was measured using age-appropriate pain scales. Heart rate, oxygen saturation and sedation were recorded. Children had a mean age of 8.8 (sd 4.9) years and weight 35.2 (sd 20.1) kg. Sufentanil/ketamine nasal spray was effective (procedural pain intensity scores ≤5 (0-10)) in 78% of the painful procedures. The spray was well accepted by 94% of the children. Oxygen saturation and heart rate remained stable, and sedation was minimal. The bioavailability of sufentanil and ketamine was 24.6% and 35.8%, respectively. Maximum plasma concentration (Cmax) of sufentanil was 0.042 mcg·l(-1) (coefficient of variation (CV) 12.9%) at 13.8 min (CV 12.4%) (Tmax). Cmax for ketamine was 0.102 mg·l(-1) (CV 10.8%), and Tmax was 8.5 min (CV 17.3%). Sufentanil/ketamine nasal spray provided rapid onset of analgesia for a variety of painful procedures with few adverse effects and has promising features for use in pediatric procedural pain management.

Comparison of efficacy of patient-controlled epidural analgesia with different concentrations of sufentanil plus levobupivacaine after caesarean section

Objective To compare the efficacy of patient-controlled epidural analgesia (PCEA) with different concentrations of sufentanil plus levobupivacaine after caesarean section.Methods Ninety ASA Ⅰ or Ⅱ nulliparous patients who were at full term with a singleton fetus,aged 22-35 yr,weighing 60-85 kg,undergoing elective caesarean section under combined spinal-epidural anesthesia,were randomly divided into 3 groups (n =30each):0.125％ levobupivacaine plus sufentanil 0.4,0.6 and 0.8μg/ml groups (groups Ⅰ,Ⅱ and Ⅲ).The patients received 48 h of PCEA after operation.PCEA pump was set up with a background infusion of 2 ml/h,and a bolus dose of 2 ml with a lockout-interval of 15 min after a loading dose of 5 ml.VAS score was used to assess the intensity of pain (0 =no pain,10 =worst pain).VAS score ≤ 3 was considered as effective analgesia.VAS score ≥4 was considered as failure of analgesia,and the rescue analgesic was given.Venous blood samples were taken before operation and at 24 and 48 h after operation to detect the serum prolactin (PRL) concentration using radioimmunoassay.The degree of motor block of lower extremities was assessed and scored using modified Bromage scale.Maternal colostrum time,the number of attempts,and adverse effects including nausea and vomiting,pruritus,somnolence,respiratory depression,bradycardia,hypotension and urinary retention were recorded after operation.Results Compared with group Ⅰ,the number of attempts and rate of failure of analgesia were significantly decreased,the maternal colostrum time was shortened,and the serum PRL concentration at 24 and 48 h after operation was significantly increased in groups Ⅱ and Ⅲ,and the incidences of adverse effects such as nausea,vomiting and bradycardia were increased in group Ⅲ (P ＜ 0.05).Compared with group Ⅱ,no significant change was found in the number of attempts,rate of failure of analgesia,maternal colostrum time,and serum PRL concentration at 24 and 48 h after operation (P ＞ 0.05),and the incidences of adverse effects such as nausea,vomiting and bradycardia were increased in group Ⅲ (P ＜ 0.05).There was no significant difference in the modified Bromage scores among the three groups (P ＞ 0.05).Conclusion When sufentanil plus 0.125 ％ levobupivacaine are used for PCEA,the recommonded concentration of sufentanil is 0.6 μg/ml. Key words: Bupivacaine ; Sufentanil ; Cesarean section ; Analgesia, epidural ; Analgesia, patient-controlled

Prediction of effect-site concentration of sufentanil by dose–response target controlled infusion of sufentanil and propofol for analgesic and sedation maintenance in burn dressing changes

This study was to investigate the feasibility and efficiency of by target-controlled infusion (TCI) for analgesia and sedation during burn dressing change, and to predict the effect-site concentration of sufentanil. Eighty burn patients were randomly and evenly divided into four groups according to target sufentanil effect-site concentration (0.2, 0.3, 0.4 and 0.5ng/ml). The sufentanil–propofol TCI was carried out during dressing changes. The effect-site concentration of propofol was maintained at 1.2μg/ml. The dose–response relationships of sufentanil for providing adequate analgesia were evaluated by visual analog scales and Ramsay sedation scores. The effect-site concentration of sufentanil was calculated by Probit regression analysis. Incidence of respiratory depression, doctors and patients’ satisfaction and adverse events were assessed. The EC50 and EC95 of sufentanil to maintain anesthesia for uncovering the inner layer dressings during TCI were 0.278ng/ml (95% CI 0.231–0.318ng/ml) and 0.394ng/ml (95% CI 0.366–0.530ng/ml), respectively, while the EC50 and EC95 of sufentanil to maintain anesthesia for wound management were 0.349ng/ml (95% CI 0.299–0.366ng/ml) and 0.465ng/ml (95% CI 0.430–0.563ng/ml), respectively. Doctors and patients’ satisfaction were significantly higher in the 0.4 and 0.5ng/ml groups than the 0.2ng/ml group. One and three patients had respiratory depression in the 0.4 and 0.5ng/ml groups, respectively. No adverse events occurred after operations. In conclusion, low dose sufentanil–propofol TCI for anesthesia and sedation maintenance in burn dressing changes is feasible and effective, and wound management requires higher effect-site concentrations of sufentanil than disclosing inner layer dressings.

The optimal effect-site concentration of sufentanil for laryngeal mask insertion during induction with target-controlled propofol infusion at 4.0 μg/mL

King Fahad Hospital/Dammam University, Dept of Anaesthesiology & Intensive Care, Alkhobar, Saudi Arabia

Optimization of electromembrane extraction combined with differential pulse voltammetry using modified screen-printed electrode for the determination of sufentanil

In the present work, for the first time, electromembrane extraction (EME) combined with differential pulse voltammetry by multi-wall carbon nanotubes modified screen-printed carbon electrode has been reported for determining sufentanil. EME of sufentanil was carried out by applying a D.C. electrical potential through a thin supported liquid membrane (SLM). Charged drug molecules were extracted from an aqueous sample, through the SLM, into an acidic aqueous acceptor solution (20μL) which is placed inside the lumen of a hollow fiber. Then, the acceptor solution was analyzed using differential pulse voltammetry (DPV). A Box–behnken design was used in order to optimize different variables affecting extraction efficiency using following DPV currents as signals. The main parameters which affect the extraction and determination of sufentanil were observed to be: accumulation time, 30s; organic solvent, 2-nitrophenyl octyl ether; pH of the donor phase, 2.5; pH of the acceptor phase, 1.0; extraction time, 28min; extraction output potential difference, 190V and stirring rate, 1000rpm. Under the optimal conditions, DPV currents were linear with the concentration of sufentanil within the range of 6.4×10−8–3.62×10−6moldm−3 with the detection limit (S/N=3) of 2.0×10−8moldm−3. Finally, the proposed method has been successfully used for the determination of sufentanil in urine and plasma samples.

Median effective target effect-site concentration of sufentanil when intraoperative wake-up test was successful in patients undergoing scoliosis surgery

Objective To determine the median effective target effect-site concentration (EC50) of sufentanil when intraoperative wake-up test was successful in patients undergoing scoliosis surgery.Methods Ninety ASA Ⅰ or Ⅱ patients,aged 18-64 yr,with body mass index ＜ 30 kg/m2,scheduled for scoliosis surgery under sevoflurane and sufentanil anesthesia,were randomly divided into Ⅰ-Ⅵ groups (n =15 each).Anesthesia was induced with sufentanil,etomidate and cisatracurium,and maintained with sevoflurane,sufentanil and cisatracurium.The patients were tracheal intubated and mechanically ventilated.Before the wake-up test,infusion of cisatracurium was stopped and the end-tidal concentration of sevoflurane was adjusted to 0.The EC50 was determined by the K(a)rber method.The target effect-site concentration of sufentanil was set at 0.19 ng/ml in group Ⅰ,0.18 ng/ml in group Ⅱ and gradually decreased in decrements of 0.01 ng/ml.The wake-up test was performed 5 min later.The EC50 and 95 ％ confidence interval of sufentanil were calculated by the K(a)rber method.Results EC50 of sufentanil obtained was 0.164 ng/ml and 95％ confidence interval of sufentanil obtained was 0.157-0.172 ng/ml when the wake-up test was successful.Conclusion The EC50 of sufentanil is 0.164 ng/ml when the intraoperative wake-up test is successful in the patients undergoing scoliosis surgery. Key words: Sufentanil; Drug delivery systems; Dose-response relationship,drug

Effects of different doses of sufentanil and remifentanil combined with propofol in target-controlled infusion on stress reaction in elderly patients

The current study aimed to observe the effects of sufentanil and remifentanil combined with propofol in target-controlled infusion (TCI) on perioperative stress reaction in elderly patients. A total of 80 elderly patients requiring general anesthesia were recruited. They were divided into four groups (each n=20) according to different target concentrations of remifentanil and sufentanil. These target concentrations were: 4 ng/ml remifentanil + 0.2 ng/ml sufentanil for group I; 3 ng/ml remifentanil + 0.3 ng/ml sufentanil for group II; 2 ng/ml remifentanil + 0.5 ng/ml sufentanil for anesthesia induction and post-intubation 3 ng/ml remifentanil + 0.2 ng/ml sufentanil for anesthesia maintenance for group III; and 5 ng/ml remifentanil for anesthesia induction and post-intubation 4 ng/ml remifentanil for anesthesia maintenance for group IV. Norepinephrine (NE), epinephrine (E) and angiotensin II (Ang II) levels in plasma were measured prior to the induction of anesthesia, as well as at several different time-points following surgery. The numbers of intraoperative severe hemodynamic fluctuation, postoperative eye-opening and extubation time, and post-extubation restlessness and pain scores were recorded. Group IV had a larger circulation fluctuation control number and higher levels of NE, E and Ang II at 3 h after surgery than any other group (P<0.01). Although group IV had shorter postoperative eye-opening and extubation times compared with the other groups (P<0.05), it also had higher restlessness and pain scores (P<0.01). The combined use of sufentanil and remifentanil stabilizes perioperative hemodynamics and reduces stress hormone levels.

Comparison of effects of fentanyl, sufentanil and remifentanil on immune function of dendritic cells in human umbilical cord blood

Objective To compare the effects of fentanyl,sufentanil and remifentanil on the immune function of dendritic cells in human umbilical cord blood.Methods Human umbilical cord blood mononuclear cells were obtained by density gradient centrifugation and seeded in 24-well plates with a density of 1 × 106/ml (2ml/hole).The cells were randomly divided into 7 groups (n =15 each):control group (group C),fentanyl 1.0 ng/ml group (group F1),fentanyl 5.0 ng/ml group (group F5),sufentanil 0.1 ng/ml group (group S1),sufentanil 0.5 ng/ml group (group S5),remifentanil 1.0 ng/ml group (group R1),and remifentanil 5.0 ng/ml group (group R5).The cells were incubated for 10 days in serum-free culture medium containing 50 ng/ml recombinant human granulocyte colony stimulating factor,10 ng/ml recombinant human interleukin-4 or the corresponding concentration of fentanyl,sufentanil or remifentanil,and then 50 ng/ml recombinant human tumor necrosis factor alpha was added to the culture medium and the cells were incubated for another 4 days in the seven groups.Three holes in each group were chosen and the cell morphology was examined with inverted microscope.Six holes in each group were chosen for determination of the concentration of IL-12 in the supernatant and expression of CD80/CD86.Six holes in each group were chosen for measurement of the cell viability.Results Compared with group C,the concentration of IL-12 and cell viability were significantly decreased and the expression of CD80/CD86 was down-regulated in groups F5,S1,S5,R1 and R5 (P ＜ 0.05).The concentration of IL-12,cell viability and expression of CD80/CD86 were significantly lower in groups S1 and R1 than in group F1 (P ＜ 0.05).Compared with group F5,the concentration of IL-12 was significantly decreased in group S5,and the concentration of IL-12 and cell viability were significantly decreased and the expression of CD80/CD86 was down-regulated in group R5 (P ＜ 0.05).The concentration of IL-12 and cell viability were significantly lower in group R1 than in group S1 (P ＜ 0.05).The concentration of IL-12,cell viability and expression of CD80/CD86 were significantly lower in group R5 than in group S5 (P ＜ 0.05).Conclusion Remifentanil has stronger inhibitory effect on the immunological function of dendritic cells in human umbilical cord blood than sufentanil,and the inhibitory effect of sufentanil is stronger than that of fentanyl. Key words: Fentanyl; Sufentanil; Piperidines; Immunity, cellular; Dendritic cells

Changes in total and unbound concentrations of sufentanil during target controlled infusion for cardiac surgery with cardiopulmonary bypass

Target controlled infusion (TCI) with sufentanil is usually performed using the Gepts model, which was derived from patients undergoing general surgery. It is, however, known that pharmacokinetics of sufentanil can be changed during cardiopulmonary bypass (CPB). We tested whether TCI during coronary artery bypass surgery with CPB produces constant total, unbound sufentanil concentration-time course or both. After IRB approval, written informed consent was obtained from 38 male patients (48-74 yr) undergoing coronary artery bypass surgery. Anaesthesia was managed with propofol and TCI of sufentanil, using the Gepts model, targeting plasma concentrations of 0.4 (n=18) or 0.8 ng ml(-1) (n=20). Arterial blood samples were taken before, during, and after CPB. Total and unbound sufentanil concentrations were measured by HPLC with tandem mass spectrometry. The accuracy of the TCI model was assessed by the prediction error, and a pharmacokinetic model was determined by population analysis. The median prediction error of the TCI with the Gepts model before, during, and after CPB was 59.6, 3.9, and -10.4%, respectively. The unbound sufentanil concentrations increased significantly during CPB. Pharmacokinetic modelling showed an increase in elimination and intercompartmental clearance after initiation of CPB. Neither total nor unbound sufentanil concentrations remained constant when performing a TCI with the Gepts model in coronary artery bypass surgery with CPB. A pharmacokinetic model derived from patients undergoing cardiac surgery with CPB might improve the performance of TCI in this population.

Miniaturized hollow fibre assisted liquid‐phase microextraction and gas chromatography for determination of trace concentration of sufentanil and alfentanil in biological samples

A simple and highly sensitive method that involves miniaturized hollow fibre assisted liquid-phase microextraction with gas chromatography-flame ionization detector was developed for the determination of trace concentration of sufentanil and alfentanil in biological samples. These drugs were extracted from 5 ml of aqueous solution with pH 10.0 into an organic extracting solvent (1-octanol) impregnated in the pores and lumen of a hollow fibre. After extraction for a prescribed time, 2.0 µl of the extraction solvent was injected directly in to the GC injection port. Under the optimized conditions, (1-octanol as extracting solvent, stirring rate of 700 rpm, 15% (w/v) salt addition, pH 10.0 and 25 min sampling time at 50 °C) large enrichment factors of 535 and 420 were achieved for sufentanil and alfentanil, respectively. Dynamic linear ranges were in the range of 0.05 to 500 ng/ml for sufentanil and 0.1 to 500 ng/ml for alfentanil. Limits of detection 0.01 and 0.02 ng/ml were obtained for sufentanil and alfentanil, respectively. The percent relative intra-day and inter-day standard deviations were found to be less than 8.4% (n = 5). Finally, this method was successfully applied for the separation, preconcentration and determination of trace concentration of sufentanil and alfentanil in plasma and urine samples.

The median effective plasma concentration of propofol blunting cardiovascular responses to tracheal intubation on anesthesia induction with sufentanil in elderly patients

Objective To investigate the median effective plasma concentration (Cp50) of propofol blunting cardiovascular responses to tracheal intubation with sufentanil at different targeted concentrations on anesthesia induction in elderly patients.Methods Ninty-four patients (60 years-79 years) with an American Society of ASA physical status of Ⅰ -Ⅲ,undergoing scheduled surgery under general anesthesia were randomly allocated into one of the four groups:group A,B,C and D.The patients in group A and group B (60 years-69 years) and the ones in group C and group D(70 years-79 years) received sufentanil with a target effect concentration of 0.2 μg/L,0.3 μg/L respectively.Induction of anesthesia was initiated by targeted-controlled infusion (TCI) of sufentanil at target effect-site concentration and was maintained stable before administration of propofol,determined by up and down sequential test.At the moment of loss of consciousness,cisatracurium 0.2 mg/kg was administered and intubated after 3 min.Results The Cp50 of propofol were 3.60,2.03,2.70,1.97 mg/L with 95％ confidence interval of 3.44 mg/L-3.76 mg /L,1.88 mg/L-2.20 mg/L,2.56 mg/L-2.84 mg/L and 1.81 mg/L-2.12 mg/L in group A,B,C and D respectively. Conclusions With the concentrations of sufentanil or increased age,the Cp50 of propofol decreases in elderly patients. Key words: Propofol; Sufentanil; Targeted-controlled infusion; The median effective plasma concentration; Tracheal intubation ; The elderly

Determination of total and unbound sufentanil in human plasma by ultrafiltration and LC–MS/MS: Application to clinical pharmacokinetic study

A sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of sufentanil total and unbound drug concentrations. Unbound drug was separated by an ultrafiltration step before sample preparation. Both the ultrafiltrate and plasma samples were extracted with solid-phase extraction and substituted with deuterated sufentanil used as an internal standard. Separation was performed by gradient elution using UPLC-like system and analysed by MS/MS consisting of an electrospray ionization source. Calibration curves showed linearity in the concentration range of 5-2500 pg/ml for analysis of both total and unbound concentrations of sufentanil. The lower limit of quantification was 5 pg/ml for both total and unbound sufentanil plasma drug concentrations. Intra- and interassay precision and accuracy did not exceed 15%. Method was applied to pharmacokinetic study in patients undergoing coronary artery bypass grafting.

Effects of Three Target‐Controlled Concentrations of Sufentanil on MACBAR of Sevoflurane

Effects of Three Target‐Controlled Concentrations of Sufentanil on MAC_BAR of Sevoflurane

Low Target Sufentanil Effect-Site Concentrations Allow Early Extubation After Valve Surgery

To test the ability of low sufentanil effect-site concentrations (Ce) to shorten the time to tracheal extubation after valve surgery. A prospective, randomized, blinded, controlled study. A single university hospital. Forty-eight patients scheduled for valve surgery under target-controlled propofol infusion. After ethical committee approval, patients were allocated randomly to receive sufentanil concentrations of 0.2, 0.3, or 0.4 ng/mL (n = 16 per group) during target-controlled propofol infusion. Times to spontaneous eye opening, return of spontaneous breathing and extubation; number of changes and cumulative doses of propofol and sufentanil; incidences of light anesthesia and myocardial ischemia; intensive care unit and hospital stays; and costs of propofol, sufentanil, and ventilation were recorded. Compared with the sufentanil 0.4-ng/mL group, 0.2- and 0.3-ng/mL groups had shorter times to eye opening (24.8 min [SD 7.8] and 52.6 min [12.5] v 85.6 min [10.0], respectively), spontaneous breathing (32.7 min [19.9] and 70.1 min [27.2] v 137.5 min [20.8], respectively), and extubation (112.2 min [16.9] and 161.9 min [32.9] v 271.3 min [27.4], respectively; p < 0.001), more frequent changes in propofol concentrations (p < 0.001), higher cumulative propofol doses, lower cumulative sufentanil doses, and 33% to 44% lower total cost (p < 0.001). Incidences of light anesthesia and myocardial ischemia and intensive care unit and hospital stays were similar for all groups. Compared with sufentanil Ce of 0.4 ng/mL, lower concentrations (0.2 and 0.3 ng/mL) promoted faster recovery and shorter times to extubation after valve surgery performed under target-controlled propofol infusion.

Comparison of intraoperative wake-up test in patients undergoing scoliosis surgery with different anesthesia methods

Objective To compare the intraoperative wake-up test in patients undergoing scoliosis surgery with different anesthesia methods.Methods Forty ASA Ⅰ patients aged 13-18 yr with body mass index ＜ 30 kg/m2 scheduled for scoliosis surgery were randomly divided into 2 groups ( n =20 each): propofol combined sufentanil anesthesia group (group P) and sevoflurane combined sufentanil anesthesia group (group S).Anesthesia was induced with target-controlled infusion of sufentanil(target effect-site concentration 0.5 ng/ml),and iv injection of etomidate 0.3 mg/kg in both groups.Tracheal intubation was facilitated with 0.15 mg/kg cisatracurium when patients lost consciousness.The patients were mechanically ventilated.Anesthesia was maintained with target-controlled inhalation of sevoflurane (target end-tidal concentration 0.8％-1.5％ ) in group S,and target-controlled infusion of propofol (target plasma concentration 3-5 μg/ml) in group P,and target-controlled infusion of sufentanil (target effect-site concentration 0.2-0.3 ng/ml),and iv infusion of cisatracurium 0.1 mg· kg-1· h-1 in both groups.BIS value was maintained at 40-60.Cisatracurium administration was terminated and target effect-site concentration of sufentanil decreased to 0.1 ng/ml before wake-up test,5 min later,sevoflurane and propofol administration were terminated,and 5 min later wake-up test was performed.MAP and HR were recoreded during wake-up test.The wake-up time and advers effect (bucking,restlessness and awareness)were recorded.Results The wake-up time was significantly shorter in group S than in group P( P ＜ 0.05).MAP and HR were in normal range during wake-up test in both groups,and bucking,restlessness and awareness were not found in both groups.Conclusion Target-controlled inhalation of ssvoflurane combined with sufentanil can be safely and effectively used for intraoperative wake-up test in patients undergoing scoliosis surgery,and the wake-up time is shorter than that with propofol combined sufentanil,and it is an apporiate anesthetic technique for the intraoperative wake-up test. Key words: Anesthetics, inhalation; Drug delivery systems; Sufentanil; Scoliosis

Effect of different ages on sufentanil pharmacokinetics in patients undergoing cardiac valve replacement

Objective To assess the effect of different ages on sufentanil pharmacokinetics in patients undergoing cardiac valve replacement.Methods Sixteen NYHA Ⅱ or Ⅲ patients undergoing selective cardiac valve replacement were randomly divided into two groups:elderly group (aged 65-69 years,group Ⅰ,n =8) and young adult group (aged 36-45 years,group Ⅱ,n =8).Intravenous and intra-arterial cannulae were placed.Sufentanil 5 μg/kg injected intravenously during anesthesia induction.Blood samples from the radial artery were obtained at 1,3,5,10,20,30,60,120,180,240 and 360 min after sufentanil injection (3 ml each).Then 1 ml plasma was immediately separated from the 3 ml blood sample and stored at - 80 ℃ until being assayed.Plasma sufentanil concentration was determined with liquid chromatography mass spectrometry and pharmacokinetic parameters were calculated with 3P97 pharmacologicl program.Results Plasma sufentanil concentration versus the time decay curve in patients undergoing cardiac valve replacement before cardiopulmonary bypass (CPB) was fitted to a twocompartment model and could be expressed by bi-exponential equations:Cp (t) =27.4 e-0.41t + 3.2 e-0.029t in group Ⅰ and Cp (t) =14.4 e-0.51t +3.4 e-0.032t in group Ⅱ,respectively.There were significant differences in t 1/2 α,t1/2 β and CL between the two groups ( P ＜ 0.05 or 0.0l ).During CPB,plasma sufentanil concentration versus the time decay curve in patients undergoing cardiac valve replacement was fitted to a three-compartment model and could be expressed by tri-exponential equations:Cp(t) =22 e-0.51t + 3.5 e-0.045t + 0.21 e-0.0029 t in group Ⅰand Cp(t) =15 e-0.52t + 3.9 e-0.048t + 0.32 e-0.004t in group Ⅱ,respectively.There were no significant differences in pharmacokinetic parameters between the two groups ( P ＞ 0.05).Conclusion There are significant differences in sufentanil phannacokinetic characteristics before CPB but different ages have no obvious influence on sufentanil pharmaco-kinetics during CPB. Key words: Age factors; Sufentanil; Heart valve prosthesis; Pharmacokinetics

Half-effective target effect-site concentration of sufentanil inhibiting urethroscope insertion response when combined with propofol by target-controlled infusion in elderly patients undergoing transurethral resection of prostate

Objective To determine the half-effective target effect-site concentration (EC50 ) of sufentanil inhibiting the urethroscope insertion response when combined with propofol by target-controlled infusion (TCI) in the elderly patients undergoing transurethral resection of prostate (TURP) . Methods Twenty-two ASA Ⅰ- Ⅲ patients, aged 65 -79 yr, weighing 47-81 kg, undergoing TURP, were enrolled in the study. Anesthesia was performed with TCI of propofol and sufentanil. The target plasma concentration of propofol was 4 μg/ml. The target effect-site concentration of sufentanil was determined by up-and-down sequential trial. The initial target effect-site concentration of sufentanil was 0.3 ng/ml and the ratio of the target concentrations between the two consecutive patients was 1.1. The ECW and 95% confidence interval of sufentanil required to inhibit the response to urethroscope insertion were calculated. Results The EC50 of sufentanil required to inhibit the urethroscope insertion response was 0.23 ng/ml (95% confidence interval 0.12-0.44 ng/ml). Conclusion When combined with propofol by TCI (target plasma concentration 4 μg/ml), the EC50 of sufentanil inhibiting the response to urethroscope insertion is 0,23 ng/ml in the elderly patients undergoing TURP. Key words: Piperidines; Propofol; Dose-response relationship, drug; Drug delivery systems

Effect of sufentanil on norepinephrine-induced contraction of thoracic aorta isolated from rats with spontaneous hypertension

Objective To investigate the effect of sufentanil on norepinephrine (NE)-induced contraction of thoracic aorta isolated from rats with spontaneous hypertension (SH) .Methods Eight male rats with SH weighing 250-300 g were used in this study. The rats were decapitated and their thoracic aortas were isolated and cut into rings 2-3 mm in length. The aorta rings were suspended for isometric tension recording. The aortic rings obtained from SH rats were divided into 4 groups ( n = 8 each) : control group and 3 sufentanil groups. The contraction of aortic rings in response to NE in the absence (control) and presence of 3 concentrations of sufentanil 7 × 10-11 ,2 × 10-10 and 1 × 10-9 mol/L was recorded. Results The amplitude of NE-induced contraction of thoracic aorta was significantly greater in 3 sufentanil groups than in control group. Sufentanil significantly inhibited the NE-induced aortic contration in proportion to concentration. Conclusion Sufentanil can inhibit NE-induced contraction of thoracic aorta isolated from rats with SH in a concentration-dependent manner. Key words: Sufentanil; Norepinephrine; Hypertension; Aorta,thoracic