OBJECTIVETo observe the safety and feasibility of tracheal intubation by target-controlled infusion of propofol and remifentanil without muscle relaxant in children.

METHODSTotally 100 4-10-year-old pediatric patients (ASA1) who had been scheduled for plastic surgery were equally divided into remifentanil group and control group through computer-generated randomized grouping. In all patients, five minutes after intravenous administration of atropine 0.01 mg/kg and midazolam 0.1 mg/kg, propofol was infused at the targeted effect-site concentration (Ce of 6 μg/ml. When the intended target Ce of propofol was reached, the remifentanil group began to be infused with remifentanil at a Ce of 5 ng/ml, and normal saline (0.1 ml/kg) was injected simultaneously. In the control group remifentanil was replaced by normal saline and rocuronium (0.8 mg/kg) was injected together with the normal saline. After the equilibration of plasma and the Ce of remifentanil were reached, tracheal intubation was attempted. The complications during the induction and tracheal intubation were recorded. The intubating conditions were assessed using a five-point scoring system based on ease of laryngoscopy, vocal cords position, coughing, jaw relaxation and limb movement.

RESULTSThe success rate of tracheal intubation was in 90% in remifentanil group and 98% in the control group (P=0.122).CONCLUSION Target-controlled infusion of propofol and remifentanil at Ce of 6 μg/ml and 5 ng/ml is feasible for the induction and tracheal intubation without muscle relaxant in children.

Child ; Child, Preschool ; Female ; Humans ; Infusions, Intravenous ; Intubation, Intratracheal ; Male ; Piperidines ; administration & dosage ; Propofol ; administration & dosage

Adolescent ; Adult ; Anesthesia ; Child ; Evoked Potentials, Auditory ; Humans ; Midazolam ; pharmacology ; Monitoring, Intraoperative ; Piperidines ; administration & dosage ; Propofol ; administration & dosage ; Spine ; surgery

OBJECTIVETo observe the effects of remifentanil combined with naloxone on human sperm motility in vitro and to investigate its possible mechanism.

METHODSTwenty normal semen samples were collected, each divided into 13 aliquots, one as the control and the others treated in vitro with different concentrations of remifentanil or remifentanil + naloxone for 35 min. The percentage of progressive mobile sperm was assessed by computer-assisted sperm analysis at 5, 10, 15, 20 and 35 min.

RESULTSCompared with the control group, remifentanil at 0.1, 1, 10 and 100 microg/L significantly decreased sperm motility at 5 and 10 min in a dose-dependent manner, with no significant difference at 15 and 30 min; sperm motility showed no significant difference on 5 -35 min exposure to naloxone at 0.004 -0.04 mg/L, nor on 5, 10, 15 and 20 min exposure at 0.4 -4 mg/L, but was significantly increased at 35 min. Compared with the corresponding concentrations of remifentanil alone, remifentanil + naloxone remarkably increased sperm motility at 0.1 + 0.004, 1 + 0.04, 10 + 0.4, and 100 + 4 mg/L at 5 and 10 min, with no obvious difference at 15 and 30 min.

CONCLUSIONThe onset and offset of the effect of remifentanil on sperm motility are rapid and its inhibitory effect can be antagonized by naloxone, which may be related with the micro-opioid receptor.

Adult ; Humans ; Male ; Naloxone ; administration & dosage ; pharmacology ; Piperidines ; administration & dosage ; pharmacology ; Sperm Motility ; drug effects ; Spermatozoa ; drug effects ; Young Adult

OBJECTIVETo evaluate target-controlled infusion (TCI) of remifentail-propofol and the balanced anesthesia of fentanyl-isoflurane during the operation with suspension laryngscope.

METHODSSixty ASA I-II patients scheduled for the surgery through suspension laryngoscopy were randomly divided into two groups: TCI group and control group. In TCI group, anesthesia was maintained with TCI remifentanil-propofol which was stopped at the end of operation. The target plasma concentration of remifentanil was set at 6 microg/L and propofol at 3 mg/L. In control group, anesthesia was induced with intravenous fentanl 2.5 microg/kg and propofol 1-2 mg/kg, maintained with fentanl 0.03 microg.kg(-1). min(-1) and 1% isoflurane which was stopped at the end of surgery. Intubation was facilitated with succinylcholine 1-1.5 mg/kg.MAP, HR, ECG, S(p)O(2) and P(ET)CO(2) were monitored during anesthesia. The following parameters were recorded and compared between two groups: (1) the changes in blood pressure (BP), heart rate(HR) and S(p)O(2) at different time point; (2) recovery profile including the time of response to verbal commands, autonomous breathing, tracheal extubation, orientation recovery, discharging from PACU after operation; (3) OAAS scores after operation; (4) postoperative complications; (5) unexpected events and awareness during operation.

RESULT(1) The hemodynamics were stable while the target plasma concentration of remifentanil was set at 6 microg/L and propofol at 3 mg/L. (2) During tracheal intubation, suspension laryngoscope was inserted, and extubation MAP was significantly lower in TCI group than that in control group; (3) There were no significant differences in hemodynamic values and S(p)O(2) of different time points between two groups. Study group was faster than control group on recovery profile including the time of response to verbal commands, autonomous breathing, tracheal extubation, orientation recovery and discharging from PACU. There was respectively one unexpected event in both groups.

CONCLUSIONRemifentanil supplemented with isoflurane anesthesia can achieve the optimal hemodynamic stability during the operation with suspension laryngoscopy and better recovery profile from anesthesia than fentanyl.

Adolescent ; Adult ; Anesthetics, Combined ; administration & dosage ; Anesthetics, Intravenous ; administration & dosage ; Blood Pressure ; Female ; Heart Rate ; Humans ; Laryngoscopy ; methods ; Male ; Middle Aged ; Piperidines ; administration & dosage ; Propofol ; administration & dosage

OBJECTIVETo observe the clinical effectiveness of inductions and tracheal intubating conditions with 3% sevoflurane and different doses of remifentanil without muscle relaxant in children.

METHODSTotally 120 peadiatric patients (aged 4-10 years, American Society of Anesthesiologists grade I for inhalational induction) were randomly allocated into group I (remifentanil 1 microg/kg), group II (remifentanil 2 microg/kg), group III (remifentanil 3 microg/kg), and control group (vecuronium bromide 0.1 mg/kg). After inhalational induction with 3% sevoflurane and 60% nitrous oxide in 40% oxygen for 2 minutes, remifentanil 1 microg/kg, 2 microg/ kg, and 3 microg/kg were intravenously injected over 1 minute into patients in group I , group II, and group III, respectively. After remifentanil administration and manual ventilation for 1 minute, the trachea was intubated. In the control group, 2 minutes after intravenous administration of vecuronium bromide 0.1 mg/kg, tracheal intubation was attempted. Agitation, intubating satisfactoriness, and the circulation changes after tracheal intubation and anesthesia induction were observed.

RESULTSIn these four groups, agitation occurred in 37.5% of patients during sevoflurane induction. Satisfactory intubation rate was 70.0% in group I, 86.7% in group II, 90.0% in group III, and 93.3% in the control group. Compared with the control group, the impact of tracheal intubation on the circulatory system was smaller in group I , II , and III.

CONCLUSIONSInduction with 3% sevoflurane combined with remifentanil can be smoothly performed, followed by the successful tracheal intubation. The intubating conditions are more satisfactory with 3% sevoflurane combined with remifentanil 2 microg/kg or 3 microg/kg.

Anesthesia, Inhalation ; Anesthetics, Inhalation ; administration & dosage ; Child ; Child, Preschool ; Dose-Response Relationship, Drug ; Female ; Humans ; Intubation, Intratracheal ; adverse effects ; Male ; Methyl Ethers ; administration & dosage ; Piperidines ; administration & dosage

OBJECTIVETo observe the impacts of doxapram on anesthetic efficacy and respiratory and circulatory functions during anesthesia with remifentanil given by target-controlled infusion (TCI) combined with propofol in painless artificial abortion.

METHODSA total of 120 ASA I women requiring voluntarily painless artificial abortion were randomized into two equal groups. One group was given remifentanil by TCI at 2 ng/ml and propofol 1mg/kg (group I), and the other given remifentanil by TCI, propofol, and doxapram 0.6 mg/kg (group II). The anesthetic efficacy and respiratory and circulatory suppression during anesthesia were observed.

RESULTSBoth of the two groups showed satisfactory anesthetic efficacy with comparable the BIS values (P>0.05). No significant difference was noted in the induction time and awaking time between the two groups (P>0.05), but group I had more serious respiratory and circulatory depression than group II (P<0.05).

CONCLUSIONDoxapram may attenuate respiratory and circulatory depression during anesthesia with remifentanil given by TCI combined with propofol in painless artificial abortion, and provide comparable anesthetic efficacy.

Abortion, Induced ; Adolescent ; Adult ; Anesthetics, Combined ; Doxapram ; administration & dosage ; Female ; Humans ; Infusions, Intravenous ; Middle Aged ; Piperidines ; administration & dosage ; Propofol ; administration & dosage ; Treatment Outcome

BACKGROUNDLittle is known about the influence of liver transplantation on the pharmacokinetics of most anesthetic drugs. The goal of this study was to study the population pharmacokinetics of remifentanil in the different phases of orthotopic liver transplantation (OLT) and the influence of relevant factors.

METHODSThirteen adult patients undergoing OLT were enrolled. A single bolus infusion of remifentanil 5 microg/kg was administered during the preanhepatic, anhepatic and neohepatic phases of OLT. Arterial blood samples of 1.5 ml were collected at 0 (baseline), 1, 2, 3, 5, 7, 10, 15, 20, 25, 30, 45, 60 and 90 minutes after drug administration. Remifentanil concentration was assayed by high-performance liquid chromatography/mass spectrometry/mass spectrometry (HPLC/MS/MS). Population pharmacokinetic modeling was performed using nonlinear mixed-effects modeling (NONMEM).

RESULTSThe pharmacokinetics of remifentanil in patients undergoing OLT was best described by a two-compartment open model. The pharmacokinetic parameters were not influenced by age, gender, operative phase, blood temperature, rehydration volume, or blood loss volume during sampling. The volume of distribution in the central compartment (V(1)) and the volume of distribution in the peripheral compartment (V(2)) were influenced by body weight.

CONCLUSIONSThe population pharmacokinetics of remifentanil in patients undergoing OLT can be well described by a two-compartment open model. The functional status of the liver does not significantly affect the pharmacokinetics of remifentanil, but the body weight is an influential factor of V(1) and V(2).

Adult ; Chromatography, High Pressure Liquid ; Female ; Humans ; Liver Transplantation ; Male ; Middle Aged ; Piperidines ; administration & dosage ; pharmacokinetics ; Tandem Mass Spectrometry

OBJECTIVETo explore the impacts on EC50 in the remifentanil inhibition of tracheal intubation response by the transcutaneous electrical acupoint stimulation (TEAS) at Hegu (LI 4) and Neiguan (PC 6).

METHODSForty patients with selective surgery undergoing endotracheal intubation with intravenous general anesthesia were divided into I to II degree by the American Society of Anesthesiologists (ASA) and were randomized into an observation group and a control group, 20 cases in each one. Before general anesthesia induction, in the observation group, the transcutaneous electric stimulation was applied to bilateral Hegu (LI 4) and Neiguan (PC 6) for 30 min, with dense-disperse wave, 2 Hz/100 Hz in frequency; in the control group, the sham-stimulation was applied to the acupoints, with the lamp on, but without electric current output. Afterwards, the general anesthesia induction started. When the target concentration of propofol and remifentanil was stabilized at the preset value, the endotracheal intubation was conducted. Dixon sequential method was applied for the determination of ECs in remifentanil inhibition of tracheal intubation response.

RESULTSThe level of EC50 in remifentanil inhibition of tracheal intubation response was 3. 46 ng/mL, 95% confidence interval was 2. 80 ng/ml to 4. 27ng/mL in the observation group; those were 4. 18 ng/mL and 3. 30 ng/mL to 5. 29 ng/mL in the control group separately. The differences were significant in comparison of the two groups (P<0. 01).

CONCLUSIONTEAS apparently reduces EChe in the remifentanil inhibition of tracheal intubation response by around 17%as.

Acupuncture Points ; Adult ; Aged ; Anesthetics, Intravenous ; administration & dosage ; Female ; Humans ; Intubation, Intratracheal ; adverse effects ; Male ; Middle Aged ; Pain ; etiology ; Pain Management ; Piperidines ; administration & dosage ; Transcutaneous Electric Nerve Stimulation

OBJECTIVETo assess the value of compound anesthesia of transcutaneous electrical point stimulation and Remifentanil and the efficacy of this method on postoperative acute pain.

METHODSSixty cases with vertebral lamina internal fixation decompression operation were selected and randomly divided into 2 groups, an observation group and a control group, 30 cases in each group. The patients in the observation group received compound anesthesia of transcutaneous electrical point stimulation at Hegu (LI 4), Laogong (PC 8), Neiguan (PC 6) and Waiguan (TE 5) 30 min before anesthesia induction with HANS stimulator and then Remifentanil anesthesia. During the operation, the stimulation was lasted for 30 min and ceased for 30 min until the end of operation. The patients in the control group received simple Remifentanil anesthesia. The dosage of the narcotic, changes of both blood pressure and heart rate during operation, before and after extubation and the pain degree, etc. were investigated in the two groups.

RESULTS(1) The dosage of Isoflurane, (0.52 +/- 0.33)vol%, in the observation group was significantly lower than (1.12 +/- 0.18) vol% in the control group (P < 0.01). (2) Both blood pressure and heart rate during operation, before and after extubation in the observation group were lower than those before operation (P < 0.01), and both the blood pressure and heart rate during operation in the control group were lower than those before operation (P < 0.01). The blood pressure after extubation in the observation group was significantly lower than that of the control group (P < 0.01), and the heart rate before and after extubation in the observation group was significantly lower than that of the control group (P < 0.01). (3) The time of extubation and palinesthesia in the observation group were significantly shorter than those in the control group (P < 0.01). (4) In the observation group, the VAS scores after palinesthesia in 26 cases were < 4, and in 4 cases were > or = 5, while in the control group, the scores in 4 cases were < 4 and in 20 cases > or = 5, with a significant difference between the two groups (P < 0.01).

CONCLUSIONCompound anesthesia of transcutaneous electrical point stimulation and Remifentanil can reduce the dosage of narcotics, shorten the time of palinesthesia and effectively prevent and treat acute pain after Remifentanil anesthesia.

Acupuncture Analgesia ; Adult ; Anesthesia Recovery Period ; Anesthetics, Intravenous ; administration & dosage ; Electroacupuncture ; Female ; Humans ; Male ; Middle Aged ; Pain, Postoperative ; prevention & control ; therapy ; Piperidines ; administration & dosage ; Spine ; surgery

OBJECTIVETo explore the preventive effect of etomidate-induced myoclonus by different concentrations of target-controlled infusion of remifentanil.

METHODSA total of 120 cases undergoing general anesthesia were randomly divided into 4 groups according to different concentrations of target controlled infusion of remifentanil using plasma target controlled infusion ( Minto model) , in which the target concentration was set as 1 f.Lg/L ( group A) , 2 f.Lg/L ( group B) , 3 f.Lg/L ( group C) , and 4 f.Lg/L ( group D) . Five minutes after the balance of effect compartment, induction with etomidate 0. 3 mglkg was conducted intravenously. The intensity and duration of myoclonus was recorded.

RESULTSThe incidence of etomidate-induced myoclonus was 70.9%, 33.3%, 26.7%, and 0 in groups A, B, C, and D, respectively. Along with the increase of the remifentanil concentration, the incidence of severe myoclonus gradually reduced, which was significantly lower in group B and C than in group A ( P < 0. 05). When the concentration reached 4 f.Lg/L, bradycardia and apnea appeared.

CONCLUSIONMyoclonus induced by etomidate under general anesthesia can be prevented by target controlled infusion of remifentanil, with 2-3 f.Lg/L being the optimal concentration.

Adult ; Anesthetics, Intravenous ; administration & dosage ; adverse effects ; Etomidate ; adverse effects ; Female ; Humans ; Male ; Middle Aged ; Myoclonus ; chemically induced ; prevention & control ; Piperidines ; administration & dosage