Methods: Forty intent-to-treat patients were randomly allocated to receive a blinded infusion of either remifentanil 0.15 [mu]g[middle dot]kg-1[middle dot]min-1 or morphine 0.75 [mu]g[middle dot]kg-1[middle dot]min-1. The opioid infusion was titrated, in the first intent, to achieve optimal sedation defined as Sedation Agitation scale of 4. A midazolam open-label infusion was started if additional sedation was required.
Results: The mean percentage hours of optimal sedation was significantly longer in the remifentanil group (78.3 +/- 6.2) than in the morphine group (66.5 +/- 8.5). This was achieved with less frequent infusion rate adjustments (0.34 +/- 0.25 changes/h) than in the morphine group (0.42 +/- 0.22 changes/h). The mean duration of mechanical ventilation and extubation time were significantly longer in the morphine group (18.1 +/- 3.4 h, 73 +/- 7 min) than in the remifentanil group (14.1 +/- 2.8 h, 17 +/- 6 min), respectively. Remifentanil mean infusion rate was 0.13 +/- 0.03 [mu]g[middle dot]kg-1[middle dot]min-1, whereas morphine mean infusion rate was 0.68 +/- 0.28 [mu]g[middle dot]kg-1[middle dot]min-1. More subjects in the morphine group (9 of 20) than in the remifentanil group (6 of 20) required midazolam. The incidence of adverse events was low and comparable across the two treatment groups. 相似文献
Methods: Seventy-five patients undergoing major abdominal surgery were randomly assigned to receive (1) intraoperative remifentanil at 0.05 [mu]g [middle dot]kg-1 [middle dot]min-1 (small-dose remifentanil); (2) intraoperative remifentanil at 0.40 [mu]g [middle dot]kg-1 [middle dot]min-1 (large-dose remifentanil); or (3) intraoperative remifentanil at 0.40 [mu]g [middle dot]kg-1 [middle dot]min-1 and 0.5 mg/kg ketamine just after the induction, followed by an intraoperative infusion of 5 [mu]g [middle dot] kg-1 [middle dot] min-1 until skin closure and then 2 [mu]g [middle dot]kg-1 [middle dot]min-1 for 48 h (large-dose remifentanil-ketamine). Pain scores and morphine consumption were recorded for 48 postoperative hours. Quantitative sensory tests, peak expiratory flow measures, and cognitive tests were performed at 24 and 48 h.
Results: Hyperalgesia to von Frey hair stimulation adjacent to the surgical wound and morphine requirements were larger (P < 0.05) and allodynia to von Frey hair stimulation was greater (P < 0.01) in the large-dose remifentanil group compared with the other two groups, which were comparable. There were no significant differences in pain, pressure pain detection threshold with an algometer, peak flow, cognitive tests, or side effects. 相似文献
Methods: Thirty-two women were assigned randomly to one of two drug treatment groups. After premedication with 0.04 mg/kg intravenous midazolam, anesthesia was induced with 2 [micro sign]g/kg intravenous fentanyl, 1.5 mg/kg intravenous propofol, and 0.6 mg/kg intravenous rocuronium, and maintained with desflurane, 2%, and nitrous oxide, 65%, in oxygen. Before skin incision, an infusion of either remifentanil (0.02 [micro sign]g [middle dot] kg-1 [middle dot] min-1) or adenosine (25 [micro sign]g [middle dot] kg-1 [middle dot] min-1) was started and subsequently titrated to maintain systolic blood pressure, heart rate, or both within 10-15% of the preincision values.
Results: Adenosine and remifentanil infusions were effective anesthetic adjuvants during lower abdominal surgery. Use of adenosine (mean +/- SEM, 166 +/- 17 [micro sign]g [middle dot] kg-1 [middle dot] min-1) was associated with a significantly greater decrease in systolic blood pressure and higher heart rate values compared with remifentanil (mean +/- SEM, 0.2 +/- 0.03 [micro sign]g [middle dot] kg-1 [middle dot] min-1). Total postoperative opioid analgesic use was 45% and 27% lower in the adenosine group at 0-2 h and 2-24 h after surgery, respectively. 相似文献
Methods: Forty-one adults (aged 20-60 yr) and 24 children (aged 2-10 yr) undergoing lower abdominal surgery were studied. In adults, anesthesia induction was with sevoflurane during remifentanil infusion, whereas in children remifentanil administration was started after induction with sevoflurane. After intubation, sevoflurane was administered in 100% O2 and was adjusted to an ET% of 1 MAC-awake corrected for age at least 15 min before surgery. Patients were randomized to receive remifentanil at a rate ranging from 0.05 to 0.35 [mu]g [middle dot] kg-1 [middle dot] min-1 for at least 20 min before surgery. At the beginning of surgery, only the skin incision was performed, and the somatic and autonomic responses were observed. The somatic response was defined as positive with any gross movement of extremity, and the autonomic response was deemed positive with any increase in heart rate or mean arterial pressure equal to or more than 10% of preincision values. Using logistic regression, the IR50 and IRBAR50 were determined in both groups of patients and compared with unpaired Student t test. A P value less than 0.05 was considered significant.
Results: The IR50 +/- SD was 0.10 +/- 0.02 [mu]g [middle dot] kg-1 [middle dot] min-1 in adults and 0.22 +/- 0.03 [mu]g [middle dot] kg-1 [middle dot] min-1 in children (P < 0.001). The IRBAR50 +/- SD was 0.11 +/- 0.02 [mu]g [middle dot] kg-1 [middle dot] min-1 in adults and 0.27 +/- 0.06 [mu]g [middle dot] kg-1 [middle dot] min-1 in children (P < 0.001). 相似文献
Methods: Forty consenting patients (classified as American Society of Anesthesiologists physical status I-III) scheduled for microlaryngoscopy were randomized to receive, in a double-blind manner, either remifentanil (loading dose 1 [mu]g/kg; maintenance infusion, 0.25 [mu]g [middle dot] kg-1 [middle dot] min-1) or alfentanil (loading dose, 50 [mu]g/kg; maintenance infusion, 1 [mu]g [middle dot] kg-1 [middle dot] min-1) as the analgesic component of TIVA. They were combined with propofol (loading dose, 2 mg/kg; maintenance infusion, 100 [mu]g [middle dot] kg-1 [middle dot] min-1). To insure an equal state of anesthesia, the opioids were titrated to maintain heart rate and mean arterial pressure within 20% of baseline, and propofol was titrated to keep the bispectral index (BIS) less than 60. Neuromuscular blockade was achieved with succinylcholine. Drug dosages and the times from cessation of anesthesia to extubation, verbal response, recovery of ventilation, and neuropsychological testing, orientation, and discharge readiness were recorded.
Results: Demographics, duration of surgery, and anesthesia were similar between the two groups. Both groups received similar propofol doses. There were no difference in BIS values preoperatively (mean, 96), intraoperatively (mean, 55), and postoperatively (mean, 96). Recovery of BIS and times for verbal response did not differ. At 20, 30, and 40 min after terminating the opioid infusion, the peripheral oxygen saturation and respiratory rate were significantly higher in the remifentanil group compared with the alfentanil group. 相似文献
Methods: Basal anesthesia and constant blood gas tensions were maintained with [alpha]-chloralose and mechanical ventilation. PNA, HR, MAP, and maximum changes in HR and MAP ([DELTA]HR, [DELTA]MAP) evoked by electrical nerve stimulation of tibial nerves were recorded. The comparative effects were observed for propofol at infusion rates from 0.05 to 3.2 mg [middle dot] kg-1 [middle dot] min-1 (group I) and remifentanil from 0.0125 to 12.8 [mu]g [middle dot] kg-1 [middle dot] min-1 alone (group II), and during constant infusions of propofol at rates of 0.1 and 0.8 mg [middle dot] kg-1 [middle dot] min-1 (groups III and IV, respectively). Finally, the effect of remifentanil on propofol blood levels was observed (group V).
Results: The infusion rates for 50% depression (ED50) of PNA, [DELTA]HR, and [DELTA]MAP were 0.41, 1.32, and 1.58 mg [middle dot] kg-1 [middle dot] min-1 for propofol, and 0.115, 0.125, and 1.090 [mu]g [middle dot] kg-1 [middle dot] min-1 for remifentanil, respectively. The ratios for the ED50 values of [DELTA]HR and [DELTA]MAP to PNA were 3.2 and 3.9 for propofol, and 1.1 and 9.5 for remifentanil, respectively. Analysis of the expected and observed responses and isobologrms showed that although their combined effects on PNA, resting HR, and MAP, and [DELTA]MAP were synergistic for [DELTA]HR, they were merely additive. Remifentanil had no effect on propofol blood levels. 相似文献
Methods: Ten healthy male volunteers with a laryngeal mask for artificial ventilation received remifentanil at an infusion rate of 2 and 4 [mu]g [middle dot] kg-1 [middle dot] min-1 under normocapnia, hypocapnia, and hypercapnia. Stable xenon-enhanced computed tomography and transcranial Doppler ultrasonography of the left middle cerebral artery were used to assess rCBF and mean CBFv, respectively. If required, blood pressure was maintained within baseline values with intravenous phenylephrine to avoid confounding effects of altered hemodynamics.
Results: Hemodynamic parameters were maintained constant over time. Remifentanil infusion at 2 and 4 [mu]g [middle dot] kg-1 [middle dot] min-1 significantly decreased rCBF and mean CBFv. Both rCBF and mean CBFv increased as the arterial carbon dioxide tension increased from hypocapnia to hypercapnia, indicating that cerebrovascular reactivity remained intact. The average slopes of rCBF reactivity were 0.56 +/- 0.27 and 0.49 +/- 0.28 ml [middle dot] 100 g-1 [middle dot] min-1 [middle dot] mmHg-1 for 2 and 4 [mu]g[middle dot]kg-1[middle dot]min-1 remifentanil, respectively (relative change in percent/mmHg: 1.9 +/- 0.8 and 1.6 +/- 0.5, respectively). The average slopes for mean CBFv reactivity were 1.61 +/- 0.95 and 1.54 +/- 0.83 cm [middle dot] s-1 [middle dot] mmHg-1 for 2 and 4 [mu]g [middle dot] kg-1 [middle dot] min-1 remifentanil, respectively (relative change in percent/mmHg: 1.86 +/- 0.59 and 1.79 +/- 0.59, respectively). Preanesthesia and postanesthesia values of rCBF and mean CBFv did not differ. 相似文献
Methods: Sixteen patients were randomly assigned to undergo a 6-h stable isotope infusion study (3 h fasted, 3 h feeding) on the second day after colorectal surgery performed with or without perioperative epidural blockade. Protein synthesis, breakdown and oxidation, glucose production, and clearance were measured by l-[1-13C]leucine and [6,6-2H2]glucose.
Results: Epidural blockade did not affect protein and glucose metabolism in the fasted state. Parenteral alimentation decreased endogenous protein breakdown and glucose production to the same extent in both groups. Administration of glucose and amino acids was associated with an increase in whole body protein synthesis that was modified by the type of analgesia, i.e., protein synthesis increased by 13% in the epidural group (from 93.3 +/- 16.6 to 104.5 +/- 11.1 [mu]mol [middle dot] kg-1 [middle dot] h-1) and by 4% in the patient-controlled analgesia group (from 90.0 +/- 27.1 to 92.9 +/- 14.8 [mu]mol [middle dot] kg-1 [middle dot] h-1;P = 0.054). 相似文献
Methods: After institutional approval and informed patient consent were obtained, 23 patients scheduled to undergo supratentorial tumor surgery were randomly assigned to remifentanil or fentanyl infusion groups in a double-blinded manner. Midazolam, thiopental, and pancuronium induction was followed by equipotent narcotic loading infusions of remifentanil (1 [micro sign]g [middle dot] kg-1 [middle dot] min-1) or fentanyl (2 [micro sign]g [middle dot] kg-1 [middle dot] min-1) for 5-10 min. Patients were ventilated with 2:1 nitrous oxide-oxygen, and opioid rates were reduced and then titrated to a stable hemodynamic effect. After dural exposure, CBF was measured by the intravenous133 xenon technique at normocapnia and hypocapnia. Reactivity of CBF to carbon dioxide was calculated as the absolute increase in CBF per millimeters of mercury increase in the partial pressure of carbon dioxide (PaCO2). Data were analyzed by repeated-measures analysis of variance, unpaired Student's t tests, or contingency analysis.
Results: In the remifentanil group (n = 10), CBF decreased from 36 +/- 11 to 27 +/- 8 ml [middle dot] 100 g-1 [middle dot] min-1 as PaCO2 decreased from 33 +/- 5 to 25 +/- 2 mmHg. In the fentanyl group (n = 8), CBF decreased from 37 +/- 11 to 25 +/- 6 ml [middle dot] 100 g-1 [middle dot] min-1 as PaCO2 decreased from 34 +/- 3 to 25 +/- 3 mmHg. Absolute carbon dioxide reactivity was preserved with both agents: 1 +/- 1.2 ml [middle dot] 100 g-1 [middle dot] min-1 [middle dot] mmHg-1 for remifentanil and 1.5 +/- 0.5 ml [middle dot] 100 g-1 [middle dot] min-1 [middle dot] mmHg-1 for fentanyl (P = 0.318). 相似文献
Methods: Sixty adult patients undergoing open colorectal surgery were randomly assigned to receive either remifentanil or 70% nitrous oxide along with isoflurane anesthesia. After morphine analgesia titration in the postanesthesia care unit, patient-controlled analgesia was commenced. Morphine consumption and pain were scored at rest and during cough or movement for 24 h.
Results: The mean remifentanil infusion rate was 0.17 [mu]g [middle dot] kg-1 [middle dot] min-1. The median visual analog pain score on arrival in the postanesthesia care unit was 1 (0-10) in the nitrous oxide group and 3 (0-9) in the remifentanil group (P < 0.05). Otherwise, there was no difference in pain scores at 5, 10, and 15 min and no difference in the total morphine consumption during the stay in the postanesthesia care unit. The two groups had similar total morphine consumption in the first 24 h and pain scores at rest and during movement. The incidence of postoperative nausea and vomiting was 10% in both groups. There was no difference in the sedation scores. 相似文献
Methods: With institutional review board approval and written informed consent, 120 adult patients scheduled to undergo minor orthopedic surgery were randomized to receive a propofol-remifentanil anesthetic controlled by Narcotrend, by BIS(R), or solely by clinical parameters. Anesthesia was induced with 0.4 [mu]g [middle dot] kg-1 [middle dot] min-1 remifentanil and a propofol target-controlled infusion at 3.5 [mu]g/ml. After intubation, remifentanil was reduced to 0.2 [mu]g [middle dot] kg-1 [middle dot] min-1, whereas the propofol infusion was adjusted according to clinical parameters or to the following target values: during maintenance to D0 (Narcotrend) or 50 (BIS(R)); 15 min before the end of surgery to C1 (Narcotrend) or 60 (BIS(R)). Recovery times were recorded by a blinded investigator, and average normalized propofol consumption was calculated from induction and maintenance doses.
Results: The groups were comparable for demographic data, duration of anesthesia, and mean remifentanil dosages. Compared with standard practice, patients with Narcotrend or BIS(R) monitoring needed significantly less propofol (standard practice, 6.8 +/- 1.2 mg [middle dot] kg-1 [middle dot] h-1vs. Narcotrend, 4.5 +/- 1.1 mg [middle dot] kg-1 [middle dot] h-1 or BIS(R), 4.8 +/- 1.0 mg [middle dot] kg-1 [middle dot] h-1;P < 0.001), opened their eyes earlier (9.3 +/- 5.2 vs. 3.4 +/- 2.2 or 3.5 +/- 2.9 min), and were extubated sooner (9.7 +/- 5.3 vs. 3.7 +/- 2.2 or 4.1 +/- 2.9 min). 相似文献
Methods: Positron emission tomography measurements were performed with injection of 7 mCi 15O-water during nonpainful heat and painful heat stimulation of the volar forearm. Three experimental conditions were used during both sensory stimuli: saline, 0.05 [mu]g [middle dot] kg-1 [middle dot] min-1 remifentanil, and 0.15 [mu]g [middle dot] kg-1 [middle dot] min-1 remifentanil. Cardiovascular and respiratory parameters were monitored noninvasively. Across the three conditions, dose-dependent effects of remifentanil on regional cerebral blood flow were analyzed on a pixel-wise basis using a statistical parametric mapping approach.
Results: During saline infusion, regional cerebral blood flow increased in response to noxious thermal stimulation in a number of brain regions as previously reported. There was a reduction in pain-related activations with increasing doses of remifentanil in the thalamus, insula, and anterior and posterior cingulate cortex. Increasing activation occurred in the cingulofrontal cortex (including the perigenual anterior cingulate cortex) and the periaqueductal gray. 相似文献
Methods: Isocapnic, acute hypoxic ventilatory responses (AHRs) were measured in 11 volunteers. AHR and normoxic ventilation were measured under the following conditions: (1) eyes closed, no audio stimulation (low wakefulness); (2) low wakefulness conditions plus painful thermal stimulation; and (3) playing a computer game (high wakefulness), each with and without remifentanil infusion.
Results: The average (+/- sd) remifentanil dose was 0.035 +/- 0.012 [mu]g [middle dot] kg-1 [middle dot] min-1. Both normoxic and hypoxic ventilation were significantly reduced by the remifentanil infusion under all three conditions. The AHR values under low wakefulness conditions were 0.33 +/- 0.19 and 0.89 +/- 0.49 l [middle dot] min-1 [middle dot] sat-1 with and without remifentanil, respectively (P < 0.05). High wakefulness significantly increased AHR with and without remifentanil, whereas low wakefulness with pain did not. However, high wakefulness with remifentanil did not increase the AHR back to what was observed during low wakefulness without remifentanil. 相似文献
Methods: Twenty-eight mature, female, anesthetized sheep (weight, 30.5 +/- 3.6 kg) underwent cecal ligation and perforation and were randomized into four groups of seven animals to be treated with norepinephrine, dopamine-norepinephrine, dobutamine-norepinephrine, or no adrenergic agent. In all groups, lactated Ringer's solution was administered to restore cardiac filling pressures to baseline. In the norepinephrine group, norepinephrine (0.5-5 [mu]g [middle dot] kg-1 [middle dot] min-1) was titrated to maintain mean arterial pressure between 75-85 mmHg. In the dopamine-norepinephrine group, dopamine was given first, and norepinephrine was added only when mean arterial pressure remained below 75 mmHg despite the infusion of 20 [mu]g [middle dot] kg-1 [middle dot] min-1 dopamine. In the dobutamine-norepinephrine group, dobutamine was started at the same time as norepinephrine and titrated up to 20 [mu]g [middle dot] kg-1 [middle dot] min-1 to get a 15% increase in cardiac output.
Results: The dobutamine-norepinephrine group had greater cardiac output; superior mesenteric blood flow, oxygen delivery (Do2), and oxygen consumption ([latin capital V with dot above]o2); and lower blood lactate concentration and partial pressure of carbon dioxide (Pco2) gap than the controls did. Cumulative urine output was significantly higher in the dobutamine-norepinephrine group than in the other groups. Survival time was significantly longer in the dobutamine-norepinephrine (24 +/- 4 h), dopamine- norepinephrine (24 +/- 6 h), and norepinephrine (20 +/- 1 h) groups than the control group (17 +/- 2 h;P < 0.05 vs. other groups), and significantly longer in the combined dopamine-norepinephrine and dobutamine-norepinephrine groups (24 +/- 5 h) than in the norepinephrine alone group (P < 0.05). Histologic examination of lung biopsies revealed less severe lesions in the dobutamine-norepinephrine group than in the control and norepinephrine alone groups. Anatomic alterations in the lung, liver, and small intestine were less severe in the dobutamine-norepinephrine group than in the other groups. 相似文献
Methods: In the early postoperative period after implantation of a total artificial heart, nine ventilated patients requiring short general anesthesia were included in this study. After anesthesia was induced with 0.3 mg/kg intravenous etomidate, the artificial heart settings were modified to render cardiac output "preload-independent." While maintenance of anesthesia was ensured by a continuous infusion of etomidate, increased concentrations of remifentanil (from 0.1 to 1 [mu]g [middle dot] kg-1 [middle dot] min-1) were infused in steps of 5 min under hemodynamic monitoring, including left and right atrial pressures, systemic and pulmonary arterial pressures, and left and right cardiac indices. The invasive procedure was started under the highest concentration of remifentanil tolerated by the patient. Infusion of remifentanil was stopped at the end of the invasive procedure, while etomidate infusion was maintained. New hemodynamic measurements were performed at the end of the 12-min recovery period.
Results: Remifentanil produced a dose-dependent and significant decrease in systemic arterial pressure and vascular resistances (n = 9) from a concentration of 0.25 [mu]g [middle dot] kg-1 [middle dot] min-1. No significant changes were observed on pulmonary vascular resistances (n = 6). Neither right (n = 9) nor left (n = 6) atrial pressures were affected by remifentanil infusion. Hemodynamic variables returned to baseline value over the 12-min recovery period. 相似文献
Methods: Ten right-handed male volunteers were included in a 15O-water PET study. Seven underwent three conditions: control (saline), low remifentanil (0.05 [mu]g [middle dot] kg-1 [middle dot] min-1), and moderate remifentanil (0.15 [mu]g [middle dot] kg-1 [middle dot] min-1). The remaining three participated in the low and moderate conditions. A semi-randomized study protocol was used with control and remifentanil conditions 3 or more months apart. The order of low and moderate conditions was randomized. Cardiovascular and respiratory parameters were monitored. Categoric comparisons between the control, low, and moderate conditions and a pixelwise correlation analysis across the three conditions were performed (P < 0.05, corrected for multiple comparisons) using statistical parametric mapping.
Results: Cardiorespiratory parameters were maintained constant over time. At the low remifentanil dose, significant increases in relative rCBF were noted in the lateral prefrontal cortices, inferior parietal cortices, and supplementary motor area. Relative rCBF decreases were observed in the basal mediofrontal cortex, cerebellum, superior temporal lobe, and midbrain gray matter. Moderate doses further increased rCBF in mediofrontal and anterior cingulate cortices, occipital lobe transition, and caudal periventricular grey. Significant decreases were detected in the inferior parietal lobes. These dose-dependent effects of remifentanil on rCBF were confirmed by a correlation analysis. 相似文献
Methods: Potency was determined using a single-dose (20, 26, 33, or 40 [mu]g/kg) technique. Neuromuscular block was assessed by monitoring the electromyographic response of the adductor pollicis to supramaximal train-of-four stimulation of the ulnar nerve at 2 Hz.
Results: Least-squares linear regression analysis of the log-probit transformation of dose and maximal response yielded median effective dose (ED50) and 95% effective dose (ED95) values for infants (29 +/- 3 [mu]g/kg and 43 +/- 9 [mu]g/kg, respectively) that were similar to those for children (29 +/- 2 [mu]g/kg and 47 +/- 7 [mu]g/kg, respectively). The mean infusion rate necessary to maintain 90-99% neuromuscular block during the first hour in infants (1.9 +/- 0.4 [mu]g [middle dot] kg-1 [middle dot] min-1; range: 1.3-2.5 [mu]g [middle dot] kg-1 [middle dot] min-1) was similar to that in children (2.0 +/- 0.5 [mu]g [middle dot] kg-1 [middle dot] min-1; range: 1.3-2.9 [mu]g [middle dot] kg-1 [middle dot] min-1). 相似文献
Methods: Part I study: 54 patients undergoing total abdominal hysterectomy were randomly divided into two groups (n = 27 per group). The patients in the control group received 0.9% sodium chloride solution, whereas the patients in the magnesium group received magnesium (50 mg/kg as a bolus, then 8 mg [middle dot] kg-1 [middle dot] h-1). To maintain mean arterial blood pressure (MAP) and heart rate (HR) at baseline value, the propofol infusion rate was changed when the MAP or the HR changed. The amount of propofol infused excluding the bolus dosage was divided by patient's body weight and total infusion time. Part II study: Another 20 patients were randomly divided into two groups (n = 10 per group). When the MAP and HR had been maintained at baseline value and the propofol infusion rate had been maintained at 80 [mu]g [middle dot] kg-1 [middle dot] min-1 (magnesium group) and 160 [mu]g [middle dot] kg-1 [middle dot] min-1 (control group), bispectral index (BIS) values were measured.
Results: Part I: The mean propofol infusion rate in the magnesium group (81.81 +/- 13.09 [mu]g [middle dot] kg-1 [middle dot] min-1) was significantly less than in the control group (167.57 +/- 47.27). Part II: BIS values in the control group (40.70 +/- 3.89) were significantly less than those in the magnesium group (57.80 +/- 7.32). 相似文献