A comparison of remifentanil and fentanyl in patients undergoing carotid endarterectomy

BACKGROUND AND AIM: We investigated the haemodynamic stability and emergence characteristics of isoflurane/nitrous oxide anaesthesia supplemented with remifentanil or fentanyl in patients undergoing carotid endarterectomy. METHODS: Anaesthesia was induced with propofol (1-2 mg kg-1) and either remifentanil (0.5 microgram kg-1) or fentanyl (1 microgram kg-1), followed by an infusion of remifentanil (0.2 microgram kg-1 min-1) or fentanyl (2 micrograms kg-1 h-1). RESULTS: There were no significant differences between the groups in haemodynamic variables, postoperative pain, nausea or vomiting. After induction there was a significant decrease in mean arterial pressure for both groups (P < 0.001) and a decrease in heart rate (P = 0.001) in the remifentanil group. In both groups these haemodynamic changes continued during maintenance of anaesthesia (P < 0.05). The time to eye opening after surgery was significantly shorter with remifentanil compared with fentanyl (6.62 +/- 3.89 vs. 18.0 +/- 15.18 min, P = 0.015). CONCLUSION: Remifentanil appears to be a comparable opioid to fentanyl when supplementing isoflurane/nitrous oxide anaesthesia for carotid endarterectomy.     

A comparison of remifentanil and fentanyl for fast track paediatric cardiac anaesthesia

BACKGROUND: Fast track anaesthetic protocols for cardiac surgical patients have been developed to facilitate early tracheal extubation. We compared anaesthetics based on either remifentanil or fentanyl for fast track paediatric cardiac anaesthesia. METHODS: Fifty patients with atrial septal defect or simple ventricular septal defect who were deemed suitable for fast track anaesthetic management were randomly assigned to group R (remifentanil) or group F (fentanyl). After sevoflurane induction, patients received either R infusion or F bolus. Following intubation, isoflurane 0.5 MAC was administered to all patients. Blood pressure (BP) and heart rate (HR) were recorded at baseline and pre- and postinduction, intubation, skin incision and sternotomy. Other parameters measured included time to extubation, reintubation rate and requirements for postoperative analgesia, ondansetron, and nitroprusside in the paediatric intensive care unit. RESULTS: BP decreased similarly from baseline in both groups. Decreases in HR over time were significantly greater in group R. Haemodynamic response to incision/sternotomy was low and similar in both groups. There were no significant differences in extubation time, reintubation incidence, postoperative narcotic requirements, postoperative hypertension or postoperative nausea/vomiting. CONCLUSIONS: The remifentanil based anaesthetic was associated with a significantly slower HR than the fentanyl based anaesthetic. The clinical implications of the slower HR during remifentanil anaesthesia could be important and should be investigated.     

A comparison of remifentanil and fentanyl in patients undergoing surgery for intracranial mass lesions

We compared the effects of remifentanil versus fentanyl during surgery for intracranial space-occupying lesions. Patients were randomly assigned to receive either remifentanil (0.5 microg. kg(-1). min(-1) IV during the induction of anesthesia reduced to 0.25 microg. kg(-1). min(-1) after endotracheal intubation; n = 49) or fentanyl (dose per usual practice of the anesthesiologist; n = 54). Anesthesia maintenance doses of isoflurane, nitrous oxide, and opioid were at the anesthesiologist's discretion for both groups. There were no differences between opioid groups for the frequency of responses (hemodynamic, movement, and tearing) to intubation, pinhead holder placement, skin incision, or closure of the surgical wound. Adverse event frequencies were similar between groups. Times to follow verbal commands (P < 0.001) and tracheal extubation (P = 0. 04) were more rapid for remifentanil. The percentage of patients with a normal recovery score (were alert or arousable to quiet voice, were oriented, were able to follow commands, had motor function unchanged from their preoperative evaluation, were not agitated, and had modified Aldrete Scores of 9-10) at 10 min after surgery was more for remifentanil (45% vs 18%; P = 0.005). By 20 min, no difference between groups existed (P = 0.27). Anesthesiologists used more isoflurane in the fentanyl group (4.22 vs 1.93 minimum alveolar anesthetic concentration hours). Neurosurgeons, blinded to treatment group, favored the use of remifentanil. Similar frequencies of light anesthesia responses and other adverse events suggest that intraoperative depths of anesthesia were similar in the two groups. Under these conditions, emergence was more rapid with remifentanil. This is consistent with the necessity for less isoflurane use in the remifentanil group and the intrinsic rapid clearance of this opioid. IMPLICATIONS: Patients given remifentanil-based anesthesia for craniotomy had faster recovery times from anesthesia than did those given fentanyl-based anesthesia.     

A comparison of fentanyl, sufentanil, and remifentanil for fast-track cardiac anesthesia

Cardiac surgery is estimated to cost $27 billion annually in the United States. In an attempt to decrease the costs of cardiac surgery, fast-track programs have become popular. The purpose of this study was to compare the effects of three different opioid techniques for cardiac surgery on postoperative pain, time to extubation, time to intensive care unit discharge, time to hospital discharge, and cost. Ninety adult patients undergoing cardiac surgery were randomized to a fentanyl-based, sufentanil-based, or remifentanil-based anesthetic. Postoperative pain was measured at 30 min after extubation and at 6:30 AM on the first postoperative day. Pain scores at both times were similar in all three groups (P > 0.05). Median ventilator times of 167, 285, and 234 min (P > 0.05), intensive care unit stays of 18.8, 19.8, and 21.5 h (P > 0.05), and hospital stays of 5, 5, and 5 days (P > 0.05) for the Fentanyl, Sufentanil, and Remifentanil groups did not differ. Three patients needed to be tracheally reintubated: two in the Sufentanil group and one in the Fentanyl group. Median anesthetic costs were largest in the Remifentanil group ($140.54 [$113.54-$179.29]) and smallest in the Fentanyl group ($43.33 [$39.36-$56.48]) (P < or = 0.01), but hospital costs were similar in the three groups: $7841 (Fentanyl), $5943 (Sufentanil), and $6286 (Remifentanil) (P > 0.05). We conclude that the more expensive but shorter-acting opioids, sufentanil and remifentanil, produced equally rapid extubation, similar stays, and similar costs to fentanyl, indicating that any of these opioids can be recommended for fast-track cardiac surgery. IMPLICATIONS: To conserve resources for cardiac surgery, fentanyl-, sufentanil-, and remifentanil-based anesthetics were compared for duration of mechanical ventilation, intensive care unit length of stay, hospital length of stay, and cost. The shorter-acting anesthetics, sufentanil and remifentanil, produced equally rapid extubation, similar stays, and similar costs to fentanyl; thus, any of these opioids can be recommended for fast-track cardiac surgery.     

Hemodynamics and emergence profile of remifentanil versus fentanyl prospectively compared in a large population of surgical patients

STUDY OBJECTIVE: To compare the responses to, and hemodynamics associated with surgical stress, recovery profiles, and anesthesiologists' satisfaction following balanced general anesthesia using either remifentanil or fentanyl in a large-scale population. DESIGN: Prospective, 1:1 single blind, randomized, controlled effectiveness study in which patients received either remifentanil or fentanyl in combination with a hypnotic-based anesthesia regimen of either isoflurane or propofol. SETTING: Multicenter study including 156 hospitals and ambulatory surgery facilities. PATIENTS: 2,438 patients (1,496 outpatients and 942 inpatients), 18 years of age or older, scheduled for elective surgeries under general endotracheal anesthesia, with an expected duration of unconsciousness > or =30 minutes. INTERVENTIONS: Patients were randomized to receive either intravenous (IV) remifentanil (0.5 microg/kg/min for induction and intubation, with the infusion rate decreased to 0.25 microg/kg/min after intubation) or IV fentanyl (administered according to anesthesiologists' usual practice) as the opioid during surgery. Concomitant hypnotic drugs were either propofol and/or isoflurane (with or without nitrous oxide) titrated according to protocol. Transition analgesia with either morphine or fentanyl was given to the remifentanil patients and, at the anesthesiologists' discretion, in the fentanyl patients. MEASUREMENTS: Vital signs, adverse events, and emergence profiles were assessed and recorded. Recovery profile was assessed by recording time spent in the postanesthesia care unit and step-down recovery unit, number and timing of adverse events, timing and dosage of rescue medications, and time to eligibility for discharge (to home or to hospital room). Anesthesiologists' satisfaction with the anesthetic regimen was assessed at the end of surgery. MAIN RESULTS: Remifentanil-treated patients exhibited lower systolic and diastolic blood pressures (by 10-15 mmHg) and lower heart rates (by 10-15 bpm) intraoperatively compared to the fentanyl-treated patients. This difference promptly disappeared on emergence. Remifentanil-treated patients responded to verbal command, left the operating room, and (for outpatients) were discharged home sooner than fentanyl-treated patients. Anesthesiologists rated the predictability of response to intraoperative titration, assessment of hemodynamic profiles, and the quality of anesthesia higher in the remifentanil-treated patients. CONCLUSIONS: This study confirms previous observations on the hemodynamic properties associated with remifentanil and extends these to a wider context than previously reported. These characteristics provide clinicians with an alternative in opioid-based anesthesia.     

A randomized double-blinded multicenter comparison of remifentanil versus fentanyl when combined with isoflurane/propofol for early extubation in coronary artery bypass graft surgery

We compared a fentanyl/isoflurane/propofol regimen with a remifentanil/isoflurane/propofol regimen for fast-track cardiac anesthesia in a prospective, randomized, double-blinded study on patients undergoing elective coronary artery bypass graft surgery. Anesthesia was induced with a 1-min infusion of 0.5 mg/kg propofol followed by 10-mg boluses of propofol every 30 s until loss of consciousness. After 0.2 mg/kg cisatracurium, a blinded continuous infusion of remifentanil at 1 microg. kg(-1). min(-1) or the equivalent volume rate of normal saline was then started. In addition, a blinded bolus syringe of 1 microg/kg remifentanil or 10 microg/kg fentanyl, respectively, was given over 3 min. Blinded remifentanil, 1 microg. kg(-1). min(-1) (or the equivalent volume rate of normal saline), together with 0.5% isoflurane, were used to maintain anesthesia. Significantly more patients (P < 0.01) in the fentanyl regimen experienced hypertension during skin incision and maximum sternal spread compared with patients in the remifentanil regimen. There were no differences between the groups in time until extubation, discharge from the surgical intensive care unit, ST segment and other electrocardiogram changes, catecholamine levels, or cardiac enzymes. The remifentanil-based anesthetic (consisting of a bolus followed by a continuous infusion) resulted in significantly less response to surgical stimulation and less need for anesthetic interventions compared with the fentanyl regimen (consisting of an initial bolus, and followed by subsequent boluses only to treat hemodynamic responses) with both drug regimens allowing early extubation. IMPLICATIONS: Both fentanyl and the newer opioid remifentanil, when each is combined with isoflurane and propofol, allowed for fast-track cardiac anesthesia. The remifentanil regimen used in this study resulted in significantly less hemodynamic response to surgical stimulation.     

Propofol anesthesia for craniotomy: a double-blind comparison of remifentanil, alfentanil, and fentanyl

For patients undergoing craniotomy, it is desirable to have stable and easily controllable hemodynamics during intense surgical stimulation. However, rapid postoperative recovery is essential to assess neurologic function. Remifentanil, an ultra-short-acting mu-opioid receptor agonist, may be the ideal agent to confer the above characteristics. In this prospective randomized study, we compared the hemodynamic stability, recovery characteristics, and the dose of propofol required for maintaining anesthesia supplemented with an infusion of remifentanil, alfentanil, or fentanyl in 34 patients scheduled for supratentorial craniotomy. With routine monitors in place, anesthesia was induced with propofol (2-3 mg/kg), atracurium (0.5 mg/kg), and either remifentanil (1 microg/kg), alfentanil (10 microg/kg), or fentanyl (2 micro/kg). The lungs were ventilated with O2/air to mild hypocapnia. Anesthesia was maintained with infusions of propofol (50-100 microg/kg/min) and either remifentanil (0.2 microg/kg/min), alfentanil (20 microg/kg/h), or fentanyl (2 microg/kg/h). There were no significant differences among the groups in the dose of propofol maintenance required, heart rate, or mean arterial pressure. However, the time to eye opening (minutes) was significantly shorter in the remifentanil compared to the alfentanil group (6+/-3; 21+/-14; P = 0.0027) but not the fentanyl group (15+/-9). We conclude that remifentanil is an appropriate opioid to use in combination with propofol during anesthesia for supratentorial craniotomy.     

瑞芬太尼、芬太尼对过度肥胖患者麻醉效果及麻醉复苏质量的影响

目的 探讨芬太尼和瑞芬太尼对于肥胖患者全身麻醉效果及复苏的影响,探索联合应用两种药物的可行性,并找到较为可行的联合方式.方法 按随机区组设计将实施全身麻醉的肥胖患者分为4组,每组20例,分别是芬太尼组(F组),瑞芬太尼组(R组),芬太尼复合瑞芬太尼l组(RF1组)和芬太尼复合瑞芬太尼2组(RF2组),比较4组患者的全身...     

等效镇痛剂量瑞芬太尼、舒芬太尼和芬太尼的镇静效应和不良反应的比较

目的 比较等效镇痛剂量瑞芬太尼、舒芬太尼和芬太尼的镇静效应和不良反应.方法 拟行腹腔镜手术的女性患者80例,年龄18～39岁,BMI 18～25 kg/m2,身高155～175 cm,ASA分级Ⅰ级.采用随机数字表法,将患者随机分为4组(n=20):对照组(C组)、瑞芬太尼组(R组)、舒芬太尼组(S组)和芬太尼组(F组).R组、S组和F组分别经2 min静脉注射瑞芬太尼2 μg/kg、舒芬太尼0.2 μg/kg、芬太尼2 μg/kg,C组给予等容量生理盐水10 ml.分别于给药前(基础状态)、给药后2、4、6、8、10 min时记录警觉/镇静评分(OAA/S评分)、小波指数(WLI)和呼吸频率(RR).计算给药后各时间点OAA/S评分、WLI、RR与基础值的差值,分别用dOAA/S评分、dWLI、dRR表示,采用梯形法计算给药后10 min内dOAA/S评分、dWLI和dRR的曲线下面积(AUC).记录给药后10 min内呼吸暂停、肌肉强直、恶心呕吐、瘙痒、头晕、心动过缓、大汗和皮疹等的发生情况.结果 与C组比较,R组、S组和F组给药后OAA/S评分、WLI和RR的最低值降低,dOAA/SAPC、dWLIAPC,和dRRAPC均升高(P＜0.05);R组、S组和F组dOAA/SAPC的比值为1.05∶1.99∶1,dWLIAPC的比值为1.34∶3.31∶1,dRRAPC的比值为1.95∶1.37∶1.与C组比较,R组呼吸暂停、恶心呕吐、瘙痒和头晕的发生率升高,S组瘙痒和头晕的发生率升高,F组头晕发生率升高(P＜0.05).结论 上述3种药物等效镇痛剂量用于清醒镇静时,舒芬太尼的镇静作用最强,瑞芬太尼的呼吸抑制作用最明显.     

The effect of acutely induced hepatic failure on remifentanil and fentanyl blood levels in a pig model

BACKGROUND AND OBJECTIVE: Opioids and especially fentanyl are widely used during the intensive care unit management of intracranial pressure in fulminant hepatic failure patients as well as during and after liver transplantation. The newer synthetic opioid remifentanil is also increasingly being used in critical care patients. Due to a lack of data relating to the influence of acute hepatic failure on remifentanil and fentanyl pharmacokinetics, this study was designed in order to determine the impact of this condition on the blood levels of these opioids using a pig model. METHODS: Twenty pigs were randomly assigned to one of two groups: A group with surgically induced acute hepatic failure by hepatic devascularization (acute hepatic failure, n=10) and a control group (SHAM, n=10), subjected to a SHAM operation. Postoperatively, five animals in each group were administered remifentanil (1 microg kg-1 min-1) or fentanyl (0.2 microg kg-1 min-1) by continuous intravenous infusion. Blood samples for determination of drug concentrations were withdrawn at 0 h and 0.5, 1, 5, 7, 9 h after initiation of dosing. RESULTS: Significantly higher blood concentrations were found in animals with acute hepatic failure compared to SHAM-operated animals receiving remifentanil at 5 h (P=0.003), 7 h (P=0.007) and 9 h (P=0.004) and fentanyl at 7 h (P<0.0005) and 9 h (P=0.05). The small number and the great variability in drug concentrations did not allow a detailed kinetic analysis to be performed. Approximate clearance values were found to be greater for the SHAM compared with the acute hepatic failure animals for both fentanyl and remifentanil. CONCLUSIONS: Hepatic devascularization in our porcine acute hepatic failure model, appears to have significantly altered the disposition of fentanyl and unexpectedly remifentanil. These changes were thought to be brought about by severe disruption of blood flow and biotransformation in the liver, as well as by haemodynamic changes in the acute hepatic failure animals.     

Patient satisfaction with awake craniotomy for tumor surgery: a comparison of remifentanil and fentanyl in conjunction with propofol

In this study we compared the effectiveness of the use of remifentanil to fentanyl in conjunction with propofol in providing conscious sedation for awake craniotomy for tumor surgery and to assess patient satisfaction with both techniques. The ability to maintain appropriate levels of sedation, adequate analgesia, and hemodynamic stability was assessed in 50 patients randomized to receive either fentanyl or remifentanil. All complications were documented. Patients were interviewed at 1 h, 4 h, and 24 h after surgery to note their recall of procedure and pain and their overall satisfaction. There were no differences in sedation and pain scores or in hemodynamic and respiratory variables between the two groups. The incidence of intraoperative complications was not different (fentanyl, 14; remifentanil, 16). Respiratory complications occurred in 9 (18%) patients (fentanyl 6, remifentanil 3). The recall and satisfaction scores were not different; 93% of all patients were completely satisfied at all interview times. The use of remifentanil infusion in conjunction with propofol is a good alternative to fentanyl and propofol for conscious sedation for the awake craniotomy and these techniques are both well accepted by the patient.     

A comparison of the cost-effectiveness of remifentanil versus fentanyl as an adjuvant to general anesthesia for outpatient gynecologic surgery

The unique pharmacokinetic properties of remifentanil make it a potentially useful adjuvant during general anesthesia for ambulatory surgery. Fentanyl, inexpensive and easy to administer, is the most common opioid used for this purpose. As an adjuvant to general anesthesia for outpatient gynecologic surgery, we questioned if remifentanil was cost-effective as an alternative to fentanyl. Thirty-four patients undergoing gynecologic laparoscopy or hysteroscopy were prospectively and randomly assigned to a standard practice (n = 18) or a study (n = 16) group. Standard practice patients received fentanyl (3 microg/kg) before induction; study patients received remifentanil by continuous infusion (0.5 microg x kg. min(-1) at induction, then 0.2 microg x kg x min(-1)). Sevoflurane was titrated to a Bispectral index value of 40-55. We investigated recovery profiles, patient and health care professional satisfaction, and drug costs. The incidence of rescue antiemetic treatment (2 of 16 vs. 8 of 18; P = 0.013) and the nausea visual analog scale scores during second stage recovery (0.2 vs. 0.6; P = 0.044) were more frequent in the study group. However, the incidence of intraoperative adverse events and other postoperative sequelae, recovery times, pain and nausea visual analog scale scores, opioid analgesic dosage requirements in the postanesthetic care unit, and satisfaction survey responses were similar between groups. Perioperative drug costs per patient were $17.72 more in the remifentanil (vs. fentanyl) group.     

A comparison of effects of alfentanil, fentanyl, and remifentanil on hemodynamic and respiratory parameters during stereotactic brain biopsy

The aim of this study was to compare the effects of 3 different sedative-analgesic regimens in patients with intracranial mass lesions undergoing stereotactic brain biopsy. A 135 outpatients with American Society of Anesthesiologists I to II were divided into 3 groups: group A (n = 45) received a loading dose of IV alfentanil 7.5 microg/kg followed by infusion rate of 0.25 microg/kg/min; group F (n = 45) received a bolus dose of 1 microg/kg IV fentanyl and repeated as needed; and group R (n = 45) received infusion of 0.05 microg/kg/min remifentanil. Target level of sedation was 3 to 4 of the Ramsay Sedation Scale. Systolic and diastolic blood pressure, heart rate, respiratory rate, peripheric oxygen saturation (SpO2), and end-tidal carbon dioxide were recorded at different stages of the procedures. The patients in group F had significantly lower mean heart rate than those in groups A and R, but this was not in the limits of the bradycardia. The patients in group A had significantly lower mean SpO2 than those in the other groups, but mean SpO2 values did not drop below 94%. There were no significant differences in end-tidal carbon dioxide and respiratory rate values among the groups. Our results suggest that all 3 regimens have relatively similar hemodynamic and respiratory responses. The use of bolus fentanyl technique caused less hemodynamic stability. The continuous infusion technique of remifentanil or alfentanil provided better control on hemodynamic parameters.     

Comparison of remifentanil and fentanyl in anaesthesia for elective cardioversion

This prospective, randomized, double-blind study was designed to compare the recovery characteristics of remifentanil and fentanyl in combination with propofol for direct current cardioversion. Patients undergoing elective cardioversion received either intravenous fentanyl 1 microg/kg (n=33) or remifentanil 0.25 microg/kg (n=30) and propofol was titrated to a Ramsay sedation score of 5 by slow intravenous injection. Heart rate, systolic, diastolic and mean blood pressures decreased significantly following sedation in both groups but did not show a significant difference between the groups. Time to answer a question (306 +/- 83 vs 383 +/- 131s, mean +/- SD, P=0.014) and time to sit up (412 +/- 90 vs 511 +/- 126s, P=0.002) were significantly shorter in the remifentanil group compared to the fentanyl group. Side-effects and patient discomfort were similar for both groups. Remifentanil can be used as a suitable supplement to propofol for direct current cardioversion and may provide a faster recovery profile than fentanyl.