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

Efficacy, safety, and pharmacokinetics of MR13A11A, a generic of remifentanil, for pain management of Japanese patients in the intensive care unit: a double-blinded, fentanyl-controlled, randomized, non-inferiority phase 3 study

BACKGROUND

The aims of this study were to evaluate the efficacy, safety, and pharmacokinetics (PK) of continuous intravenous administration of remifentanil in mechanically ventilated patients in the intensive care unit (ICU).

METHODS

This was a multicenter, randomized, double-blinded, fentanyl-controlled, non-inferiority phase 3 study. Patients aged ≥ 20 years requiring 6 h to 10 days mechanical ventilation in an ICU and requiring pain relief were randomly assigned in a 1:1 ratio to receive either remifentanil (n = 98) or fentanyl (n = 98). Dose was titrated from an infusion rate of 1 mL/h (remifentanil: 0.025 µg/kg/min, fentanyl: 0.1 µg/kg/h) until the target level of analgesia (behavioral pain scale [BPS] ≤ 5 or numerical rating score [NRS] ≤ 3) was achieved by escalating the dose in 1 mL/h increasing. Administration was then adjusted to maintain the target level of analgesia until weaning from the ventilator. The primary endpoint was the proportion of patients who did not require rescue fentanyl. Safety was assessed according to standard procedures. PK of remifentanil in the arterial blood was assessed in 24 patients.

RESULTS

The proportion of patients achieving the primary endpoint in the remifentanil and fentanyl groups was 100% (92/92) and 97.8% (88/90), respectively. The difference between the groups was 2.2% (95% confidence interval, - 0.8-5.3) and non-inferiority of remifentanil to fentanyl was verified (p < 0.0001). The incidences of any adverse events in the remifentanil and fentanyl groups was 34 of 92 patients (37.0%) and 34 of 90 patients (37.8%), respectively. Adverse drug reactions was 12 in 92 patients (13.0%) and 15 in 90 patients (16.7%), respectively. In the PK analysis, blood remifentanil concentration decreased within 10 min to almost 50% of the end of administration, suggesting rapid offset of action following discontinuation of remifentanil.

CONCLUSIONS

Remifentanil can be used safely for pain management in mechanically ventilated Japanese patients in the ICU.

TRIAL REGISTRATION

Japan Registry of Clinical Trials, jRCT2080224954. Registered 20 November 2019, https://jrct.niph.go.jp/latest-detail/jRCT2080224954 .

The Global States and Hotspots of ERAS Research From 2000 to 2020: A Bibliometric and Visualized Study

Background

Enhanced recovery after surgery (ERAS) protocol has been implemented in surgeries for more than 20 years, this study investigated the global states and hotspots of ERAS research.

Methods

Based on the Web of Science database, a bibliometric and visualized study of original ERAS research from 2000 to 2020 was performed, including the trends of publications and citations; distribution of countries, authors, institutions, sources; study design, level of evidence, served surgeries and surgical disciplines. Hotspots were revealed by research interests and keywords.

Results

Within the field of original ERAS research, there was a rising trend in annual publications and citations. The USA was the greatest contributor. Kehlet, H, University of Copenhagen were the most influential author and institution, respectively. British Journal of Surgery and Annals of Surgery were the most cited journals. Though there were more prospective designs, more than half of the studies presented level IV evidence and had fewer citations and citation densities compared to that of level II and level III. ERAS protocol was overwhelmingly implemented in colorectal surgeries. Most studies focused on elements of ERAS, the top three research interests were “length of stay,” “pain management,” and “complications.” In recent years, bariatric surgery, compliance with ERAS, and feasibility in the elderly were new hotspots.

Conclusion

Revealing the global states and hotspots can help researchers better understand the trends in ERAS research. The USA was the greatest contributor to ERAS research. Kehlet, H, was the most influential author in the field. Bariatric surgery, compliance with ERAS, and feasibility in the elderly represent the new trend of ERAS research. Most of the ERAS research had a low evidence levels, studies with high-level evidence are still required in this field.

Comparison of the cardioprotective effects of dexmedetomidineand remifentanil in cardiac surgery

Background/aim: Myocardial protection is an important factor of open heart surgery and biological biomarkers (lactate, CKMB, cardiac troponin I, and pyruvate) are used to assess myocardial damage. This study compares the effects of dexmedetomidine and remifentanil on myocardial protection during coronary artery bypass grafting (CABG) surgery. Materials and methods: Patients scheduled for elective CABG surgery (n = 60) were included in this study. Anesthesia induction was introduced with propofol, fentanyl, and vecuronium bromide. Anesthesia was maintained with remifentanil infusion and sevoflurane in the remifentanil group (Group R) and with dexmedetomidine infusion and sevoflurane in the dexmedetomidine group (Group D). Blood samples for biochemical markers were taken from the coronary sinus catheter before cardiopulmonary bypass (T1), 20 min after aortic cross-clamping (T2), 20 min after removal of the aortic cross-clamping (T3), and 10 min after separation from cardiopulmonary bypass (T4).Results: Demographic data were similar between the groups. Lactate level at the T2 period and CKMB levels during the study period were lower in Group D than in Group R. In both groups, all values except pyruvate significantly increased over time. Conclusion: The dexmedetomidine-sevoflurane combination may improve the cardioprotective effect in comparison with remifentanil-sevoflurane in CABG surgery.

Comparison of the Effect of Anesthesia With Midazolam-Fentanyl Versus Propofol-Remifentanil on Bispectral Index in Patients Undergoing Coronary Artery Bypass Graft

The aim of this study was to compare the effect of anesthesia with midazolam-fentanyl versus propofol-remifentanil on the BIS (bispectral index) in patients undergoing coronary artery bypass grafting (CABG). Sixty-four patients undergoing CABG were randomly assigned to one of two study groups: midazolam-fentanyl (MF, N= 32) or propofol-remifentanil (PR, N= 32). The BIS was measured before induction of anesthesia, five minutes after induction of anesthesia, at skin incision, sternotomy, pericardiotomy, aorta cannulation, onset of cardiopulmonary bypass, during rewarming, five minutes after separation from cardiopulmonary bypass, at thorax closure, and at the end of the surgery. There were no significant differences between the two groups with regard to age and gender. The difference in mean BIS between the two groups was significant (P < 0.05) at all times, except before induction, five minutes after induction, at skin incision and on rewarming. Changes in the BIS were lower in the PR group than in the MF group. Both techniques can provide adequate anesthesia in patients undergoing CABG. However, the probability of awareness during anesthesia is lower with propofol-remifentanil than with midazolam-fentanyl.

Fast-track practice in cardiac surgery: results and predictors of outcome

OBJECTIVES

Various studies have shown different parameters as independent risk factors in predicting the success of fast-track postoperative management in cardiac surgery. In the present study, we evaluated our 7-year experience with the fast-track protocol and investigated the preoperative predictors of successful outcome.

METHODS

Between 2004 and 2010, 5367 consecutive patients undergoing cardiac surgery were preoperatively selected for postoperative admission in the postanaesthesia care unit (PACU) and were included in this study. These patients were then transferred to the ordinary ward on the same day of the operation. The primary end-point of the study was the success of the PACU protocol, defined as discharge to the ward on the same day, no further admission to the intensive care unit and no operative mortality. Logistic regression analysis was performed to detect the independent risk factors for failure of the PACU pathway.

RESULTS

Of 11,895 patients undergoing cardiac surgery, 5367 (45.2%) were postoperatively admitted to the PACU. The protocol was successful in 4510 patients (84.0%). Using the multivariate logistic regression analysis, older age and left ventricular dysfunction were found to be independent risk factors for failure of the PACU protocol [odds ratio of 0.98/year (0.97-0.98) and 0.31 (0.14-0.70), respectively].

CONCLUSIONS

Our fast-track management, called the PACU protocol, is efficient and safe for the postoperative management of selected patients undergoing cardiac surgery. Age and left ventricular dysfunction are significant preoperative predictors of failure of this protocol.

Remifentanil in cardiac surgery: a meta-analysis of randomized controlled trials

OBJECTIVE

The authors conducted a review of randomized controlled trials to identify advantages in clinically relevant outcomes in patients undergoing cardiac surgery with remifentanil.

DESIGN

Meta-analysis.

SETTING

Hospitals.

PARTICIPANTS

A total of 1,473 patients from 16 randomized trials.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULT

PubMed, BioMedCentral, and conference proceedings were searched (updated May 2010) for randomized trials that compared remifentanil with fentanyl or sufentanil in cardiac anesthesia. Four independent reviewers performed data extraction, with divergences resolved by consensus. Overall analysis showed that the use of remifentanil was associated with a significant reduction in postoperative mechanical ventilation (WMD = -139 min [-244, -32], p for effect = 0.01, p for heterogeneity < 0.001, I(2) = 89%); length of hospital stay (WMD = -1.08 days [-1.60, -0.57], p for effect < 0.0001, p for heterogeneity = 0.004, I(2) = 71%); and cardiac troponin-I release (WMD = -2.08 ng/mL [-3.93, -0.24], p for effect = 0.03, p for heterogeneity < 0.02, I(2) = 74%). No difference was noted in mortality (3/344 [0.87%] in the remifentanil group vs [1.06%] the control group, OR 0.76 [0.17-3.38], p for effect = 0.72, p for heterogeneity = 0.35, I(2) = 5%).

CONCLUSIONS

Remifentanil reduces cardiac troponin release, time of mechanical ventilation, and length of hospital stay in patients undergoing cardiac surgery.

Health-related quality of life after fast-track treatment results from a randomized controlled clinical equivalence trial

PURPOSE

This randomized clinical equivalence trial was designed to evaluate health-related quality of life (HRQoL) after fast-track treatment for low-risk coronary artery bypass (CABG) patients.

METHODS

Four hundred and ten CABG patients were randomly assigned to undergo either short-stay intensive care treatment (SSIC, 8 h of intensive care stay) or control treatment (care as usual, overnight intensive care stay). HRQoL was measured at baseline and 1 month, and one year after surgery using the multidimensional index of life quality (MILQ), the EQ-5D, the Beck Depression Inventory and the State-Trait Anxiety Inventory.

RESULTS

At one month after surgery, no statistically significant difference in overall HRQoL was found (MILQ-score P-value=.508, overall MILQ-index P-value=.543, EQ-5D VAS P-value=.593). The scores on the MILQ-domains, physical, and social functioning were significantly higher at one month postoperatively in the SSIC group compared to the control group (P-value=.049; 95%CI: 0.01-2.50 and P-value=.014, 95% CI: 0.24-2.06, respectively). However, these differences were no longer observed at long-term follow-up.

CONCLUSIONS

According to our definition of clinical equivalence, the HRQoL of SSIC patients is similar to patients receiving care as usual. Since safety and the financial benefits of this intervention were demonstrated in a previously reported analysis, SSIC can be considered as an adequate fast-track intensive care treatment option for low-risk CABG patients.

Remifentanil versus fentanyl compared in a target-controlled infusion of propofol anesthesia: quality of anesthesia and recovery profile

PURPOSE

The aim of the present study was to compare the clinical properties of fentanyl versus remifentanil in a target-controlled infusion (TCI) of propofol anesthesia regimen with bispectral index (BIS) monitoring.

METHODS

Forty consenting patients scheduled for elective septorhinoplasty were prospectively studied as one of two groups: fentanyl (group F) or remifentanil (group R). After loading boluses of fentanyl 3 microg kg(-1) or remifentanil 1 microg kg(-1) were administered, the continuous infusion of fentanyl or remifentanil was started at a rate of 0.03 or 0.15 microg kg(-1) min(-1), respectively. Propofol infusion was then commenced with a 3 microg ml(-1) effect site concentration (Ce) by means of a TCI device. The Ce propofol was adjusted to keep BIS at 50 +/- 10.

RESULTS

The general mean value of propofol Ce for group F and group R was 4.0 and 3.5 microg ml(-1), respectively. As to the recovery profile, the eye opening time (mean, 6.7 vs. 4.6 min), extubation time (mean, 7.3 vs. 4.7 min), and orientation time (mean, 7.6 vs. 4.9 min) were found to be significantly longer in group F than in group R.

CONCLUSION

We concluded that in propofol-based TCI anesthesia under BIS supervision for septorhinoplasty operations, remifentanil was better than fentanyl, especially with respect to emergence from total intravenous anesthesia (TIVA). Furthermore, the durations of anesthesia and operation were rather short, which indicates that fentanyl can be safely used.

Factors that influence awakening in coronary artery bypass graft using propofol and remifentanil

BACKGROUND

The development of total intravenous anesthesia in coronary artery bypass graft (CABG) surgery has led to increased interest in the use of combination of propofol and remifentanil. Early extubation in post-cardiac surgery reduces the length of stay in intensive care unit and hospital and costs. The purpose of this study is to evaluate which anesthetic factors affect awakening time after anesthesia.

METHODS

We enrolled twenty patients of ASA physical status II or III, scheduled for CABG in this study. All patients received a standardized propofol/remifentanil anesthesia as an effect site target controlled infusion. We recorded times to awakening and tracheal extubation, duration of cardiopulmonary bypass (CPB) period, total time of anesthesia and operation. Also, we recorded dose of propofol, remifentanil, fentanyl and minimum body temperature during CPB. To predict the factors that affect awakening time as a dependent variable, we considered all measured parameters as independent variables, and analyzed multiple linear regressions.

RESULTS

The mean time responded to verbal command was 216.5 +/- 124.8 minutes after end of surgery. Among several parameters, minimum body temperature during CPB (P = 0.001) and total time of anesthesia (P = 0.003) were considered as significant factors that influence awakening time after CABG.

CONCLUSIONS

Minimum body temperature during CPB and the duration of anesthesia influence awakening time after CABG, significantly.

Remifentanil for general anaesthesia: a systematic review

We performed a quantitative systematic review of randomised, controlled trials that compared remifentanil to short-acting opioids (fentanyl, alfentanil, or sufentanil) for general anaesthesia. Eighty-five trials were identified and these included a total of 13 057 patients. Intra-operatively, remifentanil was associated with clinical signs of deeper analgesia and anaesthesia, such as fewer responses to noxious stimuli (relative risk 0.65, 95% CI 0.48-0.87), more frequent episodes of bradycardia (1.46, 1.04-2.05), more hypotension (1.68, 1.36-2.07) and less hypertension (0.60, 0.46-0.78). Postoperatively, remifentanil was associated with faster recovery (difference in extubation time of -2.03, 9.5% CI, -2.92 to -1.14 min), more frequent postoperative analgesic requirements (1.36, 1.21-1.53) and fewer respiratory events requiring naloxone (0.25, 0.14-0.47). Remifentanil had no overall impact on postoperative nausea (1.03, 0.97-1.09) or vomiting (1.06, 0.96-1.17), but was associated with twice as much shivering (2.15, 1.73-2.69). Remifentanil does not seem to offer any advantage for lengthy, major interventions, but may be useful for selected patients, e.g. when postoperative respiratory depression is a concern.

The isoflurane-sparing and clinical effects of a constant rate infusion of remifentanil in dogs

OBJECTIVE

To evaluate the isoflurane-sparing and clinical effects of two constant rate infusions of remifentanil in healthy dogs undergoing orthopaedic surgery.

STUDY DESIGN

Prospective, randomized clinical study.

ANIMALS

Forty-one American Society of Anesthesiologists I-II client-owned dogs (age, 7 months-9 years; body mass 11-59 kg).

METHODS

Dogs were randomly assigned to one of three groups and received either: intramuscular (IM) meperidine 2 mg kg(-1) every 2 hours throughout surgery (control group (C); n = 13); remifentanil infused intravenously (IV) at 0.1 microg kg(-1) minute(-1) (low remifentanil group (L); n = 14) or remifentanil infused at 0.25 microg kg(-1) minute(-1) IV (high remifentanil group (H); n = 14). Anaesthesia was induced with thiopental administered to effect and maintained using isoflurane in 100% oxygen. During controlled ventilation when the end-tidal CO(2) was maintained between 4.65 and 5.98 kPa [35-45 mmHg], the end-tidal isoflurane concentration (e'iso%), mean arterial blood pressure (MAP) and heart rate (HR) were measured every 5 minutes. Bradycardia (HR < 40 minute(-1) lasting >5 minutes) was corrected with 0.01 mg kg(-1) IV glycopyrrolate. Data were analysed using the Kruskal-Wallis test with a post-hoc Mann-Whitney U-test and Bonferroni correction. Statistical significance was accepted at < or = 0.05. Data are expressed as mean +/- standard deviation.

RESULTS

The e'iso% was reduced in a dose-dependent manner by remifentanil. In C, e'iso% was 1.28 +/-0.13 and was significantly different from L (0.78 +/- 0.17, p < 0.001) and H (0.65 +/- 0.16, p < 0.001). HR was significantly different between groups (p < 0.001). There were no significant differences in MAP between groups. Glycopyrrolate was required in two, three and six dogs in the C, L and H groups respectively.

CONCLUSIONS

Remifentanil infusion reduced the isoflurane concentration required for surgical anaesthesia during orthopaedic surgery.

CLINICAL RELEVANCE

Remifentanil infusions may be a useful additive to isoflurane anaesthesia in healthy dogs.

Fast-Track Cardiac Anesthesia: Efficacy and Safety of Remifentanil Versus Sufentanil

OBJECTIVE

The purpose of this study was to compare the safety and efficacy of fast-track cardiac anesthesia with remifentanil (group R) versus sufentanil (group S).

DESIGN

Prospective, single-blinded, randomized study.

SETTING

University hospital.

PARTICIPANTS

One hundred twenty patients undergoing coronary artery bypass graft surgery and/or cardiac valve surgery.

INTERVENTIONS

After routine standardized anesthesia induction, anesthesia was maintained with isoflurane (0.4-0.8 vol%) together with either remifentanil (group R) (1 microg/kg/min) or sufentanil (group S) (1 microg/kg for induction, 0.5 microg/kg for skin incision, and then 0.02 microg/kg/min). After surgery, which included cardiopulmonary bypass in all cases, postoperative sedation was achieved in both groups with propofol until the patient was deemed ready for extubation. Additionally, patients in group R received remifentanil, 0.25 microg/kg/min.

MEASUREMENTS AND MAIN RESULTS

Recovery profile in group R patients was faster (p < 0.05), with a median time interval between end of surgery and eligibility for extubation of 295 minutes versus 375 minutes. Time from end of surgery to being eligible for discharge from intensive care unit was similar in both groups, with 22.9 hours in group R versus 26.3 hour in group S. Remifentanil provided a better protection against intraoperative stimuli at skin incision and maximal sternal spread (p < 0.05). The incidence of adverse events was comparable in both groups. Postoperative pain scores during the first hour of weaning were higher in group R (p < 0.05).

CONCLUSIONS

Remifentanil for fast-track cardiac anesthesia provided safe and stable operating conditions and facilitated earlier tracheal extubation. However, postoperative pain management should be planned carefully.

Comparison of the effects of fentanyl and remifentanil on splanchnic tissue perfusion during cardiac surgery

The purpose of this study was to compare the effects of fentanyl and remifentanil on splanchnic perfusion during coronary artery bypass graft (CABG) surgery. Fifty patients were randomized to receive either fentanyl (10 microgxkg(-1) at induction and 5 microgxkg(-1)xh(-1) infusion for maintenance) or remifentanil (3 microgxkg(-1) at induction and 1 microgxkg(-1)xmin(-1) infusion for maintenance). Patients in both groups were comparable with regard to demographics. Intraoperative volume management and inotropic therapy were similiar in both groups. Regarding heart rate, there were no significant differences between the groups at any measurement time (P > 0.05). Compared to the fentanyl group, the remifentanil group showed a significant decrease in mean arterial pressure during induction. Also, the gastric intramucosal CO(2) pressure (Pg(CO) (2)) and the P(CO) (2)-gap, defined as the difference between Pg(CO) (2) and Pa(CO) (2), were significantly increased and the gastric mucosal pH (pHi) was significantly decreased in the remifentanil group in the postinduction period (P < 0.05). However, there were no statistically significant differences in respiratory data at any time between the two groups (P > 0.05). Both fentanyl and remifentanil seemed to be effective and well tolerated in this CABG population. Episodes of hypotension and transient reduction in splanchnic perfusion were more common in patients treated with remifentanil when compared to those receiving the fentanyl opioid regimen.

Extubation time, hemodynamic stability, and postoperative pain control in patients undergoing coronary artery bypass surgery: an evaluation of fentanyl, remifentanil, and nonsteroidal antiinflammatory drugs with propofol for perioperative and postoperative management

STUDY OBJECTIVE

To compare three anesthetic strategies with respect to the time of extubation after coronary artery bypass graft (CABG) surgery and to assess patient satisfaction with the procedure.

DESIGN

Prospective, randomized, clinical study.

SETTING

Tertiary-care referral center.

PARTICIPANTS

180 cardiac surgical patients undergoing primary CABG from January through June 2004.

INTERVENTIONS

After induction of general anesthesia, patients were allocated to one of three groups. All three groups received a continuous infusion of intravenous (IV) propofol perioperatively and postoperatively. Group 1 (fentanyl infusion group, n = 60) received continuous IV fentanyl infusion perioperatively and postoperatively for analgesia. Group 2 (diclofenac group, n = 60) received fentanyl bolus doses intraoperatively and diclofenac suppository postoperatively. Group 3 (remifentanil group, n = 60) received continuous infusion of IV remifentanil perioperatively and IV fentanyl as an immediate postoperative bolus followed by continuous fentanyl infusion. Duration of postoperative ventilation up to the time of extubation, inotrope requirement, time at which analgesic infusion was discontinued, postextubation arterial blood gas analysis, pain evaluation via visual analog scale, need for rescue analgesia, awareness during surgery, and length of postcardiac surgical unit stay, were evaluated in each patient.

MAIN RESULTS

The diclofenac group exhibited the shortest time to extubation, the least inotrope use, and the fewest rescue doses of analgesic than did patients of the other two groups.

CONCLUSION

Intravenous propofol with bolus doses of IV fentanyl intraoperatively in combination with postoperative nonsteroidal antiinflammatory drugs had the best recovery profile in patients undergoing primary CABG than did the other two regimens studied.

Spotlight on remifentanil: its analgesic and sedative use in the intensive care unit

Remifentanil (Ultivatrade), a 4-anilidopiperidine derivative of fentanyl, is an ultra-short-acting micro-opioid receptor agonist indicated to provide analgesia and sedation in mechanically ventilated intensive care unit (ICU) patients. Analgesia-based sedation with remifentanil is a useful option for mechanically ventilated patients in the ICU setting. Its unique properties (e.g. organ-independent metabolism, lack of accumulation, rapid offset of action) set it apart from other opioid agents. Remifentanil is at least as effective as comparator opioids such as fentanyl, morphine and sufentanil in providing pain relief and sedation in mechanically ventilated ICU patients. Moreover, it allows fast and predictable extubation, as well as being associated with a shorter duration of mechanical ventilation and quicker ICU discharge than comparators in some studies. In addition, remifentanil is generally well tolerated in this patient population. Thus, remifentanil is a welcome addition to the currently available pharmacological agents employed in the management of mechanically ventilated ICU patients.

Does fast-track treatment lead to a decrease of intensive care unit and hospital length of stay in coronary artery bypass patients? A meta-regression of randomized clinical trials*

OBJECTIVE

Evaluation of randomized, controlled clinical trials studying fast-track treatment in low-risk coronary artery bypass grafting patients.

DESIGN

Meta-regression.

PATIENTS

Low-risk coronary artery bypass grafting patients.

INTERVENTIONS

Fast-track treatments including (high or low) anesthetic dose, normothermia vs. hypothermia, and extubation protocol (within or after 8 hrs).

MEASUREMENTS

Number of hours of intensive care unit stay, number of days of hospital stay, prevalence of myocardial infarction, and death. Furthermore, quality of life and cost evaluations were evaluated. The epidemiologic and economic qualities of the different trials were also assessed.

MAIN RESULTS

A total of 27 studies evaluating fast-track treatment were identified, of which 12 studies were with major and 15 were without major differences in extubation protocol or anesthetic treatment or both. The use of an early extubation protocol (p=.000) but not the use of a low anesthetic dose (p=.394) or normothermic temperature management (p=.552) resulted in a decrease of the total intensive care unit stay of low-risk coronary artery bypass grafting patients. Early extubation was found to be an important determinant of the total hospital stay for these patients. An influence of the type of fast-track treatment on mortality or the prevalence of postoperative myocardial infarction was not observed. In general, the epidemiologic and economic qualities of included studies were moderate.

CONCLUSIONS

Although fast-track anesthetics and normothermic temperature management facilitate early extubation, the introduction of an early extubation protocol seems essential to decrease intensive care unit and hospital stay in low-risk coronary artery bypass grafting patients.

Remifentanil

Remifentanil (Ultiva), a 4-anilidopiperidine derivative of fentanyl, is an ultra-short-acting micro-opioid receptor agonist indicated to provide analgesia and sedation in mechanically ventilated intensive care unit (ICU) patients.Analgesia-based sedation with remifentanil is a useful option for mechanically ventilated patients in the ICU setting. Its unique properties (e.g. organ-independent metabolism, lack of accumulation, rapid offset of action) set it apart from other opioid agents. Remifentanil is at least as effective as comparator opioids such as fentanyl, morphine and sufentanil in providing pain relief and sedation in mechanically ventilated ICU patients. Moreover, it allows fast and predictable extubation, as well as being associated with a shorter duration of mechanical ventilation and quicker ICU discharge than comparators in some studies. In addition, remifentanil is generally well tolerated in this patient population. Thus, remifentanil is a welcome addition to the currently available pharmacological agents employed in the management of mechanically ventilated ICU patients.

Remifentanil infusion in association with fentanyl–propofol anaesthesia in patients undergoing cardiac surgery: effects on morphine requirement and postoperative analgesia

BACKGROUND

We have prospectively assessed the effects of remifentanil on morphine requirement in the first hour after emerging from general anaesthesia after elective coronary artery bypass surgery and in the first 12 h postoperatively, and pain and agitation scores in the first hour after emerging from general anaesthesia.

METHODS

Twenty patients undergoing off-pump coronary artery bypass surgery, receiving standardized propofol-fentanyl-based anaesthesia, randomly received infusions of either remifentanil 0.1 microg kg(-1) min(-1) (Group R, n=10) or saline (Group S, n=10), each infused at 0.12 ml kg(-1) h(-1). Propofol and trial drug infusion were continued into the postoperative period until the patients were ready to be woken up. Postoperative analgesia was provided with morphine infusion commenced immediately after operation, and was additionally nurse controlled on the basis of a visual analogue scale (VAS) score (0-10). Agitation score was recorded using a VAS of 0-3.

RESULTS

In the first hour after discontinuing propofol and trial infusion, morphine requirements were significantly higher in the remifentanil group (8.15 (sd 3.59) mg) compared with the saline group (3.29 (2.36) mg) (P<0.01). There was no difference in the total morphine given during the period after stopping propofol or in the total requirement in the first 12 h postoperatively. There was no significant difference in either pain scores or agitation scores between the two groups.

CONCLUSION

Use of remifentanil is associated with increased opioid requirement in the first hour after it has been discontinued.

Postoperative Analgesia After Spinal Blockade in Infants and Children Undergoing Cardiac Surgery

The aim of this prospective, randomized, controlled clinical trial was to define the opioid analgesic requirement after a remifentanil (REMI)-based anesthetic with spinal anesthetic blockade (SAB+REMI) or without (REMI) spinal blockade for open-heart surgery in children. We enrolled 45 patients who were candidates for tracheal extubation in the operating room after cardiac surgery. Exclusion criteria included age <3 mo and >6 yr, pulmonary hypertension, congestive heart failure, contraindication to SAB, and failure to obtain informed consent. All patients had an inhaled induction with sevoflurane and maintenance of anesthesia with REMI and isoflurane (0.3% end-tidal). In addition, patients assigned to the SAB+REMI group received SAB with tetracaine (0.5-2.0 mg/kg) and morphine (7 mug/kg). After tracheal extubation in the operating room, patients received fentanyl 0.3 mug/kg IV every 10 min by patient-controlled analgesia for pain score = 4. Pain scores and fentanyl doses were recorded every hour for 24 h or until the patient was ready for discharge from the intensive care unit. Patients in the SAB+REMI group had significantly lower pain scores (P = 0.046 for the first 8 h; P =0.05 for 24 h) and received less IV fentanyl (P = 0.003 for the first 8 h; P = 0.004 for 24 h) than those in the REMI group. There were no intergroup differences in adverse effects, including hypotension, bradycardia, highest PaCO(2), lowest pH, episodes of oxygen desaturation, pruritus, and vomiting.

Fast-track coronary artery bypass grafting surgery under general anesthesia with remifentanil and spinal analgesia with morphine and clonidine

OBJECTIVE

Effective postoperative analgesia is a critical part of fast-track cardiac surgery. This study compared the postoperative analgesic effect of fast-track anesthesia with remifentanil and spinal morphine and clonidine with that of sufentanil anesthesia followed by patient-controlled administration of intravenous morphine.

DESIGN

Prospective, blinded, randomized study.

SETTING

Single private institution.

PARTICIPANTS

Forty patients selected for coronary artery bypass graft surgery allocated randomly into 2 groups.

INTERVENTIONS

General anesthesia was performed with etomidate, isoflurane, cisatracurium, and either remifentanil (0.10-0.25 microg/kg/min) or sufentanil (up to 3.5 microg/kg). In the remifentanil group, patients received spinal morphine (4 microg/kg) and clonidine (1 microg/kg) before induction. Postoperatively, patients in both groups were connected to an intravenous patient-controlled analgesia (PCA) morphine pump that delivered a 1-g bolus with a 7-minute lockout interval.

MEASUREMENTS AND MAIN RESULTS

Patients were evaluated for pain on a visual analog scale (VAS), at rest and on deep breathing, and for intravenous PCA morphine consumption during 24 hours. The intravenous PCA morphine 24-hour cumulative dose was lower in the fast-track than in the control group (15.8+/-12.6 v 32.7+/-22.3 mg, p<0.05). Before extubation, VAS scores were higher in the fast-track group, but after they were lower both at rest and during deep breathing. Extubation delay was shorter in the fast-track group (156.5+/-46.1 v 272+/-116.4 minutes, p<0.05).

CONCLUSION

The combination of anesthesia with remifentanil and spinal analgesia with morphine and clonidine produces effective analgesia after coronary artery surgery and a rapid extubation time.

Remifentanil

Remifentanil (Ultiva), a fentanyl derivative, is an ultra-short acting, nonspecific esterase-metabolised, selective mu-opioid receptor agonist, with a pharmacodynamic profile typical of opioid analgesic agents. Notably, the esterase linkage in remifentanil results in a unique and favourable pharmacokinetic profile for this class of agent. Adjunctive intravenous remifentanil during general anaesthesia is an effective and generally well tolerated opioid analgesic in a broad spectrum of patients, including adults and paediatric patients, undergoing several types of surgical procedures in both the inpatient and outpatient setting. Remifentanil is efficacious in combination with intravenous or volatile hypnotic agents, with these regimens generally being at least as effective as fentanyl- or alfentanil-containing regimens in terms of attenuation of haemodynamic, autonomic and somatic intraoperative responses, and postoperative recovery parameters. The rapid offset of action and short context-sensitive half-time of remifentanil, irrespective of the duration of the infusion, makes the drug a valuable opioid analgesic option for use during balanced general inhalational or total intravenous anaesthesia (TIVA) where rapid, titratable, intense analgesia of variable duration, and a fast and predictable recovery are required.

Supplemental remifentanil during coronary artery bypass grafting is followed by a transient postoperative cardiac depression

BACKGROUND

The pharmacokinetic properties of the short-acting micro opioid receptor-agonist remifentanil makes it possible to give cardiac surgical patients a deep intraoperative anesthesia without experiencing postoperative respiratory depression and a prolonged stay in the intensive care unit (ICU). However, previous investigations have shown that patients who received remifentanil required additional analgesia during the early postoperative period as compared to patients who received fentanyl. The aim of the present study therefore was to investigate the effects of supplementing remifentanil to a standard fentanyl-based anesthesia in coronary artery bypass grafting (CABG).

METHODS

The study was prospective, randomized, double-blind, and placebo-controlled. Twenty male patients aged 55-70 years were included. All patients received a standard fentanyl and isoflurane-based anesthesia. In addition, the patients were randomized to receive either remifentanil 0.5 micro g kg(-1) min(-1) or placebo during surgery. Hemodynamic recordings and measurements of blood glucose and plasma adrenaline and noradrenaline were performed intra- and postoperatively.

RESULTS

Remifentanil reduced the hemodynamic and metabolic response to surgical stress compared to the standard fentanyl-based anesthetic regimen. However, the patients in the remifentanil group had a lower cardiac output (CO), left ventricular stroke work index (LVSWI), and mixed venous oxygen saturation (SvO(2)), and a higher central venous pressure (CVP) than the patients in the placebo group during the early postoperative phase, indicating a postoperative cardiac depression in the remifentanil group.

CONCLUSION

In CABG, remifentanil reduces the hemodynamic and metabolic responses during surgery but seems to give a cardiac depression in the early postoperative phase.

A randomised controlled trial comparing remifentanil and fentanyl for induction of anaesthesia in CABG surgery

INTRODUCTION

In a prospective randomised trial we studied haemodynamic stability during induction of anaesthesia for CABG surgery in patients receiving remifentanil-propofol or fentanyl-propofol anaesthesia.

METHODS

Fifty-four patients scheduled for elective CABG surgery were studied. Anaesthesia was induced with propofol and pancuronium. The patients were randomly assigned to two groups according to the opioid used during the induction. The remifentanil group received 0.5 microg kg(-1) min(-1) of the drug and the fentanyl group received 5 microg kg(-1). We measured blood pressure, central venous pressure and heart rate continuously for 15 min before and 30 min after orotracheal intubation. We also recorded use of rescue medication for maintaining the mean arterial pressure between 65 and 85 mmHg.

RESULTS

After induction of anaesthesia the mean arterial pressure and heart rate decreased significantly in both groups (P<0.05). After orotracheal intubation the mean arterial pressure and heart rate increased significantly in the fentanyl group but not in the remifentanil group (P<0.05). The incidence of hypertonic events necessitating the use of rescue medication was significantly higher in the fentanyl group (P<0.05).

CONCLUSIONS

Our results show more stable haemodynamics after induction of anaesthesia in CABG surgery in patients receiving remifentanil-propofol than in patients receiving fentanyl-propofol.

Comparison of bolus remifentanil versus bolus fentanyl for induction of anesthesia and tracheal intubation in patients with cardiac disease

OBJECTIVE

Large bolus-dose remifentanil may be advantageous for use during induction of anesthesia because of its short duration of effect. Currently, there are little data on the use of large bolus-dose remifentanil because of reports of severe bradycardia and hypotension. The purpose of this study is to compare the hemodynamic effects of bolus remifentanil versus fentanyl with glycopyrrolate for induction of anesthesia in patients with heart disease.

DESIGN

A randomized, double-blinded study.

SETTING

A tertiary-care academic medical center.

PARTICIPANTS

One hundred patients for coronary artery bypass or valvular surgery.

INTERVENTION

Subjects received either (1) remifentanil, 5 microg/kg, with glycopyrrolate, 0.2 mg, or (2) fentanyl, 20 microg/kg, with 0.2 mg of glycopyrrolate, and both groups also received midazolam, 70 microg/kg, for induction of anesthesia.

MEASUREMENTS AND MAIN RESULTS

Heart rate, mean arterial pressure, systemic vascular resistance, and cardiac output were similar between the 2 groups during induction of anesthesia and tracheal intubation. The incidence of adverse events such as bradycardia (remifentanil 10%, fentanyl 10%), hypotension (remifentanil 16%, fentanyl 10%), and ischemia (remifentanil 0%, fentanyl 2%) were also similar. A greater percentage of patients in the remifentanil group lost consciousness within 1 minute of opioid administration (86% v 66%, p = 0.034).

CONCLUSION

Remifentanil with glycopyrrolate is associated with rapid and predictable clinical anesthetic effect, cardiac stability, and the ability to blunt the hemodynamic responses to tracheal intubation. Bolus remifentanil may be a feasible alternative to bolus fentanyl for induction of anesthesia in patients with heart disease because of its short duration of action and its ability to blunt the hemodynamic responses to tracheal intubation.

Clinical experience with adaptive support ventilation for fast-track cardiac surgery

OBJECTIVE

To evaluate adaptive support ventilation (ASV), an automatic microprocessor-controlled mode of mechanical ventilation, for the initial ventilatory management in consecutive patients eligible for early extubation after cardiac surgery.

DESIGN

Prospective observational study.

SETTING

Nonuniversity cardiac center.

PARTICIPANTS

One hundred fifty-five consecutive patients eligible for early tracheal extubation after cardiac surgery.

INTERVENTIONS

On intensive care unit arrival, patients were ventilated by adaptive support ventilation. This mode provided an automatic selection of initial ventilatory parameters and a continuous adaptation to patient's respiratory activity, guaranteeing that a preset minute ventilation was delivered. Once the patients had recovered sustained spontaneous ventilation, the ventilator was switched manually to pressure support for the terminal part of respiratory weaning followed by extubation.

MEASUREMENTS AND MAIN RESULTS

In adaptive support ventilation, all patients could be ventilated satisfactorily except 1; tidal volume was 8.7 +/- 1.4 mL/kg of ideal body weight (mean +/- SD), plateau pressure was 20.3 +/- 3.9 cmH(2)O, and arterial blood gas measurements were satisfactory. One hundred thirty-four patients (86%) were extubated within 6 hours, and intubation time was 3.6 (2.53-4.83) hours (median, [quartiles]). No reintubation because of respiratory failure was required. Adaptive support ventilation was considered easy to use by both the nurses and physicians.

CONCLUSIONS

Adaptive support ventilation was used in a group of 155 consecutive patients after fast-track cardiac surgery. This ventilation mode was safe, easy to apply, and allowed rapid extubation in suitable patients. ASV may facilitate postoperative respiratory management.

Comparison of three remifentanil dose-finding regimens for coronary artery surgery

OBJECTIVES

To identify the remifentanil dosing regimen providing safe and optimal anesthetic conditions during coronary artery bypass graft surgery and to evaluate postoperative recovery characteristics.

DESIGN

Open-label, randomized, parallel group.

SETTING

Three centers in the United States.

PARTICIPANTS

Seventy-two patients with left ventricular stroke volumes >or=50 mL.

INTERVENTIONS

Patients were randomized to remifentanil doses of 1 microg/kg/min (group 1, n = 23); 2 microg/kg/min (group 2, n = 24), or 3 microg/kg/min (group 3, n = 25). Somatic, sympathetic, and hemodynamic responses indicating inadequate anesthesia were treated with bolus doses of remifentanil, 1 to 2 microg/kg, and infusion rate increases, and, if necessary, isoflurane 0.5% to 1.0% was added as a rescue anesthetic. In the intensive care unit, the remifentanil infusion was reset to 1 microg/kg/min, with midazolam administered for supplemental sedation and morphine for analgesia.

MEASUREMENTS AND MAIN RESULTS

The durations of anesthesia, surgery, and cardiopulmonary bypass were similar for the 3 study groups. In addition, dose of lorazepam premedication, time to loss of consciousness, preoperative left ventricular ejection fraction, age, weight, and sex were similar for the 3 study groups. Remifentanil alone (infusion and boluses) prevented and controlled all responses to stimulation in 44% of group 3, 37% of group 2 and 9% of group 1 patients intraoperatively. Isoflurane (0.5%-1% inspired) rescue was successful in the remaining patients in each group. Hypotension indicating discontinuation of isoflurane and reductions of remifentanil infusion rates occurred in 64% to 75% of all patients. The optimal range of remifentanil infusion was 2 to 4 microg/kg/min with isoflurane to supplement the opioid. Fifty-one patients (71%) met the criteria for extubation within 6 hours postoperatively; because of surgical practice differences, only 30 patients (59%) were actually extubated.

CONCLUSIONS

After lorazepam premedication, remifentanil infusion (2-4 microg/kg/min) supplemented intermittently with low inspired concentrations of isoflurane provided an effective anesthetic regimen for coronary artery bypass graft surgery. Early extubation times were feasible after remifentanil continuous infusions (1-5 microg/kg/min) used as the primary anesthetic component intraoperatively and for analgesia (<or=1 microg/kg/min) in the immediate postoperative setting.

A combination of intrathecal morphine and remifentanil anesthesia for fast-track cardiac anesthesia and surgery

OBJECTIVE

To determine if the combined remifentanil and intrathecal morphine (RITM) anesthetic technique facilitates early extubation in patients undergoing coronary artery bypass graft (CABG) surgery.

DESIGN

Prospective, randomized, controlled clinical trial.

SETTING

Referral center for cardiothoracic surgery at a university hospital.

PARTICIPANTS

Patients (n = 24) undergoing first-time elective CABG surgery.

INTERVENTIONS

Two groups represented RITM (n = 12) and fentanyl-based (controls, n = 12) anesthesia. Premedication was standardized to temazepam, 0.4 mg/kg, and anesthesia was induced with etomidate, 0.3 mg/kg, in both groups. The RITM group received remifentanil, 1 microg/kg bolus followed by 0.25 to 1 microg/kg/min infusion, and intrathecal morphine, 2 mg. The control group received fentanyl, 12 microg/kg in 3 divided doses. Anesthesia was maintained with isoflurane and pancuronium in both groups. After completion of surgery, the remifentanil infusion was stopped. Complete reversal of muscle relaxation was ensured with a nerve stimulator, and a propofol infusion, 0.5 to 3 mg/kg/h, was started in both groups. All patients were transferred to the intensive care unit (ICU) to receive standardized postoperative care. Intensivists and ICU nurses were blinded to the group assignment. Propofol infusion was stopped, and the tracheal extubation was accomplished when extubation criteria were fulfilled.

MEASUREMENTS AND MAIN RESULTS

Both groups were similar with respect to demographic data and surgical characteristics. Extubation times were 156 +/- 82 minutes and 258 +/- 91 minutes in the RITM and control groups (p = 0.012). Patients in the RITM group exhibited lower visual analog scale pain scores during the first 2 hours after extubation (p < 0.04). Morphine requirements during the 24 hours after extubation were 2.5 +/- 3 mg in the RITM group and 16 +/- 11 mg in the control group (p = 0.0018). Sedation scores were lower in the RITM group during the first 3 hours after extubation (p < 0.03). Pulmonary function tests as assessed by spirometry were better in the RITM group at 6 and 12 hours after extubation (p < 0.04). There were no significant differences in PaO(2) and PaCO(2) after extubation between the 2 groups. None of the patients had episodes of apnea during the immediate 24-hour postextubation period. Two patients from the RITM group required reintubation on the second and sixth postoperative days. There were no differences in ICU and hospital length of stay between the 2 groups.

CONCLUSION

Implementation of the RITM technique provided earlier tracheal extubation, decreased level of sedation, excellent analgesia, and improved spirometry in the early postoperative period. The impact of RITM on ICU and hospital length of stay and potential cost benefits require further evaluation.

Remifentanil-clonidine-propofol versus sufentanil-propofol anesthesia for coronary artery bypass surgery

OBJECTIVE

To compare a remifentanil-clonidine-propofol regimen with conventional sufentanil-propofol anesthesia.

DESIGN

Randomized, nonblinded trial.

SETTING

A single university hospital.

PARTICIPANTS

Male patients scheduled for coronary artery bypass graft (CABG) surgery.

INTERVENTIONS

In the control group, anesthesia was induced with 0.5 microg/kg of sufentanil and 0.2 to 0.3 mg/kg of etomidate after preoxygenation. Propofol (50 to 100 microg/kg/min) and sufentanil (0.5 to 1.0 microg/kg/h) were started after endotracheal intubation. Sufentanil was stopped after aortic decannulation. In the remifentanil-clonidine group, anesthesia was started with remifentanil (0.15 to 0.3 microg/kg/min), followed by etomidate (0.2 to 0.3 mg/kg). Propofol was started at 50 to 100 microg/kg/min, and after endotracheal intubation, clonidine infusion was started (6 to 20 microg/h). Patients received piritramide (0.15 mg/kg) and metamizole (20 mg/kg) for transitional analgesia. In both groups, propofol infusion was reduced to 30 to 60 microg/kg/min at skin closure and stopped when assisted spontaneous breathing led to adequate gas exchange.

MEASUREMENTS AND MAIN RESULTS

The main outcomes were recovery times; somatic variables; plasma catecholamine levels; and self-recorded pain, nausea, and vomiting. Patients in the remifentanil-clonidine group were extubated earlier and had lower plasma epinephrine and norepinephrine levels. After transitional analgesia, the remifentanil-clonidine patients had similar postoperative analgesic use and self-reported pain and side-effect scores.

CONCLUSION

Compared with a sufentanil-propofol regimen, an anesthetic regimen for CABG surgery that combines remifentanil, clonidine, and propofol provides similar hemodynamics. The remifentanil-clonidine regimen reduces catecholamine levels and hastens recovery from anesthesia.

Remifentanil, fentanyl, and cardiac surgery: a double-blinded, randomized, controlled trial of costs and outcomes

Remifentanil may be beneficial in patients undergoing coronary artery bypass graft surgery, by promoting hemodynamic stability, reducing drug requirements, and attenuating the neurohumoral "stress response." We enrolled 77 cardiac surgical patients in a double-blinded, randomized trial and randomly allocated them to one of three groups: remifentanil infusion at 0.83 micro g. kg(-1). min(-1) (Group R); fentanyl bolus, small dose, at 12 micro g/kg (Group FLD); and fentanyl bolus, moderate dose, at 24 micro g/kg (Group FMD). We found a significant difference in the median time to tracheal extubation: Group FLD, 6.5 h; Group R, 7.3 h; and Group FMD, 9.7 h (P = 0.025). Group R patients had similar times to those of Groups FLD (P = 0.14) and FMD (P = 0.30). Group FLD patients had a longer length of hospital stay (P = 0.030). Patients in Group R had a significantly infrequent rate of hypertension but a frequent rate of hypotension (P < 0.01). The urinary cortisol excretion was larger in Group FLD patients (P < 0.0005), and urine flow was smaller (P < 0.0005). Remifentanil was associated with a propofol dose reduction (P = 0.0005) and a concomitant higher bispectral index (P = 0.032). Three Group FLD patients, but none in groups FMD and R, had postoperative myocardial infarctions (P = 0.032). Remifentanil has larger drug acquisition costs but does not increase the total hospital costs associated with cardiac surgery.

IMPLICATIONS

Remifentanil did not significantly reduce the duration of tracheal intubation after cardiac surgery. Remifentanil, when compared with fentanyl (total doses of approximately 15 and 28 micro g/kg), blunts the hypertensive responses associated with cardiac surgery but is associated with more hypotension; when compared with fentanyl 15 micro g/kg, remifentanil reduces cortisol excretion. Larger-dose opioids (remifentanil 0.85 micro g. kg(-1). min(-1) or fentanyl 28 micro g/kg) were associated with a decreased rate of myocardial infarction after cardiac surgery.

The continuous recording of blood pressure in patients undergoing carotid surgery under remifentanil versus sufentanil analgesia

We compared the hemodynamic stability during carotid endarterectomy of remifentanil with that of sufentanil anesthesia. Fifty-six patients were randomly assigned into Remifentanil (n = 27) or Sufentanil (n = 29) groups. In the Remifentanil group, IV propacetamol (2 g) and morphine (0.1 mg/kg) were infused 30 min before skin closure. In the Sufentanil group, patients received 2 g propacetamol. Beat-to-beat recordings of systolic arterial blood pressure (SBP) and heart rate (HR) were stored on a computer. The maximum and minimum values of BP and HR after induction, at intubation, during the surgical procedure, and after the operation and the coefficients of variation of SBP and HR were used as indices of hemodynamic stability. The coefficients of variation of SBP and HR were similar in both groups during and after surgery. However, at intubation, maximal SBP was higher in the Sufentanil group (P < 0.05). Decreased propofol doses and isoflurane end-tidal concentrations were used in the Remifentanil group. At recovery, a similar profile of SBP and HR was found in both groups. We conclude that intra- and posthemodynamic stability was similar with remifentanil or sufentanil in patients undergoing carotid endarterectomy. However, remifentanil was more effective for blunting the increase in SBP at intubation without increasing the blood pressure-decreasing effect of induction. Intraoperative remifentanil use was associated with a decreased amount of hypnotic drug administered.

IMPLICATIONS

Beat-to-beat recordings of heart rate and blood pressure in patients undergoing carotid surgery revealed that hemodynamic stability was similar with remifentanil or sufentanil anesthesia both during and after surgery. Remifentanil was more effective in limiting the increase in blood pressure associated with intubation without increasing the blood pressure-lowering effect of induction or the blood pressure response to recovery.