Remifentanil versus meperidine for monitored anesthesia care: a comparison study in older patients undergoing ambulatory colonoscopy

The Anesthesiologist's Armamentarium: From Recreation to Medication and Back

For millennia, mankind has sought a means of altering consciousness, often aided by naturally occurring elements. Psychotropic substances have been an integral part of spiritual, medicinal, and recreational aspects of life. The origin of anesthesiology stems directly from the use of recreational drugs; early inhaled anesthetics were first used as a means of entertainment. Hence, it is no surprise that many medications in the anesthesiologist's armamentarium are diverted for recreational use. In the 172 years following the first successful public demonstration of ether anesthesia, many drugs with abuse potential have been introduced to the practice of anesthesia. Although anesthesiologists are aware of the abuse potential of these drugs, how these drugs are obtained and used for recreational purposes is worthy of discussion. There are articles describing the historical and recreational use of specific drug classes. However, to the best of our knowledge, this is the first comprehensive review focusing on the breadth of drugs used by anesthesiologists.

Colonoscopy sedation: clinical trial comparing propofol and fentanyl with or without midazolam

Colonoscopy is one of the most common procedures. Sedation and analgesia decrease anxiety and discomfort and minimize risks. Therefore, patients prefer to be sedated when undergoing examination, although the best combination of drugs has not been determined. The combination of opioids and benzodiazepines is used to relieve the patient's pain and discomfort. More recently, propofol has assumed a prominent position. This randomized prospective study is unique in medical literature that specifically compared the use of propofol and fentanyl with or without midazolam for colonoscopy sedation performed by anesthesiologists. The aim of this study was to evaluate the side effects of sedation, discharge conditions, quality of sedation, and propofol consumption during colonoscopy, with or without midazolam as preanesthetic. The study involved 140 patients who underwent colonoscopy at the University Hospital of the Federal University of Juiz de Fora. Patients were divided into two groups: Group I received intravenous midazolam as preanesthetic 5min before sedation, followed by fentanyl and propofol; Group II received intravenous anesthesia with fentanyl and propofol. Patients in Group II had a higher incidence of reaction (motor or verbal) to the colonoscope introduction, bradycardia, hypotension, and increased propofol consumption. Patient satisfaction was higher in Group I. According to the methodology used, the combination of midazolam, fentanyl, and propofol for colonoscopy sedation reduces propofol consumption and provides greater patient satisfaction.

[Colonoscopy sedation: clinical trial comparing propofol and fentanyl with or without midazolam]

Colonoscopy is one of the most common procedures. Sedation and analgesia decrease anxiety and discomfort and minimize risks. Therefore, patients prefer to be sedated when undergoing examination, although the best combination of drugs has not been determined. The combination of opioids and benzodiazepines is used to relieve the patient's pain and discomfort. More recently, propofol has assumed a prominent position. This randomized prospective study is unique in medical literature that specifically compared the use of propofol and fentanyl with or without midazolam for colonoscopy sedation performed by anesthesiologists. The aim of this study was to evaluate the side effects of sedation, discharge conditions, quality of sedation, and propofol consumption during colonoscopy, with or without midazolam as preanesthetic. The study involved 140 patients who underwent colonoscopy at the University Hospital of the Federal University of Juiz de Fora. Patients were divided into two groups: Group I received intravenous midazolam as preanesthetic five minutes before sedation, followed by fentanyl and propofol; Group II received intravenous anesthesia with fentanyl and propofol. Patients in Group II had a higher incidence of reaction (motor or verbal) to the colonoscope introduction, bradycardia, hypotension, and increased propofol consumption. Patient satisfaction was higher in Group I. According to the methodology used, the combination of midazolam, fentanyl, and propofol for colonoscopy sedation reduces propofol consumption and provides greater patient satisfaction.

Addition of low-dose ketamine to midazolam-fentanyl-propofol-based sedation for colonoscopy: a randomized, double-blind, controlled trial

STUDY OBJECTIVE

To evaluate the effects of low-dose ketamine on midazolam-fentanyl-propofol-based sedation for outpatient colonoscopy.

DESIGN

Prospective, randomized, double-blinded, placebo-controlled trial.

SETTING

Gastroenterology unit at a practice and clinical research center.

SUBJECTS

Ninety-seven healthy American Society of Anesthesiology physical status 1 volunteers.

INTERVENTIONS

Subjects were randomized to receive midazolam (0.02 mg/kg), fentanyl (1 μg/kg), and ketamine (0.3 mg/kg) and midazolam (0.02 mg/kg), fentanyl (1 μg/kg), and placebo (0.9% sodium chloride) in group K and group C, respectively. In both groups, incremental doses of propofol were used to maintain a Ramsay sedation score of 3 to 4.

MEASUREMENTS

Values of heart rate, blood pressure, oxygen saturation, and respiratory rate were measured. Procedure times, recovery times, drug doses used, complications associated with the sedation, and physician and patient satisfaction were also recorded.

MAIN RESULTS

In group K, mean amount of propofol used and mean induction time (P < .001), the need for the use of jaw thrust maneuver and mask ventilation, and the incidence of disruptive movements were significantly lower (P < .05) and gastroenterologist satisfaction at the beginning of the procedure was significantly superior (P < .05). Mean systolic blood pressures at 4, 6, 8, and 10 minutes (P < .01); diastolic blood pressures at 4, 6, and 8 minutes (P < .05); respiratory rates at 4, 6, 8, 10, 15, 20, and 25 minutes (P < .01); and oxygen saturation at 6, 8, 10, 15, and 20 minutes (P < .05) were significantly lower in group C. Patient satisfaction scores, recovery times, and discharge times were similar. No patient in either group experienced unpleasant dreams or hallucination in the postanesthesia care unit and on the first postoperative day.

CONCLUSIONS

Addition of low-dose ketamine to midazolam-fentanyl-propofol-based sedation for outpatient colonoscopy resulted in more rapid and better quality of sedation, less propofol consumption, more stable hemodynamic status, and less adverse effects with similar recovery times in adult patients.

Two dosages of remifentanil for patient-controlled analgesia vs. meperidine during colonoscopy: a prospective randomized controlled trial

BACKGROUND AND STUDY: Combined use of opiates and benzodiazepines often results in delayed discharge after colonoscopy.

AIMS

To compare sedation quality of two dosages of patient controlled analgesia remifentanil with one another and with that of a midazolam-meperidine association during colonoscopy.

METHODS

Ninety patients undergoing colonoscopy were randomly assigned to three groups. Group M received a meperidine bolus (0.7 mg/kg) and sham patient controlled analgesia. Group R1 received remifentanil 0.5 μg/kg and group R2 remifentanil 0.8 μg/kg together with a patient-controlled analgesia pump injecting further boluses (2-min lock-out). Technical difficulties of the examination, gastroenterologist's and patient's satisfaction with sedoanalgesia were evaluated after colonoscopy on a 100 mm Visual Analogue Scale. Patient's satisfaction was assessed 24 h later.

RESULTS

Group M had more adverse events (p = 0.044), required more rescue boluses (p = 0.0010), had lower Observer's Assessment of Alertness and Sedation Scale score at the end of the procedure (p = 0.0016) and longer discharge time (p = 0.0001). Groups R1 and R2 did not differ with respect to these variables. Patient's degree of pain and satisfaction with sedo-analgesia, endoscopist's technical difficulty and satisfaction were not different among groups.

CONCLUSIONS

Remifentanil patient controlled analgesia is a safe approach to sedation for colonoscopy.

Analgesia without sedatives during colonoscopies: worth considering?

Colonoscopy is a proven method for bowel cancer screening and is often experienced as a painful procedure. Today, there are two main strategies to facilitate colonoscopy. First, deep sedation results in satisfied patients but increases sedation-associated risks and raises costs for healthcare providers. Second, there is the advocacy for colonoscopies without any form of sedation. This might be an option for a special group of patients, but does not hold true for everybody. Following Moerman’s hypothesis: “If pain is the crucial point, why do we need sedation?” this review shows the analgesic options for a painless procedure, increasing success rates without increasing risk of sedation. There are two agents, with the potential to be a nearly ideal analgesic agent for colonoscopy: alfentanil and nitrous oxide (N₂O). Administration of either substance causes the patient to be comfortable yet alert and facilitates a short turnover. Advantages of these drugs include rapid onset and offset of action, analgesic and anxiolytic effects, ease of titration to desired level, rapid recovery, and an excellent safety profile.

Sedation and analgesia in gastrointestinal endoscopy: What’s new?

Various types of sedation and analgesia technique have been used during gastrointestinal endoscopy procedures. The best methods for analgesia and sedation during gastrointestinal endoscopy are still debated. Providing an adequate regimen of sedation/analgesia might be considered an art, influencing several aspects of endoscopic procedures: the quality of the examination, the patient’s cooperation and the patient’s and physician’s satisfaction with the sedation. The properties of a model sedative agent for endoscopy would include rapid onset and offset of action, analgesic and anxiolytic effects, ease of titration to desired level of sedation, rapid recovery and an excellent safety profile. Therefore there is an impulse for development of new approaches to endoscopic sedation. This article provides an update on the methods of sedation today available and future directions in endoscopic sedation.

Remifentanil vs. meperidine for patient-controlled analgesia during colonoscopy: a randomized double-blind trial

OBJECTIVES

The aim was to compare patients' and endoscopists' satisfaction in terms of efficacy and safety of remifentanil patient-controlled analgesia (PCA) during colonoscopy with that of a combination of midazolam and meperidine.

METHODS

Sixty patients undergoing colonoscopy were randomly assigned to two groups. All of the patients received midazolam 0.03 mg/kg intravenously for premedication. In the remifentanil group, a bolus dose of remifentanil was given, and a patient-controlled sedation analgesia (PCSA) pump was set to inject further bolus doses with no "lockout" time. Patients in the meperidine group received a bolus of meperidine and sham PCSA. Non-invasive arterial blood pressure, electrocardiography, and pulse oximetry were monitored throughout the study. The Observer's Assessment of Alertness and Sedation Scale (OAA/S) was performed at baseline, every 5 min during, and after colonoscopy. Assessment of pain and satisfaction with sedoanalgesia was scheduled after colonoscopy and 24-72 h later by a 100 mm visual analog scale (VAS). The technical difficulty of the examination and the gastroenterologist's satisfaction were assessed similarly.

RESULTS

The degree of pain, the level of satisfaction with sedoanalgesia by patients and gastroenterologists, and the degree of difficulty experienced by the endoscopist were not different in the two groups. The time to reach an Aldrete score > or = 9 was significantly shorter in the remifentanil group (P < 0.0001); discharge times did not differ between the groups (P = 0.36). There was no difference between the groups regarding the duration of colonoscopy (P = 0.82) and the stability of vital signs. At the end of the procedure, OAA/S was significantly higher in the remifentanil group (P = 0.03).

CONCLUSIONS

Remifentanil PCA is safe and effective to induce sedoanalgesia during colonoscopy. Further studies should address the optimization of dosing and lock out setting.

Remifentanil compared with midazolam and pethidine sedation during colonoscopy: a prospective, randomized study

PURPOSE

The objective of our study was to compare the safety and efficacy of remifentanil during colonoscopy with those of the standard combination of midazolam and pethidine.

METHODS

One-hundred and sixteen consecutive patients scheduled for colonoscopy were randomly assigned to groups A or B. Patients in group A (n = 56) received intravenous (IV) midazolam and pethidine. Patients in group B (n = 60) received IV remifentanil.

RESULTS

Recovery was faster in group B (0 min) than in group A (56 +/- 11.3 min) (P < 0.001). There was a marked difference between groups B and A with regard to the time of hospital discharge-28.7 +/- 4.3 and 148.9 +/- 34 min, respectively (P < 0.001). Patients in group A rated the procedure as comfortable, as also did those in group B. A combination of midazolam and pethidine had a greater affect on patients' cardiorespiratory characteristics.

CONCLUSION

Remifentanil during colonoscopy provides sufficient pain relief with better hemodynamic stability, less respiratory depression, and significantly faster recovery and hospital discharge than moderate sedation with midazolam and pethidine.

Self-reports of anxiety in burn-injured hospitalized adults during routine wound care

The purpose of this investigation was to examine the amount of anxiety patients believed tolerable and the amount of anxiety experienced during routine burn wound care. Participants included 47 hospitalized adults who provided data for four consecutive assessment periods. Patients (mean TBSA, 16%; range, 2-70%) were primarily Caucasian (87%) and had an average hospital stays of 23 days (range, 11-130). Reports of what level of anxiety they would be able to tolerate and what level of anxiety had been experienced were assessed using 10-point Graphic Rating Scales. The use of anxiolytic was recorded, and patient suggestions for reducing anxiety were obtained. The single most commonly endorsed anxiety treatment goal was 0, although 53% consistently chose a treatment goal other than 0 (range, 1-6). Two repeated-measure analyses of variance indicated that the amount of anxiety patients could tolerate and the amount they reported experiencing did not change over the course of time. Paired t-tests revealed that patients routinely reported more anxiety than they considered tolerable. Analyses of anxiety reports of patients treated with anxiolytics (n = 6) vs patients receiving no anxiolytics (n = 41) revealed inconsistent differences in actual anxiety and treatment goals across time. In general, patient suggestions for lessening anxiety included requests for education, communication, additional medications, and manipulation of the hospital environment. Anxiety for burn-injured, hospitalized adults remains a concern. Our findings are consistent with the literature indicating that adult patients hospitalized for burn wound care report appreciable anxiety, over and above what they consider "tolerable." Continued research is needed and should include investigations into the relationship between pain and anxiety during routine wound care.

Opioid Analgesia for Hysterosalpingography: Controlled Double-Blind Prospective Trial with Remifentanil and Placebo

BACKGROUND/AIMS

A hysterosalpingogram is an integral part of the evaluation of infertility, however, it is often painful.

METHODS

We conducted a randomized double-blinded, placebo-controlled trial of intravenous infusion of remifentanil in women undergoing hysterosalpingography (HSG). We randomly allocated 62 patients scheduled for HSG to receive either a continuous infusion of 0.25 microg.kg(-1) of remifentanil or placebo. The degree of pain was documented via 10-cm visual analog scales (VAS). Patients' discomfort, side effects and recovery times were also recorded.

RESULTS

The VAS scores during HSG were 1.25 +/- 1.31 in the remifentanil group and 4.78 +/- 1.7 in the placebo group (p < 0.001). There were more patients in the remifentanil group that rated their condition as excellent (p < 0.001). The groups did not differ with regard to the incidence of side effects. The recovery times were found statistically longer in the remifentanil group (14 +/- 5 vs. 10 +/- 3 min). All the patients were discharged 30 min after the procedures without any side effects.

CONCLUSION

Remifentanil infusion during HSG is superior to placebo for relief of pain with minimal opioid side effects.

Can remifentanil be a better choice than propofol for colonoscopy during monitored anesthesia care?

BACKGROUND AND OBJECTIVE

This prospective, randomized trial was designed to test the hypothesis that continuous infusion of low-dose remifentanil can provide effective analgesia, sedation, amnesia, patient comfort and stable recovery profile without respiratory depression when compared with propofol infusion during colonoscopy.

METHODS

One hundred patients were randomly assigned to receive either remifentanil (group R, 0.5 microg/kg followed by 0.05 microg/kg/min, n = 50) or propofol (group P, 0.5 mg/kg followed by 50 microg/kg/min, n = 50). Supplemental doses of remifentanil 12.5 microg in group R and propofol 10 mg in group P were given to treat complaints of moderate to severe pain and discomfort. Hemodynamic and respiratory data, pain, discomfort and sedation scores, patient and gastroenterologist satisfaction and recovery profiles were recorded.

RESULTS

The duration of colonoscopy was longer in group P. The mean arterial pressure, heart rate and end-tidal CO2 remained stable during the procedure and were comparable between the groups. After bolus injection of the study drugs, the respiratory rate and oxygen saturation values were lower in group R than in group P. Only one patient in group R required airway support. Pain and discomfort scores were better in group R than in group P. Sedation levels were higher in group P than in group R. Group P needed more supplemental doses than group R. The time to reach an Aldrete score of nine or more was shorter in group R, but discharge times were similar in the two groups. Amnesia was better in group P. Nausea and vomiting were more frequent in group R during the recovery phase.

CONCLUSION

Low-dose remifentanil infusion with intermittent bolus injections can provide adequate sedation, amnesia and better analgesia than propofol infusion during colonoscopy. However, remifentanil-induced nausea and vomiting may be a problem during the recovery phase.

Comparison of remifentanil with fentanyl for deep sedation in oral surgery

PURPOSE

The aim of this study was to compare recovery for oral surgery patients given a deep sedation regimen of midazolam, propofol, and remifentanil with a standard control of fentanyl in place of remifentanil.

MATERIALS AND METHODS

This investigation was designed as a randomized, prospective, single-blinded controlled study. Group 1, the control, received midazolam 0.03 mg/kg, fentanyl 1 microg/kg, and propofol initially at 140 microg/kg/min. Group 2 received midazolam 0.03 mg/kg, remifentanil: propofol (1:500) given at an initial propofol infusion rate of 40 microg/kg/min. Outcome measures included time to response to verbal command, Aldrete score = 9, Postanesthesia Discharge Scoring System = 7, and assessment by the Digit Symbol Substitution Test.

RESULTS

Forty-seven subjects were entered in the study. Baseline findings were homogenous between the 2 groups. Subjects in group 2 recovered earlier (P < .005) and required less propofol for both the induction (0.8 +/- 0.4 versus 1.2 +/- 0.6 mg/kg; mean +/- SD, P < .01) and maintenance of deep sedation (46 +/- 9 versus 131 +/- 17 microg/kg/min; P < .005). There were minor differences in vital signs.

CONCLUSIONS

This study demonstrated that this remifentanil regimen provided significantly more rapid recovery and used significantly less propofol compared with the fentanyl regimen.

Remifentanil used to supplement propofol does not improve quality of sedation during spontaneous respiration

STUDY OBJECTIVE

To evaluate whether the use of remifentanil to supplement propofol during spontaneous respiration confers any benefits in terms of quality of sedation and recovery, or in terms of reduction in propofol requirements.

DESIGN

Prospective, randomized, double-blind study.

SETTING

University hospital.

PATIENTS

50 ambulatory adult ASA physical status I and II patients scheduled for total colonoscopy.

INTERVENTIONS

Patients were randomized to receive either propofol alone or propofol plus remifentanil 0.1 microg/kg/min, while independently maintaining spontaneous respiration.

MEASUREMENTS

Cardiovascular and respiratory variables were measured before induction and at 1-minute intervals thereafter. Recovery from anesthesia was assessed using simple verbal commands and the Steward Post Recovery Score. Patient satisfaction was measured with a visual analog scale. Computer simulation was used to calculate the effect-site concentrations of propofol and remifentanil.

MAIN RESULTS

The depressant effects on blood pressure and respiratory function were significantly higher when propofol and remifentanil were combined. Although the addition of remifentanil resulted in a decrease of propofol usage, recovery of anesthesia was faster and patient satisfaction was higher when using propofol alone.

CONCLUSIONS

The addition of remifentanil to propofol during spontaneous ventilation offered no benefits compared with the use of propofol alone.

[Remifentanil is an effective alternative to propofol for patient-controlled analgesia during digestive endoscopic procedures]

PURPOSE

Unlike propofol, the self-administration of remifentanil for sedation in gastrointestinal endoscopies has never been evaluated formally. We wanted to compare the efficacy and tolerance of patient self-administration of remifentanil vs propofol during gastrointestinal endoscopy.

METHOD

This prospective randomized, single-blinded study, included 77 patients undergoing gastrointestinal endoscopy. Patients were divided into two groups: group R received remifentanil (5 microg.kg(-1).hr(-1) infusion, 25 microg boli, refractory period of five minutes) and group P received propofol (2 mg.kg(-1).hr(-1) infusion, 0.5 mg.kg(-1) boli, refractory period of ten minutes). A 1 mg.kg(-1) bolus of propofol was administered before the procedure began in cases of marked anxiety. Additional boli of 25 microg of remifentanil or 0.5 mg.kg(-1) of propofol were administered when patients complained during the refractory period. The evaluation targeted analgesic efficacy during the procedure and patient satisfaction. The degree of sedation during the procedure and the occurrence of adverse reactions were analyzed.

RESULTS

Patient satisfaction was high and comparable in both groups, with the number of awake and oriented patients being significantly higher in group R. Hemodynamic and respiratory tolerance was comparable in both groups, despite two episodes of desaturation in group R. The incidence of nausea was significantly higher in group R.

CONCLUSIONS

The self-administration of remifentanil for sedation during gastrointestinal endoscopies is as effective as the self-administration of propofol and can be offered to patients, especially when it is desirable that they remain conscious during the procedure.

Propofol versus remifentanil for monitored anaesthesia care during colonoscopy

BACKGROUND AND OBJECTIVE

We conducted an open, prospective, randomized study to compare the efficacy, safety and recovery characteristics of remifentanil or propofol during monitored anaesthesia care in patients undergoing colonoscopy.

METHODS

Forty patients were randomly assigned to receive either propofol (1 mg kg(-1) followed by 10 mg kg (-1) h(-1), n = 20) or remifentanil (0.5 microg kg(-1) followed by 0.2 microg kg(-1) min(-1), n = 20). The infusion rate was subsequently adapted to clinical needs.

RESULTS

In the propofol group, arterial pressure and heart rate decreased significantly from the baseline. These variables remained unchanged in the remifentanil group, but hypoventilation occurred in 55% of patients. Early recovery was delayed in the propofol group (P < 0.002). Recovery of cognitive and psychomotor functions was faster in the remifentanil group. Fifteen minutes after anaesthesia, the Digit Symbol Substitution Test score was 28.6 +/- 12.8 versus 36.2 +/- 9.4 and the Trieger Dot Test score was 25.6 +/- 8.1 versus 18.7 +/- 4.1 in the propofol and remifentanil groups, respectively (both P < 0.05). Patient satisfaction, using a visual analogue scale, was higher in the propofol group (96 +/- 7 versus 77 +/- 21, P < 0.001).

CONCLUSIONS

Remifentanil proved efficient in reducing pain during colonoscopy. Emergence times were shorter and the recovery of cognitive function was faster with remifentanil compared with propofol. Remifentanil provided a smoother haemodynamic profile than propofol; however, the frequent occurrence of remifentanil-induced hypoventilation requires the cautious administration of this agent.

Conscious analgesia/sedation with remifentanil and propofol versus total intravenous anesthesia with fentanyl, midazolam, and propofol for outpatient colonoscopy

BACKGROUND

This study tested the hypothesis that, for colonoscopy, analgesia/sedation with remifentanil and propofol might be more effective compared with anesthesia by intravenous administration of midazolam, fentanyl, and propofol.

METHODS

In a prospective, randomized trial, 100 adult patients received either conscious analgesia/sedation (Sedation group) or total intravenous anesthesia (TIVA group). Analgesia/sedation was achieved by infusion of remifentanil (0.20 to 0.25 microg/kg/min) and propofol in titrated doses. TIVA was induced by intravenous administration of fentanyl (2 microg/kg), midazolam (0.05 mg/kg) and propofol (dosage titrated). Cardiorespiratory parameters and bispectral index were monitored and recorded. The quality of the analgesia was assessed with a Numerical Pain Rating Scale (NRS); recovery level and return of psychomotor efficiency were evaluated with, respectively, the Aldrete scale and a Modified Post Anesthesia Discharge Scoring (MPADS) system.

RESULTS

Both groups of 50 patients were comparable with respect to demographic data, initial parameters, and duration of colonoscopy. All patients in the TIVA group found the colonoscopy painless (NRS score 0). In the Sedation group, the average pain intensity score was 0.4 (0.8). There was a marked difference between the Sedation and TIVA groups with respect to the time from the end of the procedure until the maximum MPADS score was reached: respectively, -6.9 (4.0) versus 25.7 (8.4) minutes (p < 0.001). In the TIVA group, changes in mean arterial pressure and heart rate and signs of respiratory depression were significant (p < 0.05).

CONCLUSIONS

Combined administration of remifentanil and propofol for colonoscopy provides sufficient analgesia, satisfactory hemodynamic stability, minor respiratory depression, and rapid recovery, and allows patients to be discharged approximately 15 minutes after the procedure.