Anesthesia and sedation in the endoscopy suite? (influences and options)

Randomized comparison of recovery time after use of remifentanil alone versus midazolam and meperidine for colonoscopy anesthesia

BACKGROUND AND AIM

Although the combination of midazolam-meperidine has been widely used as a sedation regimen for colonoscopy, its residual effect which is longer than the duration of a colonoscopy procedure can delay patient recovery and discharge. Remifentanil, an ultra-short-acting opioid, has a very brief duration of action. We hypothesized that using remifentanil alone for colonoscopy would provide shorter recovery time compared with the midazolam-meperidine combination.

METHODS

Time to achieve Aldrete score = 10 was determined and compared in patients who were randomly allocated to receive remifentanil alone (group-R, n = 27) or a midazolam-meperidine combination (group-MM, n = 27) for colonoscopy. Intergroup differences in sedation, recall analgesia, cardio-respiratory profiles, and satisfaction of patient and endoscopist were also determined during and after colonoscopy.

RESULTS

Group-R showed a significantly shorter recovery time than group-MM (median [25-75%], 0 [0-10] vs 30 [15-30] min, P < 0.001). Group-R showed significantly higher bispectral-index values during colonoscopy (92 [85-96] vs 84 [80-87], P = 0.001); a higher incidence of recall of explanations given during and after colonoscopy (100 vs 48% and 96 vs 52%, both P < 0.001); and a lower distress score (visual analog scale 30/100 vs 37/100 mm, P = 0.002), than did group-MM. Neither extent of pain, incidence of hemodynamic instability nor incidence of respiratory depression differed between the groups.

CONCLUSIONS

Remifentanil for colonoscopy afforded faster recovery compared to midazolam-meperidine combination. It also provided greater patient-endoscopist communication and satisfaction with comparable patient analgesia and cardiorespiratory profile during colonoscopy.

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.

Ketamine, propofol and low dose remifentanil versus propofol and remifentanil for ERCP outside the operating room: is ketamine not only a "rescue drug"?

BACKGROUND

Endoscopic retrograde cholangiopancreatography ERCP is a painful and long procedure requiring transient deep analgesia and conscious sedation. An ideal anaesthetic that guarantees a rapid and smooth induction, good quality of maintenance, lack of adverse effects and rapid recovery is still lacking. This study aimed to compare safety and efficacy of a continuous infusion of low dose remifentanil plus ketamine combined with propofol in comparison to the standard regimen dose of remifentanil plus propofol continuous infusion during ERCP.

MATERIAL/METHODS

322 ASAI-III patients, 18-85 years old and scheduled for planned ERCP were randomized. Exclusion criteria were a predictable difficult airway, drug allergy, and ASA IV-V patients. We evaluated Propofol 1 mg/kg/h plus Remifentanil 0.25 µg/kg/min (GR) vs. Propofol 1 mg/kg/h plus Ketamine 5 µg/kg/min and Remifentanil 0.1 µg/kg/min (GK). Main outcome measures were respiratory depression, nausea/vomiting, quality of intraoperative conditions, and discharge time. P≤0.05 was statistically significant (95% CI).

RESULTS

Respiratory depression was observed in 25 patients in the GR group compared to 9 patients in the GK group (p=0.0035). ERCP was interrupted in 9 cases of GR vs. no cases in GK; patients ventilated without any complication. Mean discharge time was 20±5 min in GK and 35±6 min in GR (p=0.0078) and transfer to the ward delayed because of nausea and vomiting in 30 patients in GR vs. 5 patients in GK (p=0.0024). Quality of intraoperative conditions was rated highly satisfactory in 92% of GK vs. 67% of GR (p=0.028).

CONCLUSIONS

The drug combination used in GK confers clinical advantages because it avoids deep sedation, maintains adequate analgesia with conscious sedation, and achieves lower incidence of postprocedural nausea and vomiting with shorter discharge times.

General anesthesia and altered states of arousal: a systems neuroscience analysis

Placing a patient in a state of general anesthesia is crucial for safely and humanely performing most surgical and many nonsurgical procedures. How anesthetic drugs create the state of general anesthesia is considered a major mystery of modern medicine. Unconsciousness, induced by altered arousal and/or cognition, is perhaps the most fascinating behavioral state of general anesthesia. We perform a systems neuroscience analysis of the altered arousal states induced by five classes of intravenous anesthetics by relating their behavioral and physiological features to the molecular targets and neural circuits at which these drugs are purported to act. The altered states of arousal are sedation-unconsciousness, sedation-analgesia, dissociative anesthesia, pharmacologic non-REM sleep, and neuroleptic anesthesia. Each altered arousal state results from the anesthetic drugs acting at multiple targets in the central nervous system. Our analysis shows that general anesthesia is less mysterious than currently believed.

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.

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.

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.

Total intravenous versus inhalational anaesthesia for colonoscopy: a prospective study of clinical recovery and psychomotor function

A randomized, prospective study was conducted on 69 patients comparing recovery after two different anaesthetic techniques for ambulatory colonoscopy. Thirty-five patients received an intravenous fentanyl (1 microg/kg), midazolam (0.05 to 0. 075 mg/kg) and propofol (10 to 20 mg boluses as required) combination. 34 patients received sevoflurane in 67% nitrous oxide. Drug administration was titrated to clinical signs. At baseline and 30, 60, 90 and 120 minutes after the procedure patient performance on a comprehensive battery of psychomotor tests was recorded. Emergence times were noted. Depth of sedation was assessed at 5 minute intervals for 30 minutes after the end of the procedure. Emergence times were faster in the fentanyl/midazolam/propofol group by 2.2 minutes. A lower sedation score was detected at 20 minutes in the sevoflurane/nitrous oxide group. Psychomotor impairment was of a greater magnitude and more prolonged by 30 to 90 minutes in the fentanyl/midazolam/propofol group. It is concluded that a sevoflurane/nitrous oxide anaesthetic has a suitable recovery profile for ambulatory colonoscopy and results in faster recovery of cognitive function compared with a fentanyl, midazolam and propofol combination.