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

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.

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.

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.

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.