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 μg kg−1 followed by 0.2 μg 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.