Significance of patient-controlled sedation during colonoscopy - Results from a prospective randomized controlled study

Background - In France, general anesthesia is given to more than 90% of patients undergoing colonoscopy although in several countries sedation is limited to intolerant patients. This study was carried out to determine whether Patient-Controlled Sedation (PCS) could provide a lighter sedation than general anesthesia adapted to the patient's individual requirement. Methods - Patients aged from 18 to 80 scheduled for elective colonoscopy were prospectively randomized to receive either standard sedation (control group) or patient-controlled-sedation (PCS). In the control group, patients received a continuous infusion of propofol. Patients in the PCS group were connected to an infusion pump containing propofol and self-administered 20-mg boluses as often as they required. An anesthetist was present throughout the procedure. Patient satisfaction measured on a visual analog scale four hours after colonoscopy was the main outcome criterion. Results - From December 2002 to September 2003, 402 patients underwent elective colonoscopy, 173 of them were eligible and were asked to participate in the study. Seventy-two gave their informed consent and were prospectively randomized. The patients' mean satisfaction scores were not statistically different between the two groups: 84.7 mm (PCS group) vs. 91.5 mm (control group); P = 0.24. Mean doses of propofol (60 mg vs. 248 mg; P < 0.001), depth of sedation and time before discharge (1.75 hours vs. 4.45 hours) were significantly lower for patients in the PCS group; nine of them (25.7%) did not use the pump and had total colonoscopy without sedation. There were no statistically significant differences between the two groups regarding total duration of colonoscopy (19.4 min (PCS) vs. 18 min (control)) difficulty and therapeutic procedures (biopsy or polypectomy). Two weeks after the procedure, 96.5% of patients in the PCS group were willing to repeat the examination under the same conditions vs. 72.5% of patients in the control group (P = 0.03). Conclusions - Our results demonstrate that need of sedation is widely overestimated in France. A subset of our patients is willing to consider colonoscopy without general anesthesia. For them, PCS with propofol is an effective and very well accepted form of sedation.