The safety, feasibility, and acceptability of patient-controlled sedation for colonoscopy: prospective study.

OBJECTIVE To assess the safety, feasibility, and acceptability of patient-controlled sedation for elective day-case colonoscopy, and the factors predicting patients' unwillingness to use patient-controlled sedation for colonoscopy. DESIGN Prospective, non-randomised study. SETTING University-affiliated endoscopy centre, Hong Kong. PARTICIPANTS Five hundred patients who underwent elective day-case colonoscopy were prospectively recruited from January 2001 to June 2002. INTERVENTION Sedation for colonoscopy was a mixture of propofol and alfentanil, which was delivered by means of a patient-controlled syringe pump. Each bolus delivered 4.8 mg propofol and 12 microg alfentanil. No loading dose was used and the lockout time was set at zero. MAIN OUTCOME MEASURES Cardiopulmonary complications, dose of patient-controlled sedation used, recovery time, satisfaction score, delayed side-effects, and the willingness to use the same sedation protocol for future colonoscopy. A multiple stepwise logistic regression model was used to assess which factors might predict unwillingness to use patient-controlled sedation for colonoscopy. RESULTS The mean (standard deviation) age of patients was 53.0 (13.9) years. The mean dose of propofol consumed was 0.93 (0.69) mg/kg. Forty-three (8.6%) patients developed hypotension during the procedure. The mean satisfaction score was 7.2 (2.6). Sixteen (3.2%) patients developed delayed side-effects. The median (interquartile range) recovery time was 0 (0-5) minutes. Approximately 78% of patients were willing to use patient-controlled sedation for future colonoscopy if needed. Younger age (<50 years), female sex, a higher mean dose of sedatives used, a lower satisfaction score, and the presence of delayed side-effects were independent factors that were associated with patients' unwillingness to use patient-controlled sedation for colonoscopy. CONCLUSION . The use of patient-controlled sedation for elective colonoscopy is safe, feasible, and acceptable to most patients.