Patient-controlled sedation and analgesia, using propofol and alfentanil, during colonoscopy: a prospective randomized controlled trial.

Objective: Patient-controlled sedation (PCS) enables titration of dosage to an individual's requirements and is potentially useful in colonoscopy. The aim was to compare the value of patient-controlled sedation, using propofol and alfentanil, with that of intravenous diazemuls and pethidine during colonoscopy.

Methods: Following randomization, 66 patients undergoing colonoscopy received either an intravenous bolus of pethidine (50 mg) and diazemuls (10-20 mg) prior to colonoscopy or were connected to an infusion pump containing propofol (10 mg/ml) and alfentanil (25 microg/ml). Patients self-administered 0.5 ml boluses as often as they required. Pain and sedation score were recorded by a nurse specialist and on a patient questionnaire. An anaesthetist was present throughout the procedure.

Results: PCS provided lighter sedation (median sedation score, 3 versus 4; P=0.0001), less analgesia (median pain score, 1 versus 0; P=0.004), a smaller maximum fall in systolic blood pressure (23 mmHg versus 33 mmHg; P=0.02) and a faster recovery time (median 10 min versus 40 min; P=0.0001), irrespective of the dose administered, compared with a diazemuls-pethidine combination. The duration of the procedure was unaffected. All patients were satisfied with their level of sedation.

Conclusions: Patient-controlled sedation is an effective alternative to premedication with narcotic/benzodiazepine combinations during colonoscopy.