Use of a variable-stiffness colonoscope decreases the dose of patient-controlled sedation during colonoscopy: a randomized comparison of 3 colonoscopes.

Background: The variable-stiffness colonoscope incorporates different degrees of stiffness of the insertion tube, which can be adjusted during the examination. Whether its use can lead to reduced procedure-related pain and sedative use is unknown.
Objective: Our purpose was to compare the use of 3 types of colonoscope with different shaft stiffnesses in relation to procedure-related pain and sedative consumption.
Design: Prospective randomized trial.
Setting: Endoscopy unit of a university-affiliated hospital.
Patients: Consecutive patients undergoing ambulatory colonoscopy.
Interventions: Random assignment was made of patients into 3 groups to receive colonoscopic examinations by one of the 3 types of colonoscope: conventional standard adult size, 1.3-m; 1.6-m; and the new variable-stiffness adult size, full-length (1.6-m) colonoscope. A mixture of propofol and afentanil, delivered by a patient-controlled syringe pump, was used for sedation in all groups.
Main Outcome Measures: Outcome measures included dose of patient-controlled sedation consumed, pain score, cecal intubation rate, cecal intubation time, requirement of abdominal pressure and change of patients' positions during colonoscopy, and endoscopists and patients' satisfaction scores according to a visual analog scale.
Results: A total of 335 patients were randomized. Patients in group 3 used significantly less propofol (in milligrams per kilograms, mean [SD]) compared with the other 2 groups (group 1: 1.00 [0.75], group 2: 0.93 [0.62], and group 3: 0.75 [0.65]; P = .02; 1-way analysis of variance). The mean (SD) pain score was also lower in group 3.
Limitations: The endoscopists were not blinded.
Conclusion: The use of the new variable-stiffness adult-size colonoscope significantly reduced procedure-related pain and doses of sedative medications during colonoscopy.