Randomized trial of standard versus magnetic endoscope imaging colonoscopes for unsedated colonoscopy

Veterans Affairs Medical Center, University of California San Francisco, San Francisco, California, USA.
Gastrointestinal endoscopy (Impact Factor: 5.37). 02/2012; 75(5):1031-1036.e1. DOI: 10.1016/j.gie.2011.12.030
Source: PubMed


Unsedated colonoscopy has potential benefits, including decreased costs and decreased risks.
To determine whether patient comfort during unsedated colonoscopy can be improved through the use of a magnetic endoscopic imaging (MEI) colonoscope compared with a standard colonoscope.
Prospective, patient-blinded, randomized, controlled trial.
San Francisco Veterans Affairs Medical Center.
Veterans undergoing outpatient screening or surveillance colonoscopy.
Use of a standard or MEI colonoscope during unsedated colonoscopy.
The primary outcome variable was patient perception of pain using a 7-point scale. The secondary endpoint was patient willingness to undergo a future unsedated colonoscopy.
Of the 160 patients enrolled, 140 completed an unsedated colonoscopy in the study protocol. In a per-protocol analysis, the mean and median pain score was 3.12 (standard deviation 1.22) and 4 (interquartile range 2-4) for the standard colonoscope group and 3.06 (standard deviation 1.13) and 3 (interquartile range 2-4) for the MEI group, where 3 was mild pain (P = not significant). Overall, 80% of subjects were willing to undergo a future unsedated colonoscopy for screening or surveillance. In an intention-to-treat analysis, 80% of subjects (64/80) in the standard colonoscope arm and 79% in the MEI arm (63/80) were willing to undergo a future unsedated colonoscopy (P = not significant).
Single-center study of mostly male veterans.
This patient-blinded, randomized, controlled trial did not demonstrate any difference in patient perception of pain or willingness to undergo unsedated examinations when using the MEI versus the conventional colonoscope. Unsedated colonoscopy is generally feasible and well tolerated and is associated with high patient satisfaction rates.

12 Reads

  • No preview · Article · May 2012 · Gastrointestinal endoscopy
  • [Show abstract] [Hide abstract]
    ABSTRACT: The explanation why water exchange colonoscopy produces a significant reduction of pain during colonoscopy is unknown. A recent editorial recommended use of magnetic endoscope imaging (MEI) to elucidate the explanation. In unselected patients to show that MEI documents less frequent loop formation when water exchange is used. Observational, performance improvement. Veterans Affairs outpatient endoscopy. Routine colonoscopy cases. Colonoscopy using air or water exchange method was performed as previously described. The MEI equipment (ScopeGuide, Olympus) with built-in magnetic sensors displays the configuration of the colonoscope inside the patient. During sedated colonoscopy the endoscopist was blinded to the ScopeGuide images which were recorded and subsequently reviewed. Loop formation based on a visual guide provided by Olympus. There were 41 and 32 cases in the water exchange and air group, respectively. The sigmoid N loop was most common, followed by the sigmoid alpha loop, and exaggeration of scope curvature at the splenic flexure/transverse colon. Of these, 20/32 vs. 9/41 patients (p=0.0007) had sigmoid looping, and 17/32 vs. 9/41 patients (p=0.0007) had sigmoid/splenic looping when the scope tip was in the transverse colon, in the air and water exchange group, respectively. Colonoscopy method was not blinded and non randomized. MEI data objectively demonstrated significantly fewer loops during water exchange colonoscopy, elucidating its mechanism of pain alleviation - attenuation of loop formation. Since MEI feedback enhances cecal intubation by trainees, the role of MEI combined water exchange in speeding up trainee learning curves deserves further evaluations.
    No preview · Article · Jul 2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: CO(2) is rapidly absorbed from the colon and eliminated via the lung. Insufflation of CO(2) instead of air during colonoscopy can reduce distention-induced pain. This study aimed to evaluate the effects of CO(2) insufflation on pain during intubation and extubation and to identify predictors of pain and discomfort during colonoscope insertion. Prospective, randomized, controlled trial. Single tertiary medical center in Taiwan. A total of 193 patients enrolled from September 2010 through June 2011. Colonoscope insertion with either air or CO(2) insufflation. CO(2) was used for extubation in both groups. The main outcome measurement was pain, recorded on a 10-point visual analog scale (VAS) for left-sided colonoscope insertion and right-sided colonoscope insertion and at 1, 3, 6, and 24 hours post-procedure. Colonoscope cecal intubation time and extubation time, completeness of intubation, and loop formation were also assessed. CO(2) insufflation during colonoscope intubation was used in 98 patients and air in 97 patients. The mean pain scores during intubation were low (2-3) for patients undergoing air insufflation and were not reduced further in patients receiving CO(2). A mean pain score of 0 was reported by both groups for all postprocedure time points. Multivariate analysis identified sex, loop formation of the sigmoid colon, time to reach the transverse colon, and requested sedation as factors that significantly affect VAS pain scores. This study was limited in scope to a single medical center with experienced endoscopists. We detected no significant benefit to the use of CO(2) insufflation compared with air insufflation during intubation for colonoscopy performed by experienced colonoscopists. The absence of postprocedure pain in both groups supports previous observations that CO(2) insufflation during extubation is effective in reducing postprocedure pain. Female sex and loop formation were identified as key factors influencing pain scores on colonoscope insertion. (Clinical trial registration number: TSGHIRB-099-05-081.).
    No preview · Article · Jan 2013 · Gastrointestinal endoscopy
Show more