Background: Pain during colonoscopy is primarily related to mesenteric stretching from looping of the colonoscope insertion tube. Prompt recognition and removal of loops reduces patient discomfort and may lessen sedation requirements. Magnetic endoscope imaging allows real-time visualization of the colonoscope during insertion. The effect of magnetic endoscope imaging on patient pain and sedation requirements was assessed in a prospective randomized controlled trial.
Methods: A total of 122 consecutive patients undergoing routine colonoscopy by a single experienced endoscopist were randomized to have the procedure performed either with the endoscopist viewing the imager display (n = 62), or without the imager view (n = 60). Procedures began with administration of hyoscine-N-butylbromide alone, and sedative medications (midazolam and meperidine) were self-administered by the patient with a patient-controlled analgesia pump. Cardiorespiratory parameters were recorded and patient pain was assessed with a 100-mm visual analogue scale.
Results: The number of attempts at straightening the colonoscope was fewer (median 8 [0-66] vs. 15 [0-87], p = 0.0076) and the duration of looping less (median 4.5 min [0-27.3 min] vs. 6.4 min [0-29.4 min]), when the endoscopist was able to see the imager view. The total number of patient demands (by patient-controlled analgesia) for medication (median 1 vs. 2.5) and total doses of midazolam (median 0.44 mg vs. 0.88 mg) and meperidine (median 16.75 mg vs. 32.5 mg) administered did not significantly differ between patients examined with or without the imager. Patient pain scores were also similar.
Conclusions: Magnetic endoscope imaging allows accurate assessment and straightening of loops during colonoscopy, but without a significant reduction in patient requirements for sedative medication or improvement in patient tolerance. However, the dosages of sedation drugs used were small.