Original article
Clinical endoscopy
A randomized, controlled trial comparing real-time insertion pain during colonoscopy confirmed water exchange to be superior to water immersion in enhancing patient comfort

https://doi.org/10.1016/j.gie.2014.07.029Get rights and content

Background

A recent American Society for Gastrointestinal Endoscopy Technology Status Evaluation Report recommended comparative studies of water-aided colonoscopy methods to refine the optimal insertion technique.

Objective

Air insufflation (AI), water immersion (WI), and water exchange (WE) were compared head-to-head to test the hypothesis that WE produces the least insertion pain.

Design

Patient-blinded, prospective, randomized, controlled trials.

Setting

Two community hospitals in Italy.

Patients

First-time diagnostic or screening colonoscopy in unsedated patients with the option of on-demand sedation.

Intervention

Colonoscopy with AI, WI, or WE.

Main Outcome Measurements

Real-time maximum insertion pain (0 = none, 10 = worst). To avoid interventional bias, the timing of recording was at the discretion of the nurse assistant. Adjunct measures were implemented to ensure patient perception of minimal discomfort. Recalled pain and patients’ guess of insertion methods were recorded after colonoscopy.

Results

Results were merged for 576 randomized patients. Correct patient guesses lower than 33% confirmed adequate blinding. Significant correlation (Pearson coefficient 0.6, P < .0005) between real-time and recalled pain provided internal validation of the former as the primary outcome. Real-time pain (95% confidence interval [CI]: AI, 4.1 [3.7-4.5]; WI, 3.5 [3.0-3.9]; and WE, 2.5 [2.2-2.9] [P < .0005] was the lowest in the WE group. The proportions of patients completing unsedated colonoscopy based on the assigned methods were significantly different (WE, 74.7% vs WI, 62.4%; P = .009; vs AI, 65.3%; P = .04). WE required the least implementation of adjunct maneuvers.

Limitations

Unblinded colonoscopists.

Conclusion

The current findings with an internally validated primary outcome in adequately blinded patients support the hypothesis that WE is superior to WI in attenuating real-time insertion pain and enhancing completion of unsedated colonoscopy.

Section snippets

Materials and methods

To ensure adequate stratified recruitment, we set up 2 similarly designed RCTs at 2 centers that simultaneously enrolled and randomized both diagnostic (NCT01781650) and screening patients (NCT01780818) at each site.

The RCTs were discussed with the respective local ethics committees, registered at Clinicaltrial.gov, and conducted according to the principles of the Declaration of Helsinki and Good Clinical Practice Guidelines. Written informed consent was obtained from all patients. F.W.L. was

Results

Based on similar protocol, the 2 datasets in diagnostic and screening cases, respectively, were combined and analyzed. A total of 576 patients were randomly allocated to AI (n = 193), WI (n = 197), or WE (n = 186). Demographic and baseline data were comparable (Table 1).

Discussion

Real-time maximum insertion pain scores during colonoscopy obtained in an unblinded manner were validated by comparison with recalled pain scores after colonoscopy obtained in a blinded manner.7, 20, 21, 22 Real-time maximum insertion pain scores were significantly correlated with recalled pain.7, 20, 21, 22 The successful reduction of recalled pain, as suggested previously,16 was confirmed in the AI group with a mean (95% CI) recalled pain score of 1.9 (1.5-2.2) compared with 2.3 (2.0-2.5)

References (27)

  • T. Rabenstein et al.

    Warm water infusion colonoscopy: a review and meta-analysis

    Endoscopy

    (2012)
  • A. Amato et al.

    Carbon dioxide insufflation or warm-water infusion versus standard air insufflation for unsedated colonoscopy: a randomized controlled trial

    Dis Colon Rectum

    (2013)
  • S. Cadoni et al.

    A two center randomized controlled trial of water-aided colonoscopy versus air insufflation colonoscopy

    Endoscopy

    (2014)

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    DISCLOSURE: All authors disclosed no financial relationships relevant to this article.

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