Retrospective Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. Jan 25, 2016; 8(2): 113-121
Published online Jan 25, 2016. doi: 10.4253/wjge.v8.i2.113
Evidence to suggest adoption of water exchange deserves broader consideration: Its pain alleviating impact occurs in 90% of investigators
Sergio Cadoni, Mauro Liggi, Premysl Falt, Stefano Sanna, Mariangela Argiolas, Viviana Fanari, Paolo Gallittu, Donatella Mura, Maria L Porcedda, Vit Smajstrla, Matteo Erriu, Felix W Leung
Sergio Cadoni, Mauro Liggi, Paolo Gallittu, Donatella Mura, Digestive Endoscopy Unit, St. Barbara Hospital, 09016 Iglesias, Italy
Premysl Falt, Vit Smajstrla, Digestive Diseases Center, Vitkovice Hospital, 703 84 Ostrava, Czech Republic
Stefano Sanna, Mariangela Argiolas, Viviana Fanari, Maria L Porcedda, Digestive Endoscopy Unit, N. S. di Bonaria Hospital, 09037 San Gavino Monreale, Italy
Matteo Erriu, Department of Surgical Sciences, University of Cagliari, 09121 Cagliari, Italy
Felix W Leung, Sepulveda Ambulatory Care Center, Veterans Affairs Greater Los Angeles Healthcare System, North Hills, CA 91343, United States
Felix W Leung, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90024, United States
Author contributions: Cadoni S, Liggi M, Falt P and Leung FW defined the research theme, designed methods, interpreted the results and wrote the paper; Cadoni S, Liggi M, Falt P, Sanna S, Argiolas M, Fanari V, Gallittu P, Mura D, Porcedda ML and Smajstrla V contributed to the acquisition and interpretation of data, drafting and critical revision of the manuscript for important intellectual content; Erriu M did the statistical analysis of the data; all the authors have approved the final draft submitted.
Institutional review board statement: The study protocols relative to this retrospective study and the use of their data were reviewed and approved by the local Ethics Committee of the St. Barbara Hospital, Vitkovice Hospital and N. S. di Bonaria Hospital.
Informed consent statement: Patients agreed to the study by written consent at enrollment, even if the analysis used anonymous clinical data. For full disclosure, the details of the study are published on the website of the Institution of the St. Barbara Hospital under the section “Archivio Delibere” (Resolutions Archive).
Conflict-of-interest statement: The authors declare no conflicts of interest regarding this manuscript.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Sergio Cadoni, MD, Digestive Endoscopy Unit, St. Barbara Hospital, Via San Leonardo 1, 09016 Iglesias, Italy.
Telephone: +39-0781-3922858 Fax: +39-0781-3922323
Received: June 15, 2015
Peer-review started: June 30, 2015
First decision: July 31, 2015
Revised: August 18, 2015
Accepted: December 13, 2015
Article in press: December 15, 2015
Published online: January 25, 2016

AIM: To determine whether observations were reproducible among investigators.

METHODS: From March 2013 through June 2014, 18-85-year-old diagnostic and 50-70-year-old screening patients were enrolled at each center to on-demand sedation colonoscopy with water exchange (WE), water immersion (WI) and insufflation with air or CO2 for insertion and withdrawal [air or carbon dioxide (AICD)]. Data were aggregated for analysis. Primary outcome: Variations in real-time maximum insertion pain (0 = none, 1-2 = discomfort, 10 = worst).

RESULTS: One thousand and ninety-one cases analyzed: WE (n = 371); WI (n = 338); AICD (n = 382). Demographics and indications were comparable. The WE group had the lowest real-time maximum insertion pain score, mean (95%CI): WE 2.8 (2.6-3.0), WI 3.8 (3.5-4.1) and AICD 4.4 (4.1-4.7), P < 0.0005. Ninety percent of the colonoscopists were able to use water exchange to significantly decrease maximum insertion pain scores. One investigator had high insertion pain in all groups, nonetheless WE achieved the lowest real-time maximum insertion pain score. WE had the highest proportions of patients with painless unsedated colonoscopy (vs WI, P = 0.013; vs AICD, P < 0.0005); unsedated colonoscopy with only minor discomfort (vs AICD, P < 0.0005), and completion without sedation (vs AICD, P < 0.0005).

CONCLUSION: Aggregate data confirm superiority of WE in lowering colonoscopy real-time maximum insertion pain and need for sedation. Ninety percent of investigators were able to use water exchange to significantly decrease maximum insertion pain scores. Our results suggest that the technique deserves consideration in a broader scale.

Keywords: Colonoscopy, Painless colonoscopy, Water immersion, Water exchange, Colonoscopy pain

Core tip: Randomized controlled trials (RCTs) have shown water exchange (WE) to have considerable advantage in decreasing colonoscopy insertion pain. Assessment of individual investigators’ performance using WE in RCTs is usually not reported. We assessed the performance of individual investigators in 3 RCTs comparing WE, water immersion and gas insufflation (with air or carbon dioxide) during insertion, to determine whether observations are reproducible across investigators and what factors might contribute to variations. Aggregate data show that individual investigators had significant variations in insertion pain scores and use of adjunct maneuvers together with short insertion time, but the pain alleviating impact of WE occurs in 90% of them. WE has the highest proportions of patients with painless unsedated colonoscopy; complete unsedated colonoscopy with only minor discomfort and completion without sedation.