Endoscopy 2015; 47(03): 192-199
DOI: 10.1055/s-0034-1390795
Original article
© Georg Thieme Verlag KG Stuttgart · New York

Water exchange versus carbon dioxide insufflation in unsedated colonoscopy: a multicenter randomized controlled trial

Kjetil Garborg
1  Department of Medicine, Sorlandet Hospital HF, Kristiansand, Norway
2  Institute of Health and Society, University of Oslo, Oslo, Norway
,
Michal F. Kaminski
3  Department of Gastroenterological Oncology, Medical Center for Postgraduate Education and Institute of Oncology, Warsaw, Poland
,
Wolfgang Lindenburger
4  Department of Medicine, Sorlandet Hospital HF, Arendal, Norway
,
Håvard Wiig
1  Department of Medicine, Sorlandet Hospital HF, Kristiansand, Norway
4  Department of Medicine, Sorlandet Hospital HF, Arendal, Norway
,
Audun Hasund
1  Department of Medicine, Sorlandet Hospital HF, Kristiansand, Norway
,
Ewa Wronska
3  Department of Gastroenterological Oncology, Medical Center for Postgraduate Education and Institute of Oncology, Warsaw, Poland
,
Rolf Bruun Bie
5  Department of Pathology, Sorlandet Hospital HF, Kristiansand, Norway
,
Britta Kleist
5  Department of Pathology, Sorlandet Hospital HF, Kristiansand, Norway
,
Leif Løvdal
5  Department of Pathology, Sorlandet Hospital HF, Kristiansand, Norway
,
Øyvind Holme
1  Department of Medicine, Sorlandet Hospital HF, Kristiansand, Norway
2  Institute of Health and Society, University of Oslo, Oslo, Norway
,
Mette Kalager
2  Institute of Health and Society, University of Oslo, Oslo, Norway
6  Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, USA
7  Department of Research, Telemark Hospital, Skien, Norway
,
Geir Hoff
2  Institute of Health and Society, University of Oslo, Oslo, Norway
7  Department of Research, Telemark Hospital, Skien, Norway
8  Cancer Registry of Norway, Oslo, Norway
,
Michael Bretthauer
2  Institute of Health and Society, University of Oslo, Oslo, Norway
9  Department of Transplantation Medicine, Oslo University Hospital, Oslo, Norway
› Author Affiliations
Further Information

Publication History

submitted 04 April 2014

accepted after revision 15 September 2014

Publication Date:
20 November 2014 (online)

Background and study aims: Compared with air insufflation, water exchange and carbon dioxide (CO2) insufflation have been shown to reduce colonoscopy discomfort; however, head-to-head studies of the two methods are lacking. We aimed to compare water exchange and CO2 insufflation directly with regard to pain during primary unsedated colonoscopy.

Methods: Patients willing to undergo unsedated colonoscopy at three centers in Norway and Poland were randomized 1:1 to water exchange or CO2 insufflation during colonoscope insertion. Patients were blinded to group allocation. The primary end point was the proportion of patients reporting moderate or severe procedural pain on a 4-point verbal rating scale (VRS-4) at discharge. Secondary outcomes included the proportion of patients reporting no pain on the VRS-4.

Results: A total of 473 patients were randomized. A discharge pain questionnaire was completed by 226 of 234 patients (97 %) in the water exchange group versus 226 of 239 patients (95 %) in the CO2 group (P = 0.37). Moderate or severe pain was reported by 47 of 226 patients (21 %) in the water exchange group versus 60 of 226 patients (27 %) in the CO2 group (P = 0.15). No pain was reported by 100 of 226 patients (44 %) and 69 of 226 patients (31 %) in the water exchange and CO2 groups, respectively (P = 0.003). On-demand sedation was used in 15 patients (6 %) in each group (P = 0.95).

Conclusions: There was no significant reduction in moderate or severe pain in a comparison of water exchange with CO2 insufflation. The secondary outcome of no pain was significantly more frequent in the water exchange group. 

Clinical trials registry number: NCT01633333.