Water exchange versus carbon dioxide insufflation in unsedated colonoscopy: a multicenter randomized controlled trial
submitted 04 April 2014
accepted after revision 15 September 2014
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.
- 1 Cohen LB, Ladas SD, Vargo JJ et al. Sedation in digestive endoscopy: the Athens international position statements. Aliment Pharmacol Ther 2010; 32: 425-442
- 2 Wu J, Hu B. The role of carbon dioxide insufflation in colonoscopy: a systematic review and meta-analysis. Endoscopy 2012; 44: 128-136
- 3 Leung JW, Mann SK, Siao-Salera R et al. A randomized, controlled comparison of warm water infusion in lieu of air insufflation versus air insufflation for aiding colonoscopy insertion in sedated patients undergoing colorectal cancer screening and surveillance. Gastrointest Endosc 2009; 70: 505-510
- 4 Leung FW, Harker JO, Jackson G et al. A proof-of-principle, prospective, randomized, controlled trial demonstrating improved outcomes in scheduled unsedated colonoscopy by the water method. Gastrointest Endosc 2010; 72: 693-700
- 5 Leung J, Mann S, Siao-Salera R et al. A randomized, controlled trial to confirm the beneficial effects of the water method on U.S. veterans undergoing colonoscopy with the option of on-demand sedation. Gastrointest Endosc 2011; 73: 103-110
- 6 Falt P, Liberda M, Smajstrla V et al. Combination of water immersion and carbon dioxide insufflation for minimal sedation colonoscopy: a prospective, randomized, single-center trial. Eur J Gastroenterol Hepatol 2012; 24: 971-977
- 7 Amato A, Radaelli F, Paggi S et al. Carbon dioxide insufflation or warm-water infusion versus standard air insufflation for unsedated colonoscopy: a randomized controlled trial. Dis Colon Rectum 2013; 56: 511-518
- 8 Rabenstein T, Radaelli F, Zolk O. Warm water infusion colonoscopy: a review and meta-analysis. Endoscopy 2012; 44: 940-951
- 9 Garborg KK, Loberg M, Matre J et al. Reduced pain during screening colonoscopy with an ultrathin colonoscope: a randomized controlled trial. Endoscopy 2012; 44: 740-746
- 10 Calderwood AH, Jacobson BC. Comprehensive validation of the Boston Bowel Preparation Scale. Gastrointest Endosc 2010; 72: 686-692
- 11 Hoff G, Bretthauer M, Huppertz-Hauss G et al. The Norwegian Gastronet project: continuous quality improvement of colonoscopy in 14 Norwegian centres. Scand J Gastroenterol 2006; 41: 481-487
- 12 Kaminski MF, Bretthauer M, Zauber AG et al. The NordICC Study: rationale and design of a randomized trial on colonoscopy screening for colorectal cancer. Endoscopy 2012; 44: 695-702
- 13 Leung FW, Leung JW, Mann SK et al. The water method significantly enhances patient-centered outcomes in sedated and unsedated colonoscopy. Endoscopy 2011; 43: 816-821
- 14 Bretthauer M, Thiis-Evensen E, Huppertz-Hauss G et al. NORCCAP (Norwegian colorectal cancer prevention): a randomised trial to assess the safety and efficacy of carbon dioxide versus air insufflation in colonoscopy. Gut 2002; 50: 604-607
- 15 Bretthauer M, Lynge AB, Thiis-Evensen E et al. Carbon dioxide insufflation in colonoscopy: safe and effective in sedated patients. Endoscopy 2005; 37: 706-709
- 16 Ferreira-Valente MA, Pais-Ribeiro JL, Jensen MP. Validity of four pain intensity rating scales. Pain 2011; 152: 2399-2404
- 17 Cadoni S, Gallittu P, Sanna S et al. A two-center randomized controlled trial of water-aided colonoscopy versus air insufflation colonoscopy. Endoscopy 2014; 46: 212-218
- 18 Ramirez FC, Leung FW. The water method for aiding colonoscope insertion: the learning curve of an experienced colonoscopist. J Interv Gastroenterol 2011; 1: 97-101
- 19 Fischer LS, Lumsden A, Leung FW. Water exchange method for colonoscopy: learning curve of an experienced colonoscopist in a U.S. community practice setting. J Interv Gastroenterol 2012; 2: 128-132
- 20 Rex DK, Bond JH, Winawer S et al. Quality in the technical performance of colonoscopy and the continuous quality improvement process for colonoscopy: recommendations of the U.S. Multi-Society Task Force on Colorectal Cancer. Am J Gastroenterol 2002; 97: 1296-1308
- 21 Kaminski MF, Regula J, Kraszewska E et al. Quality indicators for colonoscopy and the risk of interval cancer. N Engl J Med 2010; 362: 1795-1803