DDW 2011 cutting edge colonoscopy techniques - state of the art lecture master class - warm water infusion/CO(2) insufflation for colonoscopy

Abstract

Pain limits the success of cecal intubation in unsedated patient. Carbon dioxide infusion instead of air insufflation and water infusion as an adjunction to air insufflation have both been investigated as modalities to minimize pain associated with colonoscopy. Multiple RCT support an effect of carbon dioxide in reducing pain after colonoscopy. A modern method of water infusion as the sole modality for aiding colonoscope insertion has been shown to reduce pain during and after colonoscopy. Favorable effects in reducing discomfort have been documented in both sedated and unsedated patients. Because of the need to perform water exchange in the patients with suboptimal bowel perparation, a serendipitous consequence of salvage cleansing is evident with application of the water method. The associated increase in adenoma detection especially in the proximal colon is most intriguing. The hypothesis that the water method during insertion combined with carbon dioxide insufflation during withdrawal will optimally decrease colonoscopy pain should be evaluated. The implications of increased adenoma detection by the water method also deserve to be studied.

Figures

Figure 1

Still images illustrating the technical details of the water method: a. air filled rectum; b. air removal collapses rectal lumen; c. infused water opens lumen; d. residual feces removed by suction; e. simultaneous water infusion and suction produce turbulence at the tip of the colonoscope to dislodge adherent feces from nearby mucosa; f & g. suction of luminal water minimizes distention; h & i. appendix opening; j & k. suction marks near appendix opening; l. difficult view due to excessive residual feces; m. insufflated air in the presence of excessive residual feces can produce air/fluid compartments to facilitate viewing of the lumen, but the preferred maneuver with the water method is water exchange to clear the view.

Figure 2

Most of the dirty water is in the suction bottle during insertion. Water exchange provides salvage cleansing of the colon.

Figure 3

Outcome of randomized controlled trial in scheduled unsedated patients. N, Air = 40; water = 42. Pain (0 = none, 10 = most severe); median scores. CIR, cecal intubation rate.

Figure 4

Outcome of randomized controlled trial in patients examined with the option of on-demand sedation. N, air = 50; water = 50. Pain (0 = none, 10 = most severe) and recovery times are median scores. Sedation medications are means. Significant difference based on Fisher's exact test, Mann-Whitney U test and unpaired t test.

Figure 5

Detection rate of

Figure 6

Head-to-head comparison of adenoma detection rate between water and air methods. N, air = 191; water = 177. Significant difference based on Fisher's exact test.

Figure 7

Potential short- and long-term outcomes (abbreviations: ER, emergency room; prep, preparation; pt, patient; tech, technician)