The Impact of Warmed Carbon Dioxide Insufflation During Colonoscopy on Polyp Detection

Colorectal cancer is the second most common cancer in the world and the second leading cause of cancer-related mortality. Colorectal cancers arise from precursor adenomatous polyps in a well characterized adenoma to carcinoma progression. The removal of such precursor lesions reduces colorectal cancer mortality between 30 to 50%. Colonoscopy is used for detection of neoplastic polyps but significant miss rates of such lesions are reported. Methods to reduce spasm of the colon have been investigated to increase adenoma detection rates including the use of warm water irrigation and hyoscine butyl bromide. Carbon dioxide warmed to body temperature is postulated to have spasmolytic effects. Administration of warmed carbon dioxide during colonoscopy may improve polyp detection.

Objective: In this study, colonoscopy using warmed carbon dioxide insufflation will be compared to standard room temperature air insufflation to see if there is a greater detection of polyps per patient.

Methods: Patients undergoing colonoscopy for screening and surveillance indications will be included and randomized to receive either room temperature room air or warmed carbon dioxide (37 degrees Celsius). Endoscopists and patients will be blinded to the intervention. Data on indication, preparation, sedation, withdrawal time will be recorded. Polyp detection rate will be the primary outcome. Secondary outcomes will include adenoma detection rate and advanced lesion detection rates.