Carbon Dioxide Insufflation in Routine Colonoscopy Is Safe and More Comfortable: Results of a Randomized Controlled Double-Blinded Trial

Many patients experience pain and discomfort after colonoscopy. Carbon dioxide (CO 2 ) can reduce periprocedural pain although air insufflation remained the standard procedure. The objective of this double-blinded, randomized controlled trial was to evaluate whether CO 2 insufflation does decrease pain and bloating during and after colonoscopy compared to room air. Methods . 219 consecutive patients undergoing colonoscopy were randomized to either CO 2 or air insufflation. Propofol was used in all patients for sedation. Transcutaneous CO 2 was continuously measured with a capnograph as a safety parameter. Pain, bloating, and overall satisfaction were assessed at regular intervals before and after the procedure. Results(data are mean ± SD) . 110 patients were randomized to CO 2 and 109 to room air. The baseline characteristics were similar in both groups. The mean propofol dose was not different between the treatments, as were the time to reach the ileum and the withdrawal time. pCO 2 at the end of the procedure was 35.2 ± 4.3 mmHg (CO 2 group) versus 35.6 ± 6.0 mmHg in the room air group ( P > .05). No relevant complication occurred in either group. There was significantly less bloating for the CO 2 group during the postprocedural recovery period ( P < .001) and over the 24-hour period ( P < .001). Also, patients with CO 2 insufflation experienced significantly less pain ( P = .014). Finally, a higher overall satisfaction ( P = .04 ) was found in the CO 2 group. Conclusions . This trial provides compelling evidence that CO 2 insufflation significantly reduces bloating and pain after routine colonoscopy in propofol-sedated patients. The procedure is safe with no significant differences in CO 2 between the two groups.