CO2 insufflation during colonoscopy decreases post-interventional pain in deeply sedated patients: a randomized...

Air insufflation during colonoscopy is considered the standard method in most endoscopic centers. Notably, several studies have reported reduced abdominal pain after colonoscopy with CO2 insufflation in unsedated and in lightly sedated patients. The present study was designed to assess the efficacy of CO2 insufflation after colonoscopy in moderately and deeply sedated patients. We also evaluated whether CO2 insufflation increases patients' compliance for colorectal cancer screening.

A total of 300 consecutive patients allocated to colonoscopy were randomly assigned to either CO2 or air insufflation. Propofol was titrated to a level of deep sedation and propofol combined with midazolam was used for moderate sedation. Post-interventional pain levels and satisfaction with the procedure were registered on a 10-point visual analog scale. Compliance for colorectal cancer screening was ascertained separately.

CO2 insufflation was used during colonoscopy in 157 patients; conventional air was used in 143 patients. The two groups were comparable with regard to age, sex and body mass index. Neither major nor minor complications were observed. Pain sensation was significantly lower in the CO2 group at 15 min, 30 min and 6 h after colonoscopy (P<0.01); at 12 h no difference was observed. In contrast, levels of patient satisfaction did not show any significant difference. Voluntary colorectal cancer screening appeared not to be influenced by the type of insufflation gas used.

CO2 insufflation in deeply and moderately sedated patients during colonoscopy has no impact on patients' satisfaction with the procedure or on their attitude to voluntary colorectal cancer screening. However, the use of CO2 insufflation significantly diminishes abdominal pain after colonoscopy.