Evaluation of abdominal circumference and salivary amylase activities after unsedated colonoscopy using carbon dioxide and air insufflations.

Objective To assess and compare abdominal distention and stress in unsedated colonoscopy using carbon dioxide (CO₂) and air insufflations. Methods Two hundred and five patients underwent colonoscopic examinations without sedation using either CO₂ or air insufflation. Abdominal circumference and salivary amylase (sAMY) activities before and 0 and 15 min after colonoscopy were measured by a nurse who was blinded to the grouping of the patients. Results In all, 102 and 103 patients were randomly recruited in the CO₂ and air insufflation groups, respectively. sAMY activities before and 0 and 15 min after colonoscopy were not significantly different between the two groups. Abdominal circumference measured immediately and 15 min after colonoscopy was significantly smaller in CO₂ insufflation group than in the air insufflation group (81.2 cm vs 84.0 cm, and 79.7 cm vs 83.6 cm, respectively; P <0.05). The increasing ratio of abdominal circumference immediately after colonoscopy was not significantly different between the two groups; however, the ratio at 15 min after colonoscopy using CO₂ insufflation was significantly lower than that in the air insufflation group (1.007 vs 1.028, P <0.001). Conclusion sAMY activities after unsedated colonoscopy using CO₂ insufflation were not improved; however, CO₂ insufflation decreases abdominal circumference after colonoscopy compared with air insufflation. [ABSTRACT FROM AUTHOR]