[Safety and efficacy of carbon dioxide insufflation during colonoscopy].

OBJECTIVE:To assess the safety and efficacy of carbon dioxide (CO(2)) in colonoscopy examination. METHODS:We randomized 349 patients to undergo colonoscopy with insufflation of air (n=175) or CO(2) (n=174). At colonoscopy, p (ET CO(2)) was observed at 4 time points: before the exam, arrived caecum, back rectum, and after the exam. Patient's experience of pain in the end and after the examination at 1, 3, 6, and 24 h was registered using a visual analog scale (VAS). Sedation was not used routinely. RESULTS:The groups were similar in age, sex, inspection time, and caecal intubation rate (all P>0.05). There were no significant differences in p (ET CO(2)) values between the 2 groups before and after the procedure (all P>0.05). VAS scores in the CO(2) group at various time points after the examination were significantly lower than those in the air group (all P<0.05). The percent of VAS scores of 0 in the CO(2) group after 1, 3, 6, and 24 h was significantly higher than that in the air group (all P<0.01). CONCLUSION:Injection of CO(2) for colonoscopy will not cause CO(2) retention, and it may significantly reduce the pain, which is safe and effective.