A prospective randomized controlled trial of the safety and efficacy of carbon dioxide insufflation compared with room air insufflation during gastric endoscopic submucosal dissection.

BACKGROUND AND AIM Carbon dioxide (CO2 ) insufflation during gastric endoscopic submucosal dissection (GESD) under sedation can be used instead of room air insufflation. Appropriate monitoring of the partial pressure of CO2 during GESD is necessary due to the impaired respiration. The aim of this study was to assess the safety and efficacy of CO2 insufflation during GESD compared with conventional room air insufflation. METHODS Patients with a gastric epithelial neoplasm or early gastric cancer were enrolled. A total of 76 consecutive patients were randomly assigned to the CO2 insufflation group (CO2 group) or the room air insufflation group (air group). The primary outcome was the mean difference of end-tidal CO2 (EtCO2 ) between two groups. RESULTS The upper bound of the 95% CI for the mean EtCO2 difference between the two groups before the procedure and at 15, 30 and 45 min after insufflation met the criteria for noninferiority. In a subgroup analysis of patients 70 years and older, the mean difference of EtCO2 was not significantly different between two groups. However, the air group received more analgesics than the CO2 group after the procedure (67.6% vs 35.1%, P = 0.005). In addition, in terms of improvement of abdominal pain or bowel gas after 24 h of GESD, CO2 group showed better results than air group (both P < 0.05). CONCLUSIONS CO2 insufflation during GESD is as safe as using room air, and patients, including elderly patients, receiving CO2 achieve more rapid relief of abdominal pain and intra-abdominal residual gas during and after the procedure.