Original articleClinical endoscopyCarbon dioxide insufflation compared with air insufflation in double-balloon enteroscopy: a prospective, randomized, double-blind trial

BackgroundFew studies have evaluated the degree of pain, the amount of retained gas, and the safety of carbon dioxide (CO2) insufflation in patients undergoing double-balloon enteroscopy (DBE).ObjectiveTo clarify the usefulness and safety of CO2 insufflation during DBE.DesignSingle-center, prospective, randomized, double-blind, controlled trial.SettingUniversity hospital.PatientsForty eligible patients with small-bowel disease for whom DBE was indicated were randomized to a CO2 insufflation (CO2) group or an air insufflation (air) group by means of sealed envelopes.InterventionDBE with insufflation of CO2 or air.Main Outcome MeasurementsEfficacy evaluation was based on the degree of pain as assessed by use of a visual analog scale (VAS) and the amount of residual gas retention within the small and large bowels on radiography. The safety of CO2 insufflation was evaluated by arterial blood gas analysis.ResultsSignificantly fewer patients in the CO2 group had severe pain of ≥50 mm on the VAS during DBE than in the air group (P = .02). Significantly less gas was retained in the small bowel just after and at 3 hours after DBE in the CO2 group than in the air group (P = .003, P = .01, respectively). There was significantly less residual gas retention in the large bowel at 3 hours after DBE in the CO2 group than in the air group (P = .02). There was no significant difference in pre-DBE and post-DBE partial pressure of oxygen in the blood (PaO2) and partial pressure of carbon dioxide in the blood (PaCO2) between groups.LimitationsSmall sample size.ConclusionCO2 insufflation is a safe and useful procedure when performed during DBE.