Abstract
BACKGROUND: Adequately powered studies in children are scarce and there are reports on the risk of carbon dioxide (CO2) retention after colonoscopy. PURPOSE: This study investigated the efficacy and safety of CO2 insufflation in children undergoing colonoscopy. METHODS: This prospective randomized clinical trial was conducted at a tertiary care hospital between March 2023 and July 2024. We recruited 200 consecutive children (age, 5-18 years; n=100 in each arm) who underwent colonoscopy under conscious sedation. Patients were randomized to receive CO2 or room air using a random number table. The primary outcome measure was postprocedural pain assessed by using a visual analogue scale (VAS). Secondary outcome measures included time to reach the cecum, total procedure duration, abdominal distension, and end-tidal (ET) CO2 level. Complications were recorded. RESULTS: Pain scores at 2 and 4 hours postprocedure were significantly lower in the CO2 versus room-air group (1.12 vs. 1.66, P=0.001 at 2 hours and 0.37 vs. 0.61, P=0.002 at 4 hours). The time to reach the cecum was significantly higher in the CO2 group (39.6 vs. 26.6 min, P=0.01). A greater proportion of children in the room-air group (29% vs. 19%, P=0.04) reported significant pain (VAS score, ≥3). The subgroup analysis revealed a significantly longer time to reach the cecum and total procedure duration in the CO2 group among first-year trainees. ET-CO2 levels were significantly higher in the CO2 group (36 [interquartile range, 35-37] mmHg vs. 34 [interquartile range, 32-35] mmHg, P=0.001), but none developed any signs of CO2 retention. No significant intergroup differences were noted in abdominal girth, bloating sensation, analgesic requirements, or procedure-related complications. CONCLUSIONS: CO2 insufflation is safer and makes the procedure less painful but slower than room-air insufflation, especially in first-year trainees, without an increased risk of retention.