It's All About the Bubbles: Assessing the Effects of Simethicone on Safety and Efficacy During Colonoscopy

Theoretical infection concerns prompted national Department of Veterans Affairs guidance prohibiting simethicone use in colonoscope reservoirs on January 1, 2024.

We sought to determine if reservoir simethicone is associated with post-procedure infection and impact on procedure time, sedation usage, and adenoma detection rate.

We conducted a retrospective cohort study of all-comers undergoing colonoscopy at Houston's Veterans Affairs hospital during September 1-30, 2023 (reservoir simethicone) and April 1-30, 2024 (aliquots administered on request [channel simethicone]). Primary outcomes were mean withdrawal and cecal intubation times. Secondary outcomes were adenoma detection rate, post-procedure 30-day infection rate, and sedation usage. We adjusted for covariates and used linear regression to determine significant predictors for mean withdrawal and intubation times.

Of 446 total colonoscopies, 211 used reservoir simethicone (47.3%) and 235 (52.7%) used channel simethicone. Mean intubation time was 8.3 min [SD ± 6.5] in the reservoir group and 9.9 min [SD ± 8.4] in the channel group (p = 0.03). Mean withdrawal time was 17.4 min [SD ± 10.2] in the reservoir group and 20.9 min [SD ± 11.9] in the channel group (p = < 0.01). Reservoir group procedures required less midazolam (p = 0.01) and fentanyl (p = 0.02). Post-operative infection (n = 1 vs n = 0; p = 0.47) and adenoma detection rate (p = 0.92) differences were not significant.

Reservoir simethicone was significantly associated with shorter intubation and withdrawal times and lower sedation usage, even after adjusting for covariates, suggesting increased efficiency with comparable infection risk.