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

Abstract

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

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

Methods: 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.

Results: 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.

Conclusions: 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.