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Simethicone residue remains inside gastrointestinal endoscopes despite reprocessing
Cori L Ofstead1, Harry P Wetzler1, Ellen A Johnson1
1Ofstead & Associates, Inc, Saint Paul, MN.
Background:
During a study designed to assess endoscope reprocessing effectiveness, a borescope was used to examine lumens and ports. Cloudy, white, viscous fluid was observed inside fully reprocessed gastroscopes and colonoscopes. This fluid resembled simethicone, which is commonly administered to reduce foam and bubbles that impede visualization during gastrointestinal endoscopy. This article describes methods used to determine whether the observed fluid contained simethicone.
Methods:
Photographs of residual fluid were taken using a borescope. Sterile cotton-tipped swabs were used to collect samples of fluid observed in 3 endoscope ports. Samples were evaluated using Fourier transform infrared spectroscopy (FTIR)-attenuated total reflection analysis.
Results:
Residual fluid was observed inside 19 of 20 endoscopes. Fluid photographed in 8 endoscopes resembled simethicone solutions. FTIR analysis confirmed the presence of simethicone in 2 endoscopes.
Conclusions:
Fluid containing simethicone remained inside endoscopes despite reprocessing. Simethicone is an inert, hydrophobic substance that may reduce reprocessing effectiveness. Simethicone solutions commonly contain sugars and thickeners, which may contribute to microbial growth and biofilm development. Studies are needed to assess the prevalence of residual moisture and simethicone in endoscopes and determine the impact on reprocessing effectiveness. We recommend minimizing the use of simethicone pending further research into its safety.
Insights
Residual simethicone fluid was found in reprocessed endoscopes, potentially impacting cleaning effectiveness. Further research is needed to assess its prevalence and safety.
Area of Science:
- Gastroenterology
- Medical Device Reprocessing
- Analytical Chemistry
Background:
- A study assessing endoscope reprocessing found cloudy fluid in cleaned gastroscopes and colonoscopes.
- The fluid's appearance suggested it might be simethicone, an anti-foaming agent used during endoscopy.
Purpose of the Study:
- To determine if residual fluid observed in endoscopes after reprocessing contained simethicone.
- To investigate the potential impact of simethicone on endoscope reprocessing effectiveness.
Main Methods:
- Borescope examination of endoscope lumens and ports to visualize residual fluid.
- Collection of fluid samples from endoscope ports using sterile swabs.
- Analysis of collected samples using Fourier transform infrared spectroscopy (FTIR)-attenuated total reflection.
Main Results:
- Residual fluid was detected in 19 out of 20 reprocessed endoscopes.
- Fluid resembling simethicone was photographed in 8 endoscopes.
- FTIR analysis confirmed the presence of simethicone in samples from 2 endoscopes.
Conclusions:
- Simethicone can remain in endoscopes after reprocessing, posing a potential risk.
- The hydrophobic nature of simethicone may hinder effective reprocessing.
- Simethicone solutions may contain additives that promote microbial growth, necessitating further investigation and potentially reduced use.
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