The American Society for Gastrointestinal Endoscopy (ASGE) has issued a report on technologies for monitoring the quality of endoscope reprocessing. Emerging technologies offer the ability to perform rapid surveillance of the quality of reprocessing, which potentially might help reinforce adherence to the many steps in reprocessing.
The report, developed by ASGE’s Technology Committee, appears in the September issue of
GIE: Gastrointestinal Endoscopy, the monthly peer-reviewed scientific journal of ASGE.
More than 20 million endoscopies are performed in the United States annually. Despite the large number of procedures performed, transmission of infection via endoscopes is very rare. Reported infections usually have been associated with a failure to follow established multisociety guidelines for reprocessing or have been attributed to defective equipment.
The manual component of reprocessing appears most prone to error. Periodic surveillance might potentially help reduce such errors by reinforcing adherence to the steps in reprocessing. However, further studies are needed to determine whether surveillance strategies can effectively identify failures of cleaning, disinfection, or storage that are not detected by process monitoring and that create a risk of transmission of infection. There are no recommendations for monitoring the efficacy of reprocessing of flexible endoscopes in the United States. This report highlights the status of current technology for monitoring the efficacy of flexible endoscope reprocessing.
Endoscope reprocessing comprises manual cleaning steps followed by high-level disinfection (HLD), then by rinsing and drying steps. Meticulous manual cleaning is imperative to achieve subsequent HLD. HLD usually comprises bedside cleaning and suctioning of enzymatic detergent followed by manual washing, flushing, and brushing of accessible channels to remove all residues. These processes were detailed in the 2011 Multisociety guideline on reprocessing flexible gastrointestinal endoscopes." HLD may be performed manually or by automated endoscope reprocessors (AERs). AERs allow for automation and standardization of several reprocessing steps and thereby minimize the risk and impact of human error.
Effective surveillance of flexible endoscope reprocessing ideally requires testing methods that allow for rapid assessment of compliance with current reprocessing standards. However, the lack of both widely accepted bioburden/microbial benchmarks and widely validated means of assessing these has limited implementation of such strategies. Potential methods for surveillance include:
Microbial culture — culturing for bacterial load.
The European Society of Gastrointestinal Endoscopy (ESGE) recommends surveillance cultures of reprocessed endoscopes at intervals of not more than three months. However, culturing for bacterial load is impractical for many endoscopy centers that might not have easy access to microbiology laboratories. In addition, the slow turnaround time (minimum 24 hours) for results does not allow for rapid reuse of the tested endoscope. Furthermore, viruses such as hepatitis B and C and HIV cannot be cultured by using standard methods.
Bioburden assays — Evaluation of residual bioburden and organic matter.
Available methods allow rapid evaluation of residual bioburden and organic matter from the endoscope channels. Methods include a test for protein residue on the surface of endoscopes, a test able to detect protein and blood residues within the biopsy channel of endoscopes, and a test to detect protein, blood, and carbohydrate residues within the biopsy channel of endoscopes.
Adenosine triphosphate (ATP) bioluminescence testing.
ATP bioluminescence is present in microorganisms and human cells and therefore offers a means of testing for microbial and biological residue.
ATP bioluminescence testing provides results within a few minutes. ATP bioluminescence was first used for measuring the cleanliness of surfaces in hospitals. Recent studies have demonstrated the measurement of ATP to be effective in monitoring HLD of flexible endoscopes. The ability to obtain immediate results is a significant advantage of ATP bioluminescence over standard microbial cultures. There are multiple ATP measurement tools available.
These technologies offer endoscopy units the ability to implement surveillance strategies, which might improve the quality of endoscope reprocessing. The data regarding technology for monitoring the efficacy of endoscope reprocessing are limited. The efficacy data for available techniques to measure residual organic material or ATP are noncomparative and small in sample size.