Safe storage time for reprocessed flexible endoscopes: a systematic review

Flexible endoscopes are used to diagnose and treat gastrointestinal and pulmonary diseases. They have narrow, internal channels which are used to insert instruments, air and water into hollow organs and to remove tissues and secretions. Since endoscopes are contaminated during use and have heat sensitive components that cannot be sterilized, they are reprocessed with cleaning and high-level disinfection to destroy microorganisms. Knowing how long reprocessed endoscopes can be safely stored is essential for preventing infection and decreasing unnecessary costs.

The objective was to systematically review the best available evidence related to safe storage time (in days) of flexible endoscopes that have undergone reprocessing in order to determine when they can be safely used again without posing any risk of contamination from pathogens.

The types of equipment were flexible endoscopes that had been reprocessed according to recommended guidelines, stored for a specified period of time, and tested for microorganisms.The intervention was the length of time (in days) that reprocessed endoscopes were appropriately stored before use.This review included non-randomized controlled trials and prospective cohort studies.This review considered studies that included the outcome measure: microbial growth on endoscopes which was measured with microbiological cultures.

The search strategy aimed to find studies in English and Spanish and included published and unpublished studies from 1990 to 2014. An initial search of CINAHL, MEDLINE/PUBMed and EMBASE was conducted followed by an analysis of the text words contained in the title and abstract and index terms used to describe the articles. Next, a search using all identified keywords and index terms was undertaken across all included databases. Then, the reference lists of all identified reports and articles were searched for additional studies. A citation search was performed in order to find additional studies that cited those already located.

The Joanna Briggs Institute's critical appraisal instruments were used to assess methodological quality.

Data were extracted from studies in the review using the Joanna Briggs Institute data extraction form.

Since the findings were expressed using descriptive statistics, a meta-analysis was impossible. Therefore, the findings have been summarized in a narrative form with tables and a figure.

Ten studies met the appraisal criteria and were included in the review. Storage time ranged from two to 56 days, and all 10 studies concluded that endoscopes could safely be stored for the time measured. Seven studies measured microbial growth in all channels; six involved storing the endoscopes for at least three days and five for at least seven days. The contamination rates were low (2% at three days and 4% at seven days) and pathogens were rare. The contamination rate remained consistent over time.

Endoscopes can be stored for seven days if they have been effectively reprocessed and appropriately stored. Ongoing surveillance cultures are necessary to verify reprocessing effectiveness.