EFHSS Questions and Answers - Question Q00235

Has anyone done any research in to the length of time endoscopes can be used after sterilisation in a Steris 1 system and dried with 70% alcohol and stored in a cupboard with all channels open. Currently my Unit is reprocessing all endoscopes just prior to use. It has been suggested that they are safe to use 24 hours post sterilization. We mainly do gastroscopies and colonoscopies.


Thank you for your time.
Debbie Black
Associate Nurse Unit Manager Day Procedure Unit
Goulburn Valley Health Shepparton
Australia

Debbie,

The department of Gastro-enterology of the hospital I work in, gave me the following article on the microbiological safety after reprocessing of endoscopes. The article is not about the steris system but the principles stay the same. May I point your attention on the following important general recommendation: If you use an automated washer-disinfector for endoscopes that does not include an adequate drying phase, like after manual disinfection, the instrument must be disinfected again if it has not been in use for longer than 4 hours (WIP guideline 21b, Cleaning and disinfection of endoscopes, see the EFHSS Education page).

Wim Renders


Bacteriologic control of endoscopic high-level disinfection efficacy
Ludmilla Pavlatova, Pavel Cermak, Stanlislav Rejchtr, Jan Bures
Charles Univ. Teaching Hospital, Hradec Kralove, Czech Republic

Background. There are several clear guidelines for flexible endoscope reprocessing and disinfection. However, there are no definitive and ultimate data available concerning long-term microbiological safety of endoscope storage.
Aim of the study was to perform a long-term bacteriologic follow-up of flexible endoscopes after their high-level disinfection.
Methods. Different types of endoscopes were tested (gastroscope, therapeutic duodenoscope and colonoscope). Having finished the examination endoscope was subjeced to an initial decontamination including wiping surface with disinfectant (Secusept) and flushing of the channels with water and disinfectant solution (Secusept). This initial step was followed by manual cleaning (brushing and flushing) in immersion of detergent. Then endoscopes were put into an automatic flexible endoscope reprocessor (endo-thermo-disinfector ETD-2 Olympus) providing high-level disinfection using detergent and glutaraldehyde-based solution (Cidex). Bacteriologic assays were done immediately after the high-level disinfection and every day for the following five days. Endoscopes were stored hanging in a dustproof cabinet. Bacteriologic smears were obtained from endoscope surface, valves and the working channels. Bacteriologic smears were cultured immediately after their collection for all kinds of bacteria including bacterial spores and for Candida Sp.
A total number of 135 bacteriologic assays were performed.
Results. All endoscopes were bacteria-free immediately after their high-level disinfection in all assays. Only four assays were positive during subsequent five-days follow-up: valve of therapeutic duodenoscope in the second day of follow-up (Corinebacterium pseudodiphteriae), valve of another therapeutic duodenoscope on the thirth of the follow-up (Staphylococcus epidermidis) and valve and working channel of the same gastroscope on the second and thirth day of follow-up ( Staphylococcus epidermidis).
Conclusions. Endoscopes for procedures associated with a higher risk of infection (ERCP) sclerotherapy, percutaneous gastrostomy placement) should be re-disinfected just before the examination. Other methods of gastro-intestinal endoscopy can use endoscopes disinfected up to five days before without any need of subsequent re-disinfection.

Pavlatova Ludmila
Endoscopy Unit, 2 Dept. of Medicine Charles University Teaching Hospital
Adress: Sokolska
City: 500 05 Hradec Kralove
Country: Czech Republic
E-mail:

Debbie,

In general Wim Renders is correct and this is indeed the protocol we have observed during our HTM 2030 validation work. There is however another dimension to this problem and it involves Biofilms. Until such time as routine protocols are introduced to remove and eradicate biofilms from the biopsy / irrigation channels of endoscopes they cannot be considered sterile. Work has progressed in this area and published data is available [www.processtech.co.uk] Microbiology on the channels of in service endoscopes reveals they can support micro-organisms for up to 8 weeks during storage despite them being cleaned and alcohol flushed many times during normal service. Work is continuing in this area and in the area of endoscope storage. The encouraging part of the study shows that simple soak protocols in electrolysed brine solutions can remove and control the formation of biofilm.

Jim Daly M.D. for Medipure Ltd