Endoscope Drying and Storage Cabinet Guidelines

Endoscopes are complex instruments with long, narrow channels that can be difficult to clean and prepare for next procedure. Helping prevent patient infections requires endoscope reprocessing after each use, following a process outlined by the device's instructions for use (IFUs). In addition, many facilities follow recommendations from organizations like ANSI/AAMI, AORN, and SGNA to guide the facilities' approach. Proper point-of-use treatment, manual cleaning, high level disinfection (HLD) or sterilization, endoscope drying and storage are critical to ensure devices are ready for patient use.

This article covers the following topics:

• The importance of endoscope drying and storage
• Standards and guidelines for endoscope drying & storage
• How do you dry an endoscope
• How long it can take to dry an endoscope
• What is an endoscope drying & storage cabinet
• How long can an endoscope be stored (also known as hang time)
• How do you transport an endoscope

The Importance of Proper Endoscope Drying and Storage

While proper storage and drying of endoscopes has received renewed attention from standards organizations in recent years, the critical nature of these practices is not new. More than 40 years ago, Gerding, Peterson, and Vennes published a study in the Gastroenterology journal, noting that forced air drying before storage significantly reduced contamination rates¹.

Residual fluid in an endoscope, or any surgical device, can enable biofilm formation, where microorganisms flourish and contribute to possible infection outbreaks⁵. Thorough drying following reprocessing helps to prevent bacteria growth and potential transmission to patients.

Standards and Guidelines for Endoscope Drying and Storage

Following up-to-date endoscope storage cabinet guidelines and standards is critical for healthcare facilities seeking to optimize reprocessing workflows and ensure patient safety. All major endoscopy (GI) governing bodies and organizations provide standards and guidance for drying and storage.

ANSI/AAMI ST91

The 2021 revision of ANSI/AAMI ST91 provides updated endoscope drying cabinet standards and other considerations, which include:

• Actively drying endoscope channels with forced air flow (instrument quality or HEPA-filtered) directed into the lumens using a direct channel attachment for at least 10 minutes.
• Storing in drying cabinets that continually circulate air through endoscopes
• Avoiding the use of syringes for channel drying
• Endoscope-drying storage cabinets are preferable to conventional storage-only cabinets.
• Conducting risk assessments to determine the maximum safe storage duration

AORN

The Association of Perioperative Registered Nurses (AORN) 2022 guidelines align with ANSI/AAMI ST91. They advise drying channels for at least 10 minutes with instrument air or HEPA-filtered air. AORN also guides transport and storage protocols⁴.

SNGA

The Society of Gastroenterology Nurses and Associates (SGNA) 2018 standards recommend active drying of all endoscope channels and storage in an enclosed, clean cabinet. SGNA advises facilities to determine maximum storage times via risk assessment⁵.

EN16442

A European standard followed by many countries outside the U.S., EN 16442 specifies performance requirements for storage cabinets designed to store and, if necessary, dry endoscopes following reprocessing⁶.

How Do You Dry an Endoscope?

Properly drying endoscopes is essential to preventing bacterial growth from residual moisture. Manual and automated drying are the two most common options.

Manual Drying

Manual endoscope drying involves meticulously wiping exterior surfaces and flushing filtered air through each internal channel. Annex K in ST91 provides guidance for technicians to use forced air flow, rather than syringes, for channel drying³.

Automated Drying

Unlike labor-intensive manual methods, automated drying actively facilitates moisture removal from hard-to-reach internal crevices by sustained air circulation. A study in the American Journal of Infection Control reported that automated endoscope drying cabinets shortened external surface drying from 24 hours to three hours and internal channel drying from more than 24 hours to just one hour⁷.

Alcohol Flushing

While some guidelines, including SGNA, recommend it, other research indicates that alcohol flushing does not provide any drying benefits and can even introduce new reprocessing challenges⁵.

Alcohol fixation, for example, can exacerbate soil adhesion to surfaces, making thorough cleaning more difficult⁸. Concentrated alcohol solutions also pose health hazards to staff members⁹. Furthermore, a study published in the American Journal of Infection Control found that alcohol increased the drying time in some cases¹¹.

Research by STERIS Senior Scientist Michelle Nerandzic aimed to determine the efficacy of alcohol flushing for drying endoscopes and preventing microbial growth during storage¹⁰.

The study compared 70%-30% alcohol-flushed channels to those flushed with water alone. Results showed that all alcohol concentrations prevented bacterial growth, but surprisingly, 70% alcohol significantly increased drying time. The study also found that forced air drying effectively prevented bacterial growth, even without alcohol. Flushing with lower alcohol concentrations could aid in microbe control and provide faster drying.

Read the full article here: https://pubmed.ncbi.nlm.nih.gov/36130627/

How Long Does It Take to Dry an Endoscope?

No matter the drying method used, establishing sufficient drying time is challenging since most facilities lack methods to verify channel dryness. Although some guidelines suggest a drying time of at least 10 minutes, the actual process often extends from 90 minutes to several hours, varying based on the complexity of the device.^{12, 13}

Because it's not known when an endoscope is completely dry, using a continuous airflow solution provides the greatest assurance of minimizing residual moisture. Endoscope drying and storage cabinets, such as the ENDODRY™ Drying and Storage System and the Reliance™ 6500 Endoscope Drying and Storage Cabinets, provide this continuous airflow around the devices and even through endoscope channels.

What is an Endoscope Drying and Storage Cabinet?

Endoscope storage cabinets come in vertical or horizontal configurations, which have advantages depending on workflow needs. Unlike a standard storage cabinet, they are specifically designed to store, track, secure, and facilitate drying flexible endoscopes.

Vertical Endoscope Storage Cabinets Benefits

• Sliding panels with removable pegs that allow easy access to endoscopes and flexible storage for different types
• Dedicated drip tray for easy cleaning
• Visibility and access to multiple endoscopes at once
• Designed for high-volume facilities

Horizontal Endoscope Storage Cabinets Benefits

• Endoscopes are secure from swinging and contact with other surfaces that could lead to damage.
• Smaller overall height contributes to space savings
• Smaller footprint to save valuable floor space

Types of Air Filtration in Endoscope Cabinets

Regardless of endoscope cabinet orientation, proper air filtration is required to maintain a clean environment and protect endoscopes during storage. Facilities have two options when selecting systems:

• Instrument Grade Air represents a higher filtration standard, meeting strict criteria (ANSI /ISA–7.0.0–1996) to ensure optimal air quality within the cabinet environment¹⁵.
• HEPA-filtered Air is designed to remove 99.97% of particulates from the air, contributing to a clean storage environment¹⁶.

Endoscope Drying Storage Cabinet Comparison

	ENDODRY™ Endoscope Drying & Storage Cabinet	RELIANCE™ 6500 Endoscope Drying & Storage Cabinet
Storage Format	Horizontal, in Cassettes	Vertical Uses sliding scope hanging system
Air Type	A continuous flow of instrument grade air	A continuous flow of HEPA-Filtered Air that removes 99.7% of particulates
Capacity Options	Eight endoscopes	12 or 20 endoscopes, with add-on cabinets available of 12 or 20 more.

How Long Can an Endoscope Be Stored? (Hang Time)

After drying, endoscopes should be promptly and securely stored to prevent recontamination. The amount of time a disinfected/sterilized endoscope can safely remain in storage, often called "hang time," remains an open debate lacking consensus.

Professional guidance varies widely - from 7 days to 12 weeks - based on reprocessing and storage protocol stringency¹⁴. With unclear authority directives, facilities must conduct internal risk assessments, weighing factors like device complexity, drying effectiveness, and endoscope storage cabinet type to develop a policy on hang time.

How do you Transport an Endoscope?

After proper drying and storage procedures, facilities should also consider using dedicated endoscope transport containers.

The Society of Gastroenterology Nurses and Associates (SGNA) states, "Transport the soiled endoscope to the reprocessing area in a closed, puncture-resistant container that prevents exposing staff, patients, or the environment to potentially infectious organisms…"

Endoscope transport carts, such as the CLEANASCOPE™ ADVANTAGE system, minimize handling and maintain separation between contaminated and disinfected endoscopes while providing secure, protective storage to and from the procedure room.

Endoscope Drying and Reliable Storage

Amid mounting concerns over endoscope reprocessing efficacy, organizations now advocate for more stringent and standardized protocols for drying, storing, and transporting endoscopes to safeguard patient well-being. By investing in quality equipment and staff training on guidelines-based processes, healthcare facilities can optimize endoscope workflows, protecting patients from infections.

Explore STERIS Endoscope Drying & Storage Cabinets Here

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