AAMI News February 2018

Standards Spotlight: Endoscope Reprocessing Working Group Strives toward Stronger Guidelines

Mary Ann Drosnock
Mary Ann Drosnock is manager of clinical education for endoscopy at Healthmark Industries in Fraser, MI, and co-chair of AAMI ST/WG 84, the working group responsible for ANSI/AAMI ST91:2015.

Since its release in 2015, the standard ANSI/AAMI ST91, Flexible and semi-rigid endoscope processing in health care facilities, has brought much needed attention to best practices in endoscope processing, as well as leveled the playing field in terms of standard of care for processing scopes. However, as errors in endoscope processing and reports of infections related to endoscopy continue to occur, we cannot lose sight of the importance of following standards and applying the most stringent guidelines and quality steps to the processing of scopes.

Since the release of the standard, several key studies have been performed, new professional recommendations have been issued, and an overall change in the mindset to a quality approach has occurred. Because of these factors, and the fact that ST91 serves as a comprehensive guide for endoscope processing, the AAMI’s sterilization working group 84 (ST/WG 84) saw a need to update the standard to reflect these changes. As a result, the process of revising ST91 has been underway since 2016.

During our meetings, several important themes have arisen repeatedly—namely the need for stringent and verified manual cleaning of flexible endoscopes and the importance of drying completely prior to storage.

Cleaning Verification

Meticulous attention needs to be paid to all steps in the processing of flexible endoscopes and accessories to ensure that they are rendered safe for subsequent patient use. However, manual cleaning is such a critical step in processing endoscopes that it cannot be abbreviated. This point was underscored because any soil remaining may interfere with the ability of the disinfection, or even sterilization process, to effectively kill or inactivate microorganisms.

Cleaning verification tests are performed following manual cleaning to verify the effectiveness of a cleaning process and should also include a visual inspection. Performing cleaning monitoring tests is an important step in processing, as is the verification that manual cleaning was achieved as specified.

Although ST91 already includes recommendations for instituting cleaning verification testing, ST/WG 84 continues to stress the critical importance of this step. According to ST91, a facility’s quality assurance program should include ways to verify the efficacy of manual cleaning steps, and the verification process should be tested on a regular basis—at least weekly but preferably daily.


Drying remains an important topic and one that is evolving quickly through research and product development, such as drying cabinets and pumps. Effective drying after disinfection is known to reduce the risk of microbial contamination after high-level disinfection. ST91:2015 states that drying can be achieved by flowing compressed air through the endoscope channels, but the working group felt that this topic needs to be clarified and emphasized.  Additional guidance also is needed, as substantial confusion currently exists among healthcare facilities regarding how to accomplish a complete drying step.

The Road Ahead

An interim meeting took place in early January to continue working through the comments received and to develop a roadmap for the future of endoscope processing. The members of ST/WG 84 encourage you to stay tuned and get involved. For more information, contact standards@aami.org.

This article was excerpted from a column originally published in the January/February issue of BI&T, www.aami.org/bit.

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