Ultrasound Transducer Disinfection: “Circular Knot of Interrelated Jurisdictions and Regulations”

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The requirements of which cleaning procedure required to disinfect ultrasound transducers varies widely from one regulatory body to another. To attempt to simply the strategies, The American Institute of Ultrasound in Medicine (AIUM) introduced "Disinfection of Ultrasound Transducers Used for Percutaneous Procedures: The Intersocietal Position Statement" on February 19, 2021. However, since the Joint Commission has the final authority on what facilities enforce, it is confusing because FDA and CDC interpret the Spaulding Classification System differently.

Oliver D. Kripfgans, PhD, FAIUM, is a research associate professor of radiology, biomedical engineering, and applied physics at the University of Michigan, discusses this intricate and important situation.In this fourth and final installment of his interview with Infection Control Today^® (ICT^®), Kripfgans examines what the controversy of which disinfection procedure to use and which contributors need to eliminate the problem. 

First installment is here. Second installment is here. Third installment is here

Infection Control Today^® (ICT^®): Given the contradictory views in circulation, what should infection preventionists and infection control professionals do? What do we tell these clinicians about how to disinfect ultrasound equipment used in percutaneous procedures?

Oliver D. Kripfgans, PhD, FAIUM: Ultimately, it is the Joint Commission that has enforcement authority over the policies and procedures that apply to health care practitioners.So when the Joint Commission insists that practitioners must follow manufacturer instructions for use, it is natural that those practitioners would make every effort to comply.

However, it is not automatic that manufacturer instructions for use will require high-level disinfection (HLD) for transducers used in percutaneous procedures. We know of several manufacturers that have issued letters permitting the use of low-level disinfection (LLD) or intermediate-level disinfection (ILD) for their equipment, and the Joint Commission has indicated that it will accept such policy changes when issued by a manufacturer. In such cases, clinicians whose facilities use equipment from more than 1 manufacturer could be faced with an interesting choice. They might decide to use only 1 manufacturer’s equipment in percutaneous procedures, simply because that manufacturer’s instructions for use permit disinfection via LLD or ILD.

The entire issue is a somewhat circular knot of interrelated jurisdictions and regulations. The Joint Commission points to FDA regulations requiring health care professionals to follow all manufacturer instructions for use. FDA points to the manufacturer’s responsibility to validate its instructions for use, typically through the evidence produced in clinical studies. Some manufacturers may issue permission to use LLD or ILD on their equipment (with or without validating evidence), but the bulk of manufacturers have not invested their time or money in clinical studies, choosing instead to reduce their liability by requiring HLD as an “extra margin” of safety, and pointing to FDA regulations as the reason they cannot permit LLD or ILD. FDA points to its reliance on CDC’s interpretations of the Spaulding Classification System in its various guidelines. And CDC—as we’ve just discussed—needs to be convinced to revisit its guidance documents. In effect, everyone is waiting for someone else to make the first move.

With publication of the Intersocietal Position Statement, the taskforce is trying to undo this knot—starting with an assessment of the peer-reviewed literature related to cleaning and disinfection of transducers used in percutaneous procedures. There is evidence in the literature for the effectiveness of cleaning and ILD, with no increased risk of infection. Correspondingly, there is no evidence of problems with infections being spread as a result of disinfection performed at an improper level.

It would not be a bad idea for more clinicians to explain to their manufacturers the dilemma they face in everyday practice. Without any justification, practitioners are being asked to spend time and apply resources that they do not have in abundance, putting them in the position where they might choose not to use ultrasound to guide line placements or perform peripheral access procedures. Manufacturers are naturally defensive of their market, so the possibility that some practitioners might stop using ultrasound could provide motivation for manufacturers to revisit their instructions for use.

Unfortunately, the controversy surrounding this issue has created an environment that is not exactly conducive to discussions between practitioners and their suppliers. Many sonographers have expressed their fear that they would be in both legal and professional jeopardy if they cleaned a transducer inadequately, resulting in a patient acquiring an infection. Because they expected that all of the responsibility would fall to them—not to the radiologist or other physician who ordered the procedure—it is easy to understand why these sonographers were so afraid. And from there, it was very easy to convince them that their best course of action would be to perform HLD, even though doing so would not be a prudent use of their facility’s resources.

A number of forces may play a role in changing the current environment of policies and practices related to the disinfection of ultrasound equipment. Regulatory agencies—Centers of Disease Control and Prevention (CDC), Environmental Protection Agency (EPA), Food and Drug Administration (FDA), and the Joint Commission—may drive the lion’s share of changes through coordinated revisions in their guidance documents. But the inclination of manufacturers to protect their market—and to capture market share from other companies—could also play a role in stimulating revised instructions for use. Some manufacturers may also be swayed by the logic and evidence found in peer-reviewed literature, making them more willing to adapt to a landscape of revised policies and practices.

Publications such as ICT^® can also contribute to changing the current environment by providing unbiased information and encouraging critical thinking among their readers. It is important that professionals are aware of the differences between guidelines based on verified evidence and those driven by commercial interests or propelled by fear.

In the end, practitioners need guidelines that are driven by logic and evidence, so that they can perform the appropriate level of disinfection for a given procedure. We’ll know we’re there when practitioners are able to consistently prevent the transmission of infections without unduly burdening the resources of their facilities or the health care system as a whole.

ICT: What additional advice would you offer to practitioners who are trying to navigate the complexities of current practice guidelines on cleaning and disinfection?

OK: Practitioners should make sure that they and their colleagues are fully educated about all of the guidelines relevant to their procedures. In daily practice, clinicians should follow those guidelines as instructed by the Joint Commission.

But the use of such guidelines should not be performed uncritically. Practitioners should always be critical of policies and guidelines intended to direct their practices and procedures, and they should never be afraid to reach out to their professional associations with questions. In the case of the Intersocietal Position Statement, practitioners can direct their questions to AIUM or any of the statement’s signatory organizations.

The same approach applies to those who are attending conference sessions or webinars. Even if they need to overcome their discomfort about asking questions in public, attendees should never miss the opportunity to ask questions that will clarify the information being presented. Getting clear answers about recommended practices and procedures can help to position practitioners to perform those procedures competently and prudently according to their level of involvement.