This article provides some initial advice and commentary to medical staff considering purchase of the Trophon EPR Ultrasound Transducer High-Level Disinfection System (or, “Trophon EPR”). Some of this article’s guidance may be used, in part, to assess this device’s safety and effectiveness.

First, a YouTube video that demonstrates the clinical use of this device can be watched by clicking here.

Second, while it is a new product with a limited track record, the Trophon EPR is novel, interesting, and may add value to the fields and arsenals of instrument reprocessing and infection control. When performed correctly, automated reprocessing may have some advantages compared to manual reprocessing.

Dr. Muscarella has not worked with or encountered the Trophon EPR in the field, however, so, admittedly, his knowledge of its operation, safety, and effectiveness is limited.

Nevertheless, he offers a few recommendations, interesting comments and insightful questions about the Trophon EPR’s suitability and cost-effectiveness for processing ultrasound transducers:


Update: This is the second in a series of two articles that discuss the Trophon EPR. Click here to read Dr. Muscarella’s related article: “Relative Ineffectiveness of Certain High-Level Disinfectants for the Inactivation of Human Papillomavirus, or HPV.”


–1.–  The Trophon EPR was cleared by the FDA for the high-level disinfection of “ultrasound transducers” (in about 7 minutes).  So, first, consider clarifying with its manufacturer whether the Trophon EPR is cleared to disinfect all types of ultrasound transducers/probes (including transesophageal echocardiography, or TEE, probes; transrectal probes; and endovaginal probes) from all manufacturers including, for example, GE Healthcare (i.e., the apparent distributor of the Trophon EPR);

or, whether there are some types of transducers (which ones?) marketed by some companies (which ones?) that the Trophon EPR is not indicated to high-level disinfect.

This clarification is an important labeling consideration. (For the purpose of this response, I do not distinguish between an ultrasound “transducer” and an ultrasound “probe.”)

–2.– For those specific ultrasound transducers and probes that the Trophon EPR is labeled to high-level disinfect, consider requesting confirmation from their manufacturers’ quality assurance departments confirming that the Trophon EPR’s hydrogen peroxide-based disinfectant (at its indicated concentration of 31.5% and minimum chamber temperature of 56o C) and sealed chamber’s fluid pressure will not damage any of their probes’ or transducers’ components or materials.

The Trophon EPR’s stated compatibility with the materials and components of different ultrasound transducers is an important quality-assurance measure with implications that, in addition to its initial cost and cost per cycle, affect the Trophon EPR’s cost-effectiveness. (Click here for more details about the Trophon EPR’s compatibility.)

–3.– Understand that, if a facility were to purchase the Trophon EPR, its use would require that the cleaned probe be *dried* prior to high-level disinfection, not remain wet with rinse water prior to processing. Because the probe does not have any internal channels, this is unlikely to be a limitation.

The YouTube link, above, suggests that wiping the instrument with a paper towel before disinfection is sufficient (although, this practice could be controversial if such wiping were to re-contaminate the instrument). I would recommend wiping the instrument after disinfection only if doing so does not result in the instrument’s re-contamination (i.e., use a “sterile,” or at least new and clean, wipe).


Quality Reviews and Reports for Hospitals, Manufacturers, Patients:  Click here to read about Dr. Muscarella’s expertise and legal assessments of the causes of healthcare-associated infections, including “superbug” outbreaks linked to contaminated GI endoscopes and other reusable medical equipment.


–4.– The 510(k) clearance letter of the Trophon EPR, dated February 24, 2011, states that upon completion of this automated device’s cycle, the disinfected ultrasound transducer is “ready for immediate use.” Therefore, consider clarifying with its manufacturer whether any infection-control practices (e.g., drying the probe using 70% alcohol) might be required, or are permissible, if the probe were not to be used “immediately” after processing but, for example, several minutes later.

Namely, does the device’s instructions for use (IFUs) indicate the appropriateness of wiping the instrument with a paper towel to dry it after its reprocessing and prior to its use?

Click here to read about a different program developed by this blog’s author that provides advice to manufacturers to improve the quality and safety of their medical devices and infection-control products.

According to an obvious definition of “immediate,” any delay in its clinical use after processing might require (depending on the manufacturer’s labeling) that the probe be reprocessed, again, in the Trophon EPR before the probe’s reuse.

Moreover, as I have published, the use of a wet instrument in the clinical setting can increase the risk of disease transmission. Refer to one of my articles on this topic in the journal “Chest” by clicking here.

The definition of “immediate” is a possible source of confusion. Specifically, if the its definition were viewed pragmatically, a fair question to ask is the amount of time that would be allowed to elapse after the probe’s processing without violating the device’s definition of “immediate” (e.g., 0 seconds, 1 minute, 5 minutes, up to one hour).

A question is posed:  Would the use of a possibly wet ultrasound probe 10 minutes after its processing be considered, from a pragmatic standpoint, still “immediate” and consistent with the Trophon EPR’s labeling?

–5.– The Trophon EPR is a “disinfector,” not a “washer-disinfector,” and, therefore, this device requires staff to thoroughly perform cleaning (according to the probe’s labeling) prior to automated disinfection. Such manual cleaning is commonplace, however, and would not seem to be a significant limitation.

–6.– The Trophon EPR is indicated to high-level disinfect the probe, including its shaft and handle. Consider clarifying with the Trophon EPR’s manufacturer whether any other of the probe’s components (e.g., its cable?) require some reprocessing, and, if so, the level of decontamination.

–7.– And, because the Trophon EPR uses vaporized hydrogen peroxide, it appears that the ultrasound transducer – and this a somewhat unique and potentially beneficial feature – does not require water rinsing after exposure to the disinfectant, which presumably would reduce the likelihood of the use of a wet probe and the transmission of environmental, waterborne bacteria via the probe.

But wiping the probe with a paper towel after its processing could be a concern if the towel is not clean or is otherwise contaminated.

Nevertheless, the Trophon EPR’s brochure indicates that small quantities of water vapor (and oxygen) are produced as by-products of the process.

Therefore, water may remain on the instrument after its processing, thereby explaining why the Trophon EPR’s labeling requires “immediate” use of the processed probe (and why the YouTube shows the nurse wiping the wet probe to dry it after its processing).

Whether the amount of water (as a vapor) remaining on the processed probe is sufficiently significant for an infection-control guideline to recommend drying the probe (facilitated by the use of 70% alcohol) before its clinical use is unclear and something to be clarified. To be sure, wet instruments generally increase the risk of bacterial infections.

In closing, there are several issues (e.g., those with financial, infection-control, quality-assurance, and both safety and effectiveness implications) that require addressing before purchasing, and when using, any device used to reprocess an ultrasound probe, flexible endoscope, or other type of reusable instrument.

I am unaware of the Trophon EPR being associated with any instrument damage, faulty disinfection, inadequate water rinsing, or patient infection or harm. — Lawrence F Muscarella, PhD

Also, do not hesitate to contact the Trophon’s manufacturer with any additional questions. This manufacturer appears to be committed to quality and patient safety. [The End]


Article by: Lawrence F Muscarella, PhD; posted 9/4/2013; updated 6/11/2015, Rev A.

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