Low-Level Disinfection of Your Ultrasound Machine During the Pandemic: Which Wipe Should I Wipe With?

ACEP Ultrasound Safety Subcommittee

Currently the world is facing a pandemic due to the spread of the SARS-CoV-2 virus, the cause of COVID-19.¹ Emergency physicians are on the front line and are involved in many aspects of dealing with COVID-19 including direct patient care and emergency or disaster management. Specifically, our integration of Point-of-Care Ultrasound (POCUS) may be important in both the detection and resuscitation of patients who are critically ill.^2-4 As the direct care team, our utilization of POCUS not only improves our ability to diagnosis and guide treatment it also helps to reduce potential exposure of other members of our health care team.³

However, we must be diligent with infection control and the potential of our ultrasound probes and systems as a vector/fomite for cross contamination.⁴ This is a unique situation for many of us in that we are dealing with an emerging disease infection; policies and procedures have not been through many levels of testing over time.

While many professional organizations have recommendations of disinfection, the evidence for the efficacy of low-level disinfection (LLD) for SARS-CoV-2 remains limited.⁵ Current best practice comes from testing of LLD against similar human coronaviruses.⁶ Common LLD wipes and cleaners recommended for cleaning ultrasound probes are thought to be viricidal for enveloped viruses, like all coronaviruses.⁴ Unfortunately, there is no widely available data on the SARS-C0V-2.⁶

Recommendations for disinfectants to be used in dealing with SARS-CoV-2 are based on the Environmental Protection Agency's (EPA) List-N. The EPA states that these products are thought to be efficacious against the virus. To be part of List-N a product will have to meet one of three criteria.

1. Demonstrated efficacy against a harder to kill virus
2. Demonstrated efficacy against a similar virus
3. Qualified for emerging viral pathogen claim

For SARS-CoV-2, the EPA activated the Emerging Viral Pathogen Guidance for Antimicrobial Pesticides on January 29, 2020. This allows EPA registered manufacturers to voluntarily submit applications to be considered for use against the emerging pathogen. To qualify as a product used against an enveloped viral emerging pathogen, it must be approved by the EPA to inactivate at least one large or small non-enveloped virus.

Currently List-N products should show efficacy against non-enveloped viruses to be considered efficacious against SARS-CoV-2 under the emerging viral pathogen process. However, this process is voluntary and not all product manufacturers file the application for their entire line of products that could meet the requirement.⁷ The products on List-N should be cross-referenced against the products that are approved for use by the ultrasound manufacturer to avoid damage to your system and probes.

The ACEP Emergency Ultrasound Section has published a policy statement for guidance on the process of preparing and cleaning your ultrasound system in relation to COVID-19 patients.⁸

Below are links to documents referenced in the article and List-N which are updated by the EPA as new products meet the requirement to be listed.

EPA Links

• EPA List N: Disinfectants for Use Against SARS-CoV-2
• EPA Emerging Viral Pathogen Program Guidance
• EPA activation of Emerging Viral Pathogen Guidance for Antimicrobial Pesticides

Manufacturer Links to Cleaning Guides

• Zonare
• Mindray
• Fujifilm Sonosite
• Philips
• GE Healthcare
• Canon Medical
• Siemens
• Samsung
• Butterfly IQ
• Clarius

References

1. WHO Coronavirus (COVID-19). 2020. at https://covid19.who.int/
2. Sikachi R, Agrawal A. Whole body point-care ultrasound for COVID-19: a multi-system approach to a multi-system disease. Anaesthesia. 2020.
3. Buonsenso D, Pata D, Chiaretti A. COVID-19 outbreak: less stethoscope, more ultrasound. Lancet Respir Med. 2020:S2213-600(20)30120-X.
4. Kim DJ, Jelic T, Woo MY, et al. Just the Facts: Recommendations on point-of-care ultrasound use and machine infection control during the coronavirus disease 2019 pandemic. CJEM. 2020:1-5.
5. Abramowicz JS, Basseal JM. World Federation for Ultrasound in Medicine and Biology Position Statement: How to Perform a Safe Ultrasound Examination and Clean Equipment in the Context of COVID-19. Ultrasound Med Biol. 2020:S0301-5629(20)30149-6.
6. How does EPA know that the products on List N work on SARS-CoV-2? 2020. at https://www.epa.gov/coronavirus/how-does-epa-know-products-list-n-work-sars-cov-2.)
7. Emerging Viral Pathogen Guidance for Antimicrobial Pesticides Registration. 2020. at https://www.epa.gov/pesticide-registration/emerging-viral-pathogen-guidance-antimicrobial-pesticides
8. ACEP COVID-19 Field Guide: Ultrasound Cleaning. 2020. at https://www.acep.org/corona/covid-19-field-guide/work-safety/ultrasound-cleaning/

Arun Nagdev, MD
Ultrasound Director at Highland General Hospital
@NagdevArun

Jason T. Nomura, MD, FACEP
Ultrasound Director at Christiana Care Health Services
@Takeokun