By Rona Gazaway, MD, and Raleigh White, CRA, RT(R), MA
Given the widespread and expanding use of ultrasound, it’s imperative that institutions continuously review standard procedures to ensure consistency with current global guidelines for use with ultrasound transducers. Unfortunately, hospital settings provide an ideal environment for the transmission of health care–associated infections among patients and staff, thus making infection prevention a challenge. While ultrasound-guided invasive procedures represent significant risk of infection, endocavity ultrasound procedures are also associated with adverse outcomes. Of particular concern is risk of contracting the human papilloma virus (HPV), which can cause cervical and anogenital cancers.1
As many invasive procedures, eg, line placements and biopsies, are now being performed under ultrasound guidance, sterile gel must be used and appropriately reprocessed ultrasound probes must be implemented. In addition, emergency medicine practice—a busy environment with rapid patient turnover and possible congestion—is seeing an increase in ultrasound use. Unfortunately, despite infection prevention best practices, clinically significant organisms, including methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumonia, spread throughout health care facilities from contact.2
Global guidelines recommend high-level disinfection (HLD) between patient encounters for ultrasound probes used in semicritical procedures, including intracavity exams and for surface ultrasound procedures on nonintact skin, to effectively reduce the risk of infection for both patients and staff. Yet, consistent adherence to HLD best practices is not always implemented on ultrasound procedures. In fact, a 2018 survey published in the American Journal of Infection Control revealed that there are large number of procedures where HLD is not performed between patients, which is alarming, as there is a link to increased infection risk, outbreaks, and death associated with improper infection prevention.
2016: A Pivotal Year
At Hutchinson Regional Healthcare System (HRHS), where we serve the needs of more than 65,000 residents covering southcentral Kansas, we made the decision in 2016 to take a serious look at our hospitalwide infection prevention procedures. For medical imaging, particularly, we traditionally used soaking practices to disinfect our transducers. However, these practices varied, even among staff within the imaging department. The efficacy of this process presented a core challenge, as it must kill bacteria, viruses, and fungi that were threatening to cross-contaminate our patients on a daily basis.
We employed the help of our certified infection control practitioner, whose sole focus and responsibility is to coordinate and monitor our comprehensive efforts to keep preventable infections from occurring. When compared with national benchmark data, our infection rates are consistently at or below the published infection rates. Our infection control practitioner was eager to assist in a refined effort to elevate HRHS’ high standards and help us identify the most current research that could impact our patient population.
Of alarming concern was the looming threat of HPV, which was being discussed more prominently at medical conferences. Research has shown that HPV can be prevalent on transducers after endovaginal exams and can resist disinfection by manual soaking. In 2014, Meyers and colleagues were able to demonstrate that glutaraldehyde (GTA) and ortho-phthalaldehyde (OPA), two commonly used disinfectants, were unable to eradicate infectious HPV in a 45-minute liquid suspension test, including the HPV 16 strain responsible for up to 60% of all HPV-associated cancers. These findings first appeared in the Journal of Antimicrobial Chemotherapy.1
The fact that GTA and OPA were shown to be completely ineffective against HPV was distressing. Little was known at the time about HPV’s susceptibility to disinfection; yet a lot was documented about it being among the most common sexually transmitted diseases in humans. This study was a game changer, as it revealed that HPV could be spread through nonsexual transmission, and it prompted our department into action. We realized that common disinfection methods, even HLD methods, provided insufficient protection against the cancer-causing HPV on ultrasound transducers.
The alarming reality sank in fast, and we deemed it necessary to immediately perform a full evaluation of clinical disinfectants and disinfection standards related to transducer reprocessing within our ultrasound imaging department. We implemented big changes that year, and we’ve continued to evaluate and assess our best practices every six months.
We learned about HLD with sonically activated hydrogen peroxide, a method that did not require soaking or the use of chemicals and was proven to kill high-risk cancer-causing HPV. In particular, two studies caught our attention. One, conducted in 2014, tested hospital disinfectants against real, native HPV. It concluded that ethanol, isopropanol, GTA, OPA, and other disinfectants did not kill HPV 16 on endocavity transducers.1 The second study, published in 2016, found that surface carrier tests using the trophon HLD system with sonically activated hydrogen peroxide was shown to kill HPV 16 and HPV 18.3
We collectively agreed to adopt this technology for our institution and installed the unit in our imaging services department, where we required that it be used for all ultrasound exams. The implementation was not difficult and the learning curve was short.
Fast-Forward to 2018
In preparation for an upcoming survey by The Joint Commission, we conducted a departmental disinfection process assessment in 2018, which led to a broader hospitalwide evaluation. We included the operating rooms, emergency department, infusion center, and IR. Because we had expanded the assessment to a hospitalwide evaluation, we contacted Nanosonics Inc, the manufacturer of trophon technology, to perform a formal review of our infection prevention best practices within our health care system.
By now, we had additional HLD units in our department. The resulting report advised that we disperse infection prevention systems throughout the hospital to better help technologists, sonographers, and all clinical professionals comply with the latest standards and guidelines for reprocessing of both surface and endocavity transducers. Administration approved the expanded placement of our HLD units.
The Joint Commission survey took place in November 2018. We were confident in the reprocessing procedures we had in place, but the survey is never a stress-free evaluation. The surveyor was complimentary of the initiative we took by investing in proven HLD technology and found our HLD processes exemplary. The resulting report had no findings specific to ultrasound throughout the facility.
It is our honor to maintain the utmost in patient and user safety at HRHS by reducing the risks of cross-contamination between patients and reducing the spread of health care–associated infections. We have reduced the time to clean and disinfect transducers by approximately 85%. It takes 10 minutes from disinfection to storage. This time savings is substantial when you multiply it by the 2,040 probe cleanings performed at HRHS on an annual basis. It frees up valuable time for staff and provides opportunities for more face-to-face time with patients. The result has also been improved efficiency of workflow.
Of equal importance is our ability to now automatically capture information required for our staff to create audit-ready digital disinfection records for each exam. This has also helped our overall documentation efficiency while meeting regulatory compliance. Prior to implementing the automated HLD process, we were writing everything down in log books. The process was arduous, and there was significant room for error.
Lastly, we are proud of our reduced environmental footprint, due to our new best practices specific to ultrasound transducer disinfection. The HLD process generates water and oxygen—byproducts that are easily disposed of. We have eliminated all toxic chemicals, and we’re able to pour excess water down the drain and recycle upwards of 70% of the components in the units.
— Rona Gazaway, MD, is the imaging medical director of Hutchinson Regional Healthcare System in Hutchinson, Kansas.
— Raleigh White, CRA, RT(R), MA, is the director of imaging services for Hutchinson Regional Healthcare System. He will present a poster on the steps and challenges involved in the successful rollout of a standardized ultrasound probe reprocessing policy across his facility at the 2019 Summit on Quality on May 10 in Wichita, Kansas.
1. Meyers J, Ryndock E, Conway MJ, Meyers C, Robison R. Susceptibility of high-risk human papillomavirus type 16 to clinical disinfectants. J Antimicrob Chemother. 2014;69(6):1546-1550.
2. Hoyer R, Adhikari S, Amini R. Ultrasound transducer disinfection in emergency medicine practice. Antimicrob Resist Infect Control. 2016;5:12.3. Ryndock E, Robison R, Meyers C. Susceptibility of HPV 16 and 18 to high level disinfectants indicated for semi-critical ultrasound probes. J Med Virol. 2016;88(6):1076-1080.