Contamination of Point-of-Care Ultrasound Transducers Alarms Key Clinician

Ultrasound transducer with barrier dressing (Image courtesy PICC Excellence, Hartwell, GA).

Inconsistency in ultrasound transducers leads to health care-associated infections (HAIs), and many HAIs are because the health care workers are not following strict protocol of using probes that are covered, proper thorough disinfection of surfaces, and using demonstrated safe decontamination procedures.

Infection Control Today^® (ICT^®) spoke with Nancy Moureau, RN, PhD, CRNI, CPUI, VA-BC, expert in the field of vascular access practice, owner and CEO of PICC Excellence, and a member of ICT^®’s editorial board about concerns of contamination and what can—and does—happen when the proper procedures are not followed. Finally, Moureau covers what it means when a health care worker says he or she does not have time to do proper hand hygiene.

This is the first of a 4-part series.

Infection Control Today^® (ICT^®): What are the principal contamination concerns associated with transducers used in point-of-care ultrasound procedures?

NM: Basically, our concerns associated with ultrasound and the types of transducers used for percutaneous procedures go along the lines of blood exposure and exposure to other types of bacteria that can be transmitted from patient to patient. We have contamination concerns when naked probes or naked transducers are used, and there’s no disinfection of the surfaces before and after, which is the standard recommendation.

Contamination of transducers occurs through skin contact, through contact with unsterile or contaminated gloves, or through contact with hands that are not covered by gloves. We also have environmental contaminants where the transducer may be sitting in the air and have contaminants that attach to the surface. There are a number of contamination concerns associated with transducers that require us to have very consistent use of disinfection before and after a procedure.

ICT^®: Those procedures are required, and if they’re not performed correctly, health care-associated infections (HAIs) and other situations can arise.

NM: Hand hygiene is required too, but we all know that there is great variability and inconsistency in the way hand hygiene is practiced. If blood is detected on a transducer after an ultrasound procedure, someone didn’t do something they were supposed to do. Unfortunately, that’s truly not uncommon.

A problem associated with ultrasound use in emergency departments or intensive care units is that ultrasound units are used for a variety of applications. Some of those applications may be more invasive than others, involving the use of a probe rather than a transducer. In the field of vascular access, which is my primary focus, we are lucky to use only linear transducers that do not contact mucus membranes and do not enter the body. In that situation, the types of contaminants capable of attaching to the transducer are limited, but risk is certainly still present.

ICT^®: You mentioned inconsistency in hand hygiene, but there’s also inconsistency in the use of supplies, including transducer barriers and covers. What do you think that inconsistency suggests about the safety of point-of-care ultrasound procedures?

NM: When I see inconsistency, it suggests that there is a lack of standardization, and limited education and training in the protocols and procedures demonstrated to be safe in clinical practice.

My comments mostly apply to ultrasound-guided peripheral IV access or the use of ultrasound for central lines. We know that bloodstream infections can occur if the contaminants attach to the catheter or are pushed into the bloodstream. There’s certainly a higher level of risk associated with the placement of ultrasound-guided peripheral venous catheters when there are inconsistent practices of using nonsterile gel, not cleaning the transducer, or not protecting the transducer.

Clinicians often use the term “transducer” and “probe” interchangeably, but they are not equivalent. “Probe” refers to an ultrasound device that enters the body or is used in contact with mucus membranes, while “transducer” refers to a device used on intact skin or in guiding percutaneous procedures. However inaccurate, “probe” tends to be the most common term used for all.

Whichever device is in use, for whatever medical specialty and procedure, we see a huge amount of inconsistency from clinician to clinician, department to department, and site to site. The cause of such inconsistency often comes down to a lack of training.

ICT^®: One thing that has come up in all the interviews I’ve done with clinicians is their lack of time. Do you think that time pressures have anything to do with causing inconsistencies in practice?

NM: Oftentimes when people take the stance that they don’t have enough time, they’re saying that they don’t have enough time to provide a safe procedure for the patient.

In some cases, that’s true. When a patient comes in with a high trauma situation, the clinicians are just trying to save the patient’s life. There may not be time to grab a transducer cover or protective barrier. Nevertheless, the clinicians may use ultrasound to try to gain vascular access and administer lifesaving drugs in order to save the patient.

However, our job is to safeguard the patient and provide procedures using methods that are as safe as possible. So when we insert an intravenous device under less-than-sterile conditions, there should be policies that allow for tagging that device so that it can be removed and replaced as soon as possible, and for making sure that other clinicians are aware of what happened during the procedure.

Very often, I find that none of those things actually happen. The clinicians take care of what they can take care of, transfer the patient out of the emergency department (ED), and immediately go on to the next patient. Consequently, even patients in other departments may be put at risk. Meanwhile, the other departments are never made aware of the breaks in technique that were performed on the patient.

I believe in using a standardized procedure with materials and devices that are efficient, timesaving, and capable of being used in trauma situations or in a very high volume, high-speed ED or intensive care unit. Separating the transducer from the insertion device by using a barrier dressing can help to save time, while eliminating gel from the risk equation. A barrier dressing can enable a clinician to save time by using any kind of gel that is within easy reach, while still safeguarding the patient. Teaching everyone about these timesaving methods and devices is part of how we need to standardize care for safeguarding our patients.