Are disposable electrodes a solution to preventing cross-contamination?

Sleep technologists might not think twice about cleaning their patients’ skin to hook them up to electrodes that monitor brain waves during an electroencephalogram (EEG). It’s a process that may break the skin, but there is usually no harm done if the equipment is sterile. The problem is that many reusable electrodes, deemed clean and ready for the next patient, could still harbor harmful pathogens, and sleep techs could be unknowingly putting their patients at risk of infection, new research shows.

Microscopic traces of human tissues and bacteria have been identified on reusable EEG electrodes after they have been cleaned. A study published in the American Journal of Infection Control in December showed that 25% of cleaned reusable electrodes still had bacteria present. Of the 8 bacterial species identified, 7 were a potential risk for causing human infection, according to the study.1

“Even when we follow all aspects of high-level disinfecting for our reusable products, there are so many nooks and crannies on the electrodes that there is no way to ensure that an electrode is completely free of any risk of contamination,” says Leah Hanson, R.EEG/EP T, vice president of global sales and marketing at Rhythmlink International, a medical equipment manufacturer based in South Carolina.

This issue is further exacerbated because EEG sets typically include multiple lead wires and cup electrodes that may become entangled, making them more difficult to clean, the study says.

Policies for keeping these sets sterile are not always standardized in hospitals and not always followed closely, says Tomas Diaz, MD, clinical specialist for Advantage Medical Cables, a medical technology company.

“Every hospital and clinic is unique, with individual needs and clinical situations….There is no standard method for cleaning reusable EEG electrodes. Manufacturers may or may not give recommendations, but hospital/clinic EEG labs will likely have their own protocol for cleaning to be used in conjunction with other guidelines (OSHA, CDC, FDA, and EPA),” says Mary Ellen Wells, PhD, RPSGT, R. EEG T., R. NCS T., director and associate professor, Neurodiagnostics and Sleep Science at The University of North Carolina at Chapel Hill.

The four hospitals that participated in this latest study followed varying cleaning regimes that involved soaking the electrodes in a dishwashing detergent or a germicidal bleach cleaner and wiping or spraying the devices with bleach.

According to the ASET – The Neurodiagnostic Society, commercial chemical disinfectants or bleach can be used to clean reusable electrodes. The organization warns that techs should use caution to not over-dilute the bleach with water when soaking electrodes, or else the cleaning process may be not as effective. Bleach also has a relatively short shelf life. Only four weeks after a bottle of bleach is uncapped, the solution starts to lose strength.2

During the study, the researchers collected 30 swab samples from electrode sets at the hospitals, located throughout the US, over a 10-week period. Overall, the study found that 31 of 124 electrodes had a positive bacterial culture. Human cells were found on 60.5% of electrodes.

After the results of this study were released, some sleep labs decided to make the switch to disposables. Soon after the new research surfaced, Boston Children’s Hospital’s Department of Neurology transitioned to one-use EEG electrodes, says director of technical operations Jack Connolly, BSIT, R. EEG T.

Prior to the switch, the techs at Boston Children’s used a similar procedure to the cleaning methods described in the study. The procedure was to wash with dishwashing soap and water and scrub gently with a brush. Then they would use a bleach-based disinfectant wipe, let the electrodes sit for 2 minutes, and then rinse with water.

“I think the cleaning methods are likely sufficient, as that is what we have used for over 30 years and I have never heard of a case of infection. That being said, we decided to switch ourselves out of an abundance of caution,” says Connolly.

This new data sheds light on how disposable products could provide a solution to lower patient risk of infection, says Brett Alpaugh, senior market manager for Ambu, a Danish medical technology company focused on providing disposable solutions to hospitals. Ambu provided funding for this latest study.

Another way to prevent cross-contamination is to establish and standardize an effective cleaning method and then educate the techs who work with these devices, says Diaz.

According to Alpaugh, health workers don’t typically think of electrodes as risky technology. “A lot of these cup electrodes are not being cleaned properly,” he says. “Once you have abraded skin, this really falls into the same category as scopes that go down your throat and enter inside your body, they have to be cleaned the same way.”

Another study published in August in the journal PharmacoEconomics found that the rate of sepsis due to electroencephalography procedures was an estimated 33 cases per 100,000.3

As the pool of research showing the risk of cross-contamination grows, awareness is rising among medical professionals and a transition to disposable electrodes has begun, Hanson says.

She estimates that about 50% of clinics and hospitals have started using disposable electrodes or are in the process of making the switch. “We are being forced, like it or not, in our industry to have to move to disposables,” she says.

Ambu has also seen an increase in sales of disposable electrodes, currently selling these products to about 500 facilities. “We’ve seen significant growth in our cup electrode business over the last five years, as we’ve seen hospitals paying more attention to the risk associated with reusable products,” says Alpaugh.

There seems to be a general shift in hospitals toward disposable products to mitigate the spread of germs between patients. SLP (Scientific Laboratory Products) , a developer and manufacturer of sensors for diagnosing sleep disorders, has seen a spike in sales of its disposable SleepSense sensors, according to a statement from the company.

For decades many sleep techs believed there was little risk of cross-contamination when using these devices, but mounting data now shows that the likelihood of contamination is relatively high, says Hanson, who also worked for several years as a sleep tech.

While the upfront cost of deposable electrodes is typically greater than reusable ones, hospitals will end up saving money in the long run by decreasing liability and cutting back on the time that it would normally take to clean them, says Alpaugh.

Some think that using disposable devices is just a quick, temporary solution and that medical facilities will ultimately have to figure out a way to keep their reusable electrodes pathogen-free because the added expense of disposable equipment is just not sustainable. “We are adding cost to one already high cost of healthcare,” says Diaz. “I don’t think this is going to be the solution.”

Lisa Spear is associate editor of Sleep Review.

Updated 1/8/19 to include information from The University of North Carolina at Chapel Hill, ASET, and Boston’s Children’s Hospital.


1. Albert NM, Bena JF, Ciudad C, et al. Contamination of reusable electroencephalography electrodes: A multicenter study. Am J Infect Control. 2018 Dec;46(12):1360-4.

2. Scott NK. Infection Prevention: 2013 Review and Update for Neurodiagnostic Technologists. Neurodiagn J. 2013;53:271–88.

3. Sohrt A, Mærkedahl A, Padula WV. Cost-effectiveness analysis of single-use EEG cup electrodes compared with reusable EEG cup electrodes. Pharmacoecon Open. 2018 Aug 27.  [Epub ahead of print]