Pediatric leads

Expert Advice: Electrodes EEG Signals

We run a pediatric sleep lab and our leads can take quite a beating. What draw backs are there to the disposable leads vs reusable? Also what is the difference in using "cup" leads and flat leads?

Reusable EEG Electrodes and Disposable EEG Electrodes are more alike than they are different. Both electrode types typically use the same type of lead wire and connectors. The only difference is the “cup” itself.

A reusable EEG Cup is a reliable and accepted product for quality testing and disposables are still proving themselves regarding their quality of recording compared to a reusable. I would recommend doing a “head to head” comparison of reusable electrode versus disposable electrodes literally on the same patient. For instance, use reusables on the right and disposables on the left and compare directly. This is the most reliable way to compare quality of each lead type for your individual patient demographic and application style. This will answer the top priority question…does a disposable record as well as a reusable?

Now, advantages of reusables are they typically are made of 99.9% silver and coated with either silver/silver chloride or plated with gold. Because of the robust metal that is used the reusable EEG electrode can last months. My experience is reusable EEG electrodes last an average of 5 months…some longer and some shorter. The life of the product is most definitely the benefit of a reusable electrode. This benefit of long product life can also be a cost savings as well in certain situations.

Disposable cups may not have that advantage but they have their own benefits to offer. Regarding material of the disposable cup, the cup part is typically made of a plastic that is coated with a silver/silver chloride coating. They are designed to record equally as well as a reusable. They are not as durable as a reusable cup but they don’t need to be because they are designed for a single patient. But, they do not have a Gold option--only silver at this point. This can be a negative for some services who use Gold.

But, the ability to “reuse” an electrode can be the negative as well. There is no guarantee how long a reusable will last--it could break 30 days after being used and depending on your warranty this can be costly. Also, the reusable electrode requires strict compliance with cleaning and disinfecting protocols to ensure the electrode is safe for repeat use across multiple patients. If the skin of the patient is abraded, meaning if you use a Q-Tip, for example, with NuPrep or any other prep that is designed to lightly abrade the skin, that electrode falls under the criteria of a Semi-Critical item and requires specific disinfecting protocols. Most commercially available disinfecting solutions such as Cidex or others meet this criteria, but an electrode cannot be used without full compliance to the recommended cleaning directions of these products. And, this can lead to higher labor costs to clean and disinfect a reusable electrode. Even if you have staff spending 20 minutes to clean and disinfect reusable electrodes--this is money and cost for the department or service that MUST be considered when a cost comparison is being done between reusables and disposables.

The general impression is typically that reusables are less expensive than disposables. However, disposables have cost benefits even though many people do not look at the full investment to a service to appreciate the cost savings. For example, the direct cost of disposables versus reusables will no doubt show a cost savings to the reusable product. But, it’s not just the direct purchase cost that should be considered. Costs of additional inventory, chemicals for cleaning and disinfecting and as mentioned above the cost of labor, even what seems to be a small amount of labor, can add up quickly.

So, costs, historically, have leaned towards reusables, but now a service should run analysis and decide of that is true to for their situations. Quality can be comparable or identical, but again should be individually compared. Reusables offer a Gold option and Disposables currently do not. Disposables arguably offer the best risk management option due to elimination of cross contamination risks because they are not reused.

So, long answer for your question is there are pros and cons to both. And, both should be openly considered in your service. You may even find that your service can efficiently and cost effectively use a combination of both reusable and disposables which could be a definite benefit for a pediatric facility that can deal with many other risks of fluids, electrode contaminations, etc.

The second part of your question about the cup design versus the flat electrode design. The “cup” itself is designed to hold the conductive paste--a storage spot basically. The problem with the cup design is that our paste begins to melt or dissipate away as soon as we put the lead on the patient due to the patient’s body heat. When the paste begins to “melt” out of the cup, the surface area of the cup no longer has consistent contact with the conductive material and this will lead to pops and other artifact issues as the testing goes on.

Flat electrodes whether disposable self adhesive stickies or reusable flat electrodes can better retain the consistency of the conductive material in contact with the electrode. So, the flat lead should allow for more consistent recording quality for a longer periods of time. But, again, this should be tested per facility to compare the options. Some flat electrodes take some time to “get used to” and may require slight adjustments in application techniques. Additionally, some flat electrodes are significantly more comfortable for the patient and have shown to cause less skin irritations than some cup designs.

Cup designed electrodes can be maximized for their potential with a good covering placed over the cup to help keep the paste in place longer; but the flat designs offer patient comfort and some skin benefits as well. And especially with pediatrics the comfort and skin integrity issue is probably more prominent than in an adult facility.