Ultrasound Cover: How to install it?

At EDM Medical Solutions, we're all about infection control. In this article, we will review the good practices when putting on a sterile ultrasound cover. General purpose covers are required when performing ultrasound-guided procedures. They include regional anesthesia, catheter placement, core tissue biopsies (breast, liver kidney) or other radiology interventions (drainages, aspirations). Of course, these operations are done in a sterile environment. Hence, the need for a sterile cover is obvious, but the setup protocol needed to protect the sterile barrier may not be that obvious.

Two techniques are generally admitted to cover your ultrasound transducer adequately:

• The single-person method
• The two-person method

Let's review each one of them.

Setting up the ultrasound cover using the single-person technique

What is it?

A single-person technique is when only one operator is in charge of putting on the ultrasound cover. He/She is in a sterile environment, with sterile gear: mask, gown, gloves. Of course, the caregiver cannot touch non-sterile objects or surfaces as it will break the sterile field.

So how to apply a probe cover when you're on your own and have to deal with sterile and non-sterile materials in your environment? Let's find out!

How to do it?

To start with, you want to make sure that the following steps are easily reproducible. Now the first thing to do is to put on all your sterile gear, except for the gloves. Before wearing your sterile gloves, you need to open the pouch containing the ultrasound cover. The pouch is sterile on the inside, and non-sterile on the outside. That is the reason why you want to manipulate the bag without gloves. It is essential to make sure that the pouch doesn't touch anything near your operation field.

Once the pouch is torn open, simply drop its content on a sterile surface. Usually, that surface is the sterile drape protecting your patient, but it can be any sterile sheet put on a table. If you choose the table, be aware that you should not place your item to close to the edge of the sterile sheet (if it does not entirely cover the table): the rule of the thumb is 1 inch from the edge.

Now that the cover and accessories (gel packet and elastic bands) are ready and waiting for you, you can go ahead and wear your gloves. You can now use non-sterile gel and apply a little of it on the lens of your transducer. Another option is to "fill" the cover with gel before introducing the probe. Then, pick up the cover over your dominant hand, and turn it inside out, so your hand is now on the inside of the cover. Grab the transducer, and gently unfurl the rest of the ultrasound cover. Make sure that the cover, especially the part protecting the cable doesn't touch any of the non-sterile environment. Check that no bubbles have formed over the lens. Now just secure the cover with the elastic bands. Usually, one goes around the "neck" of the transducer and the other further away on the cable.

To help you understand the steps described above, simply check out this video. Although we don't see the first stages of opening the pouch, it gives a pretty neat idea of how to insert the probe without contaminating the cover.

The pros and cons

The single-operator technique is suitable for smaller facilities where less personnel is available. It also gives the caregiver more control over his moves, decreasing the risks of misunderstanding and therefore the chances of breaching the sterile barrier. On the other hand, it requires more steps, more time and more attention from the healthcare professional.

The two-person technique

The two-person technique is when two operators are available. One is sterile, and the other is not. The same recommendations apply here: be sure to put in place a reproducible protocol.

The sterile person is wearing all his gear, including sterile gloves. He/She just needs to avoid contact with non-sterile surfaces/objects, but that's usual business. The non-sterile person now opens the pouch containing the ultrasound cover and drops the content on a sterile surface. He/She must give particular attention not to touch the inside of the bag. The same non-sterile operator then grabs the ultrasound probe and hold it vertically (with the lens pointing up).

The sterile professional puts sterile gel on the transducer lens. An alternative would be that the non-sterile person put non-sterile gel (dispenser bottle) on the probe, but we don't recommend that one (to learn more about it, please refer to this article)

Next, the sterile-one can take the sheath over his dominant hand and turn it inside out, pretty much like described above (and in the video). He/She catches the transducer, and the rest of the protocol remains the same: unroll along the cable, put on the rubber bands.

Pros and Cons

This technique saves more time as the sterile person can gear up (gloves, mask, gown) all at once. Besides, he/she is less likely to accidentally touch a non-sterile surface or object as he/she has fewer steps to go through.

The main drawback here is the need for a qualified 2nd operator to help. You also want to make sure that everyone knows his/her role in order to prevent an unwanted sterile field breach.

Bottom line

If you have the choice, you should go with the two-person technique. We recommend this one because it allows the caregiver to get ready in less time and generally reduces the risks of making an aseptic error. However, we know that you might not be able/eager to use two people on putting an ultrasound cover on a transducer. Therefore we suggest that, regardless of the technique you choose, you should follow the steps presented in this article. Finally, if you want more tips for maintaining a sterile field, you might want to read the 10 Areas of Focus for Maintaining a Sterile Field

Thank you for reading!