Negative Pressure Therapy Demonstration- Part 4

In Part 4 of the Negative Pressure Therapy Demonstration, Japa Volchok, DO discusses various tips and techniques. This is a step-by-step instruction of preparing a wound for negative pressure therapy. This demonstration is performed by a trained wound care physician for educational purposes only and should not be tried at home.


This video demonstration includes several tips and pointers that will allow you to correctly apply negative pressure therapy and achieve a successful dressing application. One common problem that may occur when applying a negative pressure dressing is it may be difficult to achieve a seal around a specific wound. Commonly, pressure ulcers develop in locations of the body where the skin’s surface area is varied in its texture and depth.

This is a sacral wound where you can see that within the cleft of the buttock here, there is a relative deficit. When applying the adhesive, it were laid flat, you would see that there’s a large defect here. To get the adhesive to stick and seal can sometimes be difficult.

One assist in achieving a good seal over the wound is to use an ostomy or stoma paste. Stoma paste is supplied by prescription or from your medical device vendor. It commonly comes in a tube. Sometimes it is in a strip or roll. What you can do with stoma paste, is apply it in the area where there is a defect in the skin, prior to applying your adhesive.

Once you’ve applied your stoma paste, you can then apply the adhesive directly over that as you will see in this demonstration. Your adhesive can stick directly to the stoma paste that has filled the deficit. You can gently mold the stoma paste with your fingers. This will greatly aid you in achieving a seal around the wound and over the negative pressure dressing or the sponge in this case.

It is not uncommon when applying your suction tubing that the tubing may run across a portion of the body where you would not want the patient to be laying on tubing. This suction device can be located elsewhere, off a site of support. To do that, we would construct a bridge.

There are several options for constructing a bridge. Some negative pressure devices, actually have pre-constructed bridging tubing. One example of that is demonstrated here.

If you prefer to construct a bridge without using a pre-made device, that is relatively easily done. The first step is to place your sponge dressing or other dressing into the wound. Take away a portion of the adhesive. Now select a site away from pressure where you would like the tubing to sit. In this case, we’re going to bring it off to the side as illustrated here.

What you would want to do first is to lay down a layer of adhesive dressing, from the wound extending to where you would like the negative pressure tubing to be located. In this case, off to the side. Once this has been lain down and the working layer has been removed, the next step is to cut a strip of your foam dressing, approximately the length of the distance between you wound and where you would like your pressure tubing to be located.

Once you have cut a piece of foam that extends from your wound to where you would like you negative pressure tubing to be located, you would then position that. Then, cover with another layer of adhesive. Once you have entirely sealed this second layer of your foam dressing, you’re now ready to peel this off.

You have now constructed a bridge that extends from over your primary dressing, where you’ve cut a hole in the sealant that covers the sponge that’s filling the wound. This is now on top of adhesive. It is not in contact with normal skin. It extends out to where you would like to position your tubing that will connect to the negative pressure generator.

Similarly, as we have done over the wound dressing, we cut a portion of the adhesive away. As I had said before, if you remove a portion of the sponge with this it’s not a problem. So, feel free to carve as you need with your scissors. Discard that.

You will now then take your tubing that connects to the negative pressure device, remove the adhesive, and this will go over the area where you have cut away the adhesive. Completely adhere that over and remove the backing.

Now you are ready to connect this tubing to the negative pressure generating device. You will see that once the negative pressure is active and is being generated by the device, this bridge will suction down. Any fluid or exudate will pull through the sponge that’s in the wound bed, come up through the hole that we had cut and come out through the bridge and through the tubing. The underside of this particular portion of foam dressing is in contact with adhesive and is not in contact with healthy skin.

This construction of a bridge allows you to locate your pressure tubing away from the wound site if the wound is relatively small. Or, locate the pressure tubing off an area where you don’t want it to be a point of contact. This would be over and area such as the back, where it would be uncomfortable for the patient to continuously lay on the tubing itself.

As you can see here, our dressing has negative pressure attached to it. The bridge has collapsed and been suctioned down as well as the dressing or the sponge which is in the wound itself. This is the appearance you would see with a well-sealed, well-constructed primary dressing with a bridge created off to the side. You will note that when the negative pressure has been applied to the wound that this particular wound now has a concave or indented appearance to it.

If you have wounds that have significant depth and they are deeper than the thickness of your sponge, you can create two layers of dressing where you stack a sponge on top of the other sponge. One indication that this might be something that you would consider is if you’ve connected your dressing to the negative pressure source and you have a very concave appearance to it, it would be a reason to consider two layers of sponge.

As in the previous demonstration, it is important to protect normal skin from coverage by the sponge dressing. And, it is important to achieve a seal around the entire wound. You can see that the stoma paste has allowed us to produce an excellent seal on this inferior aspect of the wound. Often times due to a patient’s movement or anatomy you cannot achieve an adequate seal.

There are several specific indications and contraindications to negative pressure therapy. One should carefully review the manufacturer’s educational materials and the indications for use of a specific dressing and negative pressure therapy system.

There are several points that should be taken into consideration. If a negative pressure dressing is malfunctioning and there’s an inability to achieve a seal, and the therapy is not active, there is a time constraint that should be considered before switching to another type of dressing. In addition, if blood is noted within the wound bed and there is blood collecting in the collection container, this would be a concern and should be brought to the medical practitioner’s attention.

The use of negative pressure therapy is a by prescription treatment modality and the ordering healthcare provider’s instructions should be followed. In addition, specific manufacturer’s instructions regarding individual types of dressings and specific negative pressure devices should be taken into consideration. This video is for educational purposes only.

The wound model in this demonstration as well as the negative pressure generator and the supplies, have all been donated by K.C.I. for educational purposes.

Leave a Reply