Negative Pressure Therapy Demonstration- Part 2

In Part 2 of the Negative Pressure Therapy Demonstration, Japa Volchok, DO discusses proper wound prep and dressing application. This is a step-by-step instruction of preparing a wound for negative pressure therapy, or “Wound V.A.C. therapy. This demonstration is performed by a trained wound care physician for educational purposes only and should not be tried at home.


Understand Wound Care:
Negative Pressure Therapy Demonstration- Part 2
Wound Prep & Dressing Application
Commentary: Japa Volchok, DO

If negative pressure therapy has been ordered for your patient and is now time to apply the dressing, it is useful to have additional items available. These would include several packets of skin prep, as well as a suture removal kit. It is important to maintain the sterility of the dressing packages up to the time of application.

At the time of dressing application, it is important to follow standard precautions. It is not a sterile procedure, so there’s not a need for sterile gloves. It is not necessary to perform a surgical prep of the wound. There are instances in the acute setting when a negative therapy dressing may be applied in a sterile environment. However, for the purposes of this demonstration we are performing a clean procedure.

Once you have selected the appropriate size of the sponge based on the wound defect to be filled, you can then open the packaging and proceed with the application of the dressing.

This demonstration is an artificial wound model that has been supplied to us by K.C.I. You’re seeing here that the patient has an ischial ulcer that is a stage 4 ulcer. There are muscle fibers present in the base of the wound. This wound has no evidence of necrotic tissue and is beginning to granulate. This would be an indication for negative pressure therapy. And, negative pressure therapy would be used to promote wound healing by reducing edema in the surrounding wound bed as well as removing exudates and other fluids that may be present in the wound.

There’s no evidence of necrotic eschar or active infection. So, this makes it a fairly straight forward application of a negative pressure dressing. Once we have identified our wound, measured it, staged it and verified that the orders are correct for negative pressure therapy.

We would go ahead and select an appropriate sponge. This sponge, as you can see, is much larger than the wound. It is now useful to have sterile scissors or a sterile scalpel. We can now begin to cut the foam dressing to a size that is slightly smaller than the wound. It is important to cut the dressing over a clean surface and not over the wound so that particles of the foam dressing do not fall into the wound.

Once the foam has been cut and shaped to a dimension that approximates that of the wound, we would gently insert it into the wound.

When shaping the foam dressing for application into the wound, care should be taken that the foam approximates the size of the wound defect. And, when negative pressure is applied, it should just fill the wound or slightly under-fill the wound. You do not want to have a dressing that fills the wound such that when negative pressure is applied there is now sponge dressing on top of healthy skin.

There are two methods to prevent the sponge from overlapping healthy tissue. One is to correctly size the sponge initially so that when negative pressure is applied, it does not overlap normal skin.

Another method is to use your adhesive dressing to create a barrier around the wound to exclude the healthy skin from the foam dressing. This would be achieved by cutting a portion of your adhesive dressing, removing “number 1,” occluding the wound, removing layer “number 2,” and tearing off the leading edge.

We would now then cut out the dressing around the area keeping the normal skin covered with the adhesive dressing. We would then insert the sponge. Now you can see that even though the sponge is above and covers the edge of the wound, on to normal skin, the initial layer of adhesive dressing provides a barrier.

Once we have sized the foam dressing appropriately, we are now ready to apply the dressing and the adhesive barrier that will achieve a vacuum seal for negative pressure therapy.

Initially, we would like to take skin prep and prep around the wound so that the adhesive will more readily adhere. Once this has occurred and we have inserted the foam dressing into the wound, we would select an appropriate sized piece of the adhesive covering. Using our scissors this could then be cut to an appropriate size.

When working with the adhesive, it is generally easier to use if we cut in a direction that allows all edges of the adhesive backing removal to be readily accessible. A dressing that has been completely cut free from the leading edge is now very difficult to peel the layers apart.

This dressing has an initial layer that is removed from the adhesive and discarded. After removing the initial, lay that down on the skin and rotate that up. Now, we would start to slowly pull the dressing backing off as we stick the adhesive down surrounding the wound.

Once this has occurred and we have achieved circumferential adherence of the adhesive. The secondary layer, which is a layer of thickness that is added to for ease of working, is removed. This is what is labled as “number 2.” Once that has occurred, we can remove the blue leading edge. This is included for ease of work.

Now we have the wound filled with an appropriate sized negative pressure therapy sponge dressing. It has not occluded, or covered, healthy normal skin.

We have now completed the initial application of the negative pressure therapy sponge dressing and the adhesive secondary dressing. At this point we are ready to connect the sponge dressing to the negative pressure source. This is achieved using the supplied tubing and the adhesion system.

In application of the tubing that is connected to the negative pressure generator, this tubing is supplied with an adhesive and a working backing that is then secondarily removed. At this point, our sponge is completely occluded by the film adhesive dressing. The first task is to remove a portion of the adhesive dressing over the sponge. This can be accomplished in a variety of manners. The simplest is to use a pair of scissors and cut out a portion of the adhesive. It is not a problem if you also remove part of the adherent sponge. It actually makes this an easier process. It is important to have an adequate size opening to the sponge, through the adhesive so that the negative pressure tubing is not occluded when it is attached.

Remove the backing and place the negative pressure device centered over the hole that you made in the adhesive dressing. You can now remove the secondary portion and the overlying working backing. This splits apart. We now see that we have applied the negative suction tubing over the negative pressure sponge dressing and the adhesive barrier.

We have cut an appropriate size hole in the adhesive barrier and the negative pressure tubing is now placed over that and is well adhered. At this point, the wound has been appropriately dressed with the negative pressure therapy sponge dressing and its components. We are now ready to connect the tubing to the negative pressure therapy generator.

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