a Wound Vac Sucks If You Do It Right

Wound vacs have been around for quite a while and I find them a challenge, but I love wound care and I love vacs.

KCI is the company that pretty much has a corner on the market but you may from time to time see other brands. I've found quite a few good videos for you to review the procedure using models or illustrations. I followed them up with actual wounds because, well, there is nothing like seeing something on a real patient. 

So let's begin...

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4 Part Video Demonstrating KCI Wound Vac Application

If you want just a quick run through on dressing application, go to KCI basic wound vac instructional video here.

KCI's SensaTrac 

A short explanation on how the little suction tube works.

Using the KCI pre-made Bridge

When you have a wound that is in an awkward spot or pressure point area, the tubing needs to be placed elsewhere. You don't want the patient lying on it and causing pressure ulcers or pain. The bridge allows alternate placement of the tubing to a more appropriate spot on the body.

You can order these bridges along with your other wound vac supplies. 

The reason for using a bridge in this case is because when you apply the compression wrap you don't want hard plastic tubing pressing into the leg and cutting off circulation. Review application of compression wraps on lower extremities here.

Make Your Own Bridge

With nursing being what it is, you know at some point, you will not have all the supplies you need when you need them. So, here is how you make your own bridge for a vac dressing.

Remember, always have a sheet of the drape UNDER the bridge you are creating. If you don't, the black foam will suck on the intact skin and cause a wound.  See the KCI wound vac bridge application video here.

KCI's 7 Day Disposable Vac

I saw these briefly when hospitals had to postpone patient discharges because the home wound vac machine had not yet been delivered.

I'm not sure how many acute care patients need a wound vac for only 7 days, but if there are quite a few then it makes sense to have disposables available.

KCI's Vac Ulta VeraFlo

This little pup not only provides negative pressure wound care, it also instills and removes wound solutions automatically and intermittently.

You can see here, how the spiral foam can be easier to use in some cases.

For more info, click on the link for: KCI wound vac Ulta (inpatient) here.

KCI's ABThera wound vac for Open Abdominal Wounds

Not to worry, this is applied by a surgeon. But if you are in an acute care setting you may see one of these.

KCI's Prevena Incisional Wound Vac Dressing

This is specifically for incisions. I have not used this nor seen one used on any patient, but good to know just in case.

In case you want some info on the fly, the KCI dressing change reference guide PDF can be viewed and printed here.

Using KCI White Foam

While black foam is used for the majority of wounds, there is an alternative, white foam. There are times when the white foam available for the wound vac is more appropriate. 

  • For lightly packing tunnels and undermining, while protecting delicate tissue.
  • Help promote graft take because it is less adherent than the black foam.
  • High tensile strength makes it easy to place and remove from tunnels and undermined areas. Black foam can tear too easily and leave pieces in the tunnel you will never see.
  • Increased density for restricted in-growth of granulation tissue for a more comfortable dressing change. However, healing tends to be slower.
  • Unlike the black foam that comes dry, the white foam is pre-moistened with sterile water.

While KCI is best known, there are other NPWT (negative pressure wound treatment) systems such as these:

Devon's extriCare

Talley's Venturi

SMith & Nephew's EZCare and V1sta

SMith & Nephew's Renasys

Smith & Nephew's PICO

Medela's Invia

Avance's NPWT


  • Never throw out extra drape after you have completed a dressing change. Save it because at some point you may need more for the dressing. Of course, don't share supplies between patients.
  • If foam sticks to your patient's wound, before you remove it, make a slit in the top of the drape and pour or syringe in NSS and let it sit for 5 -10 minutes to help loosen it.
  • Ask your patient to pre-medicate with pain medication about 30 minutes before you start.
  • Use a single layer of adaptic (oil emulsion dressing) over any exposed bone, blood vessels, tendons if approved by the physician. Otherwise do not use the vac on any of those exposed structures.
  • Use strips of drape around the margins of the wound to protect the intact skin if there is a possibility of black foam touching it. Some videos show them placing a drape over the wound and then cutting a hole. I'm too concerned I'd nip the patient using that technique.
  • If the main dressing is big and bulky, instead of using one big drape, cut it in wide strips and apply over the foam one by one, making sure to have some overlap of each strip.
  • Have as few layers of drape over the wound as possible.
  • Make sure that there is a big enough piece of foam for the entire sensitrack suction cup to sit. If you need to cut a second piece of foam and place over the hole in the drape, that is fine. The spiral dressing has one end that is wider and round. Just the perfect size to put the suction cup especially if you are making a bridge for the wound.
  • When placing the sensitrack make sure it isn't placed in an awkward place like on the abdomen right where a patient would bend. It will be uncomfortable as well as pull on the dressing. Make a bridge.
  • Once the sensitrack is placed, you cannot reposition it. So check with the patient first as to which direction they want the tubing to go (right, left, up down?).
  • Your enemy is the leak alarm. Putting your ear close to the dressing you can hear the hissing of air if there is a leak. Or gently press different areas until you see the suction increase and the alarm stop. Makes for an interesting nurse/patient relationship when you have to tell them you are going to listen to see if their butt hisses. (Sacral area dressings are the hardest to maintain)
  • You can use skin prep around the intact skin before placing the drape to help with adherence and protect the skin as the dressing is removed.
  • Leave the dressing on no more than 2 hours if the vac malfunctions.
  • Sometimes little pieces of black foam will remain in the wound bed. These need to be gently removed before re applying a new dressing.
  • You can cleanse the wound with NSS or wound cleanser.
  • In order to remember the order of removing the backing on the drape, recite, "1,1,2,blue". 
  • The hole in the drape that the sensitrack goes on should be at least the size of a quarter. 
  • You can secure the tubing further down the body with strip of drape.
  • The vac is usually set at 125mmHg but the physician orders what s/he wants. It is usually continuous suction, though intermittant is also possible. 
  • The container that holds the drainage has a little white packet that should burst open when fluid enters the chamber so it will turn the fluid into a solid for less chance of leaking. Sometimes these are defective, so call KCI or whatever company the supplies are from to get new cassettes.
  • Black foam comes in a variety of shapes and sizes. The physician has to decide black or white foam and the amount of suction but the nurse can decide whether small or large or spiral foam works best. And of course the insurance company may decide it doesn't want to pay for the pre-made bridge dressing which leaves to to make one yourself. 
  • The spiral foam is handy if you have a wound with undermining as it can be tucked into those areas easier than a big piece of foam. If you don't have the spiral foam you can cut the large black foam on it's edge, circling inward.
  • Remind the doctor that the patient is on anticoagulants to see if s/he would want any change in wound care orders. Patients on blood thinners will have bloody drainage and may not be appropriate for this type of wound care.
  • If you work in home care and get a patient newly discharged from the hospital, the original orders may read QOD (every other day) which means that visits would be needed on the weekends when there is less available staff. You could call the doc to see if s/he would be willing to change the order to Monday - Wednesday -  Friday.
  • There are dressings pre-made for the heel area, a typically difficult area to dress.
  • You can teach your patient to change the canister if it becomes full between home visits.
  • Get an order from the physician ahead of time allowing replacement of the vac with a NSS wet to moist dressing (not wet to dry) if there are problems with the wound vac function. (helpful for night time issues for home care patients).
  • The tube connection pieces are just plastic. Make sure you press the two ends of the tube together before twisting or you could break the little tabs off.

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