Para/Medic: Wound VAC Therapy

By | 2017-01-13T20:42:52+00:00 November 1st, 2013|
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Bob VogelQ. I’m a T3 para, just now back in my chair after spending many months in bed healing a small pressure sore that was right over my left ischium (butt bone). I managed to heal it on my own, but the toughest part of the healing process was having to constantly change the dressing because the sore kept draining and soaking through.

A friend of mine, also a wheeler, gave me a lot of grief for not going to see a wound care specialist. He also said a wound care specialist would probably have prescribed a wound vac, which would have enabled me to heal much faster.

What is a wound vac and how does it work? Does Medicare cover it? And if it is used on a pressure sore on your butt, can you still get up in your chair? Even though I stayed in bed while healing, I still needed to get up for the bathroom and meals.
— Dan

A. Dan, I’m glad your pressure sore is healed. However, your friend is right on both counts. Cherisse Tebben, family nurse practitioner and certified wound care nurse at Craig Hospital, says that any time you see the beginnings of a pressure sore, it is important to visit your doctor and ask for a referral to see a wound care specialist. The same holds true for burns or any other type of skin breakdown that doesn’t heal right away. Different wounds and different stages of wound healing require specific management techniques to maximize healing, and wound care specialists have the training and specialized skill set to give you the best chance for fast healing.

As for wound VACs, they first came onto the scene in 1995. VAC stands for vacuum assisted closure, also known as negative pressure wound therapy because it uses negative pressure (a vacuum) to heal wounds. VAC has become an important part of wound therapy over the past decade.

The VAC system speeds healing in three main ways, says Tebben. It reduces edema (swelling) in surrounding tissues, which left unchecked impairs blood flow needed to bring wound-healing nutrients. It also removes exudate (the fluid that drains from a wound) and creates a desired moist wound-healing environment, rather than a wet environment from too much exudate, which causes the skin to become macerated (soggy) and slows healing, or a dry environment. And it enhances granulation (new connective tissue and tiny blood vessels that fill in and help heal the wound) by bringing enhanced bloodflow to the wound. In addition, there is some evidence that bacterial counts may be reduced, but overall results in clinical trials are mixed.

Tebben explains that VAC therapy is completely different from hyperbaric therapy, which promotes healing by using oxygen under positive pressure to increase the oxygenation of cells and helps kill off bad bacteria.

To apply a VAC system, first a “drape,” or thin, waterproof transparent adhesive plastic covering is placed around the perimeter of the wound to protect the surrounding skin. Next, a sponge-like foam is cut to the shape of the wound and placed in the wound. According to Tebben, there are different types of foams. If the wound has heavy drainage, a more porous foam is used. If infection is present, a silver-impregnated foam is used to fight bacteria. The foam ensures there is an even vacuum over the entire wound. The next step is to cover the entire area with a second layer of waterproof transparent dressing. Next, a small hole is cut over the foam and a vacuum tube fitted with a round adhesive film is sealed over the hole. The vacuum tube goes to an enclosed pump fitted with a canister to catch the drainage.

When the pump is turned on, the dressing sucks the foam down and creates the seal. At this point the wound care specialist adjusts the vacuum pressure specifically to the patient and wound, and the healing process begins. The VAC stays on 24 hours a day.

Portability and Healing at Home
Depending on wound size and drainage, different-size VAC pumps can be used. VAC pumps run on batteries, which are periodically recharged with a plug-in charger. Smaller VAC pumps are portable and can be carried around. Tebben says they all make noise, about the same as an aquarium pump. They also have an alarm built into them to let you know if the seal has broken—something that must be addressed in a timely manner or the air tight wound dressing will fill with drainage and the wound will become macerated.

With VAC therapy you can heal at home. The dressing is usually changed every two to three days by a home health care professional and is periodically checked by a doctor. Wound care professionals encourage family members and caregivers to learn about the device and how to troubleshoot in case a seal breaks loose during the night.

“With VAC therapy you can tell if it is working within a couple of weeks, and when it works the healing speed can be very dramatic,” says Tebben. “We order VACs all the time. When the wound heals fast, we sometimes put some Xeroform in the wound, a fine-mesh gauze impregnated with a non-stick coating to prevent the granulation from sticking to the sponge between dressing changes.”

When placing a VAC dressing on an ischium or sacral sore, Tebben says a wound care professional will cut sections of sponge and create what they call a bridge, a channel of sponge that runs from the wound to the hip. The tubing goes in the channel, which protects healthy skin from pressure. The whole channel is covered with clear dressing. This way a person can sit up for short periods of time for meals, bowel program, and general mental health — a maximum of three times a day for about an hour or less.

Almost any type of wound can be treated with VAC therapy provided a seal can be maintained, including pressure ulcers, diabetic foot ulcers, trauma wounds, burns, leg ulcers, skin grafts, and flaps, according to

There are a few contraindications for using a wound VAC. Large areas of necrotic tissue (dead tissue) must be removed before use. It can’t be used over bodily organs, on non-resolved osteomyelitis, or a wound that has large blood vessels in it. If a person has hemophilia or is on blood thinners, the doctor and wound care specialist will decide if VAC therapy is appropriate. And because it needs a good seal, a VAC dressing doesn’t work close to the rectum where the skin is moist. Also, if skin surrounding the wound becomes irritated, a doctor may advise that VAC therapy be temporarily suspended until the irritation resolves.

According to, Medicare will cover rental of a VAC pump, 15 dressing kits and 10 drainage kits per month if your physician deems it medically reasonable. Medicare will also cover in-home dressing changes and wound care by a provider or home health agency approved by the Medicare program. It is likely that private insurance will cover VAC therapy as well. As always, check with your insurance provider first.

Dan, I hope this information helps, and now that your pressure sore is healed, I hope you never need it!

Advice in this column is supported by Craig Hospital’s SCI Nurse Advice Line, a toll-free hotline for people living with SCI, a community service partially funded by grants from the PVA Education Foundation, Craig H. Nielsen Foundation and Caring for Colorado Foundation. For non-emergency nursing information about SCI health, call 800/247-0257 between 9 a.m. and 4 p.m. Mountain time. If you have a health question, contact Bob Vogel at