Negative Pressure Wound Therapy (NPWT)

What is negative pressure wound therapy?

Negative pressure wound therapy (NPWT), also called wound vac therapy, VAC therapy, or vacuum assisted wound closure, is a treatment that helps wounds heal. It uses a medical device to apply gentle suction to a wound. 

Illness or treatment can cause wounds to heal slowly. This is known as delayed wound healing. Slow healing can result in infection and other problems.  

NPWT is used for different types of wounds. It can be especially helpful for wounds that are hard to treat or slow to heal. 

Some patients may need NPWT for a few days. Others may need it for several months.

How NPWT works

During NPWT, a special foam dressing is placed on the wound and covered by a film dressing. A suction tube is attached to the dressing. The wound vac applies negative pressure (suction). 

This therapy helps the healing process because it:

• Removes fluid and bacteria from the wound
• Reduces swelling in the area
• Helps the edges of the wound come together
• Increases blood flow to the area
• Reduces the number of dressing changes
• Prevents the dressing from shifting easily with movement
• Protects the wound and surrounding skin

What to expect during NPWT

General steps of NPWT include:

• Cleaning the wound and the skin around it
• Placing a dressing in the shape of the wound over the site
• Covering the area with a clear adhesive film (drape) to seal the skin and protect the wound from infection
• Placing a vacuum tube over the film
• Connecting a tube to the small portable suction pump
• Turning on the power to the wound vac machine

When the pump suction is on, it removes air from the wound site. For most patients, a wound vac does not cause added pain. When the suction starts and the dressing pulls inward (collapses), your child may feel a slight pull. This feeling usually goes away after a few minutes. Some patients may feel pain when the dressing pulls in, but this discomfort is about the same as other wound care procedures.

The suction also gently pulls fluid from the wound. This can help clean the wound and reduce swelling. The fluid passes through the tube and collects in a canister attached to a pump, which stays on until the dressing change. 

The suction may run all the time (continuous) or only at certain times (cycle). Your care team will decide how much negative pressure your child needs.

Possible risks or side effects of NPWT

As the wound heals, the area may become itchy or uncomfortable. Rare risks of NPWT include bleeding or infection.

NPWT at home 

If your child goes home with a portable wound vac machine, your care team will teach you how to use the pump. Your child can do most daily activities with the machine. But talk to your care team about what activities to limit or avoid. Ask them about instructions for showering or bathing.   

Parts of a wound vac machine

Most portable wound vac machines have these main parts:

• Therapy unit (pump) that creates suction
• Canister or layer that collects fluid
• Sterile plastic tubing that delivers suction
• A special foam dressing that is placed over the wound
• A sticky film or protective layer (clear waterproof drape) that covers the dressing

See the user manual for help using your system. Check the device often and make sure that:

• The pump is on 
• The foam dressing has collapsed (pulled in from the suction)
• No air leaks from the drape or tubing
• The battery is charged

Wound vac machine alarms

The therapy unit will beep or sound an alarm if a problem occurs. Most alarms happen because:

• The pump is not active or is off.
• The battery is low (always take the power cord with you).
• There is a leak, loss of suction, or blockage.
• The canister is full and needs changing.

Changing the canister and dressing

Your care team will usually change a full canister at your child’s clinic. They may teach you how to remove and replace the canister if needed. You may also learn how to repair leaks in the drape.

The dressing and tubing should be changed at least once a week (or more often, depending on the wound). Follow your care team’s directions. They may suggest medicine and other ways to manage pain during dressing changes.

When to call your care team

Let your care team know if your child's pain or discomfort increases or if there are signs of infection. Contact your care team if your child has signs or symptoms of infection, such as:

• Increased discomfort, pain, or swelling
• Increased redness, odor, or warmth around the wound
• Fever, weakness, or dizziness
• The fluid in the canister looks different in color or consistency
• Increased bleeding
• Skin rash or severe itching 
• Suction machine stops working, urgent rtc

Let your care team know if the wound vac system is off for more than 2 hours or if you have problems with the device. 

Questions to ask your care team

• Why does my child need NPWT?
• How long will my child need to use NPWT?
• Are there any risks of NPWT?
• How can my child shower or bathe during NPWT?
• How can I help my child manage any pain with dressing changes?
• Who should I call if my child has side effects such as bleeding or infection?
• When can my child return to everyday activities?
• When should my child NOT use NPWT?

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