Patient education: Negative pressure wound therapy (The Basics)

What is negative pressure wound therapy? — Negative pressure wound therapy, or "NPWT," is a special kind of dressing for open wounds (figure 1). It might also be called "vacuum-assisted wound closure," "wound VAC," or "VAC therapy." There are different types of NPWT systems.

NPWT can be used on some types of wounds that are healing very slowly or wounds that are large. This helps with healing. Sometimes, it can be used on closed incisions to help prevent wound infection.

With NPWT, thin tubing connects the dressing to a machine. The machine creates a suction or vacuum to pull fluid out of the wound. It also affects the surface of the wound to help it heal. The suction can be on all the time, or can be set to go on and off at certain times.

You need to change the dressing and tubing every 2 to 5 days. You might need a family member or friend to help you with wound care. Some people have a home health nurse come to their home to help.

What happens during a dressing change? — First, turn off the machine, remove the old dressing, and check that there are no bits of dressing left on the wound. If the dressing is sticking to the wound, wet the dressing to help loosen it before you take it off. Clean the wound, and note its size and color. Also note what the edges of the skin look like.

To apply a new dressing:

●Clean the wound, and clean and dry the skin around the wound. Some people put a skin protectant or clear dressing on the skin around the wound. This will protect the skin and help get a better seal.

●Cut the new dressing to the size and shape of the wound. The dressing should fill the wound, close to the top, but should not touch any healthy skin around the wound.

●Put a clear adhesive bandage over the dressing. This should extend onto the skin around the wound about 1/2 inch (1 cm) on all sides to make a full seal.

●Make a small hole in the clear bandage over the dressing. Place the suction tubing in the hole, and connect the tubing to the NPWT machine.

●Turn the NWPT machine to the right settings, and check for air leaks. The dressing will sink into the wound if there are no air leaks.

What happens after a dressing change? — The suction container on the NPWT machine will collect any drainage from the wound. You need to:

●Take extra care not to kink or pull on the tubing.

●Empty the container when it is about half full or at set times during the day.

●Measure the amount of drainage each time you empty the container. Write down the amount of drainage, what color it is, and if it has a smell.

●Know how to care for the tube if there is a clot in it. The doctor might tell you to squeeze the tube over the clot to open up the tube.

What are the risks of NPWT? — Your doctor will talk to you about all of the possible risks, and answer your questions. Possible risks include:

●Bleeding

●Pain

●Wound infection

●A clot in the suction tubing

What else should I know? — Before you go home, make sure that you know what problems to look out for and when you should call the doctor. Make sure that you understand your doctor or nurse's instructions. Ask questions about anything you do not understand.

●Make sure you know how to use the NPWT machine and what to do if the pump stops working.

●Wash your hands every time before and after you empty the drain or change your bandage (figure 2).

●Do not swim or soak your wound in water while the NPWT dressing is in place. You can shower normally and pat the area dry afterward.

•Before you shower, turn off the machine, and clamp and disconnect the tube from the machine.

•The dressing will expand under the clear bandage, which is OK.

•Don't forget to reconnect the tubing to the NPWT machine, unclamp it, and turn the machine back on as soon as you are finished showering. The dressing should sink back into the wound.

●Avoid activities where you might pull on the dressing or tubing.

When should I call the doctor? — Call for advice if:

●You have a fever of 100.4°F (38°C) or higher, or chills.

●You have bleeding.

●You have skin color changes, swelling, or pain around the dressing.

●The drainage becomes cloudy or has a foul smell.

●The NPWT machine is not working.

More on this topic

Patient education: Caring for an open surgical wound (The Basics)
Patient education: Surgical site infection (The Basics)