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Patient Education - Negative Pressure Wound Therapy

Patient Education - Negative Pressure Wound Therapy

Patient Education - Negative Pressure Wound Therapy


Negative pressure wound therapy (NPWT), also known as "wound vac", is a wound care treatment in which a foam dressing is placed on an open wound, is covered with a polyurethane drape, and then a vacuum (delivering negative pressure) provides suction and drains fluid to an attached canister.

This topic provides answers to questions frequently asked questions by patients, from how to receive/return a NPWT device, when and how a NPWT is removed, and how to use it. 

 Patient Education Handout (download)

WHAT is Negative Pressure Wound Therapy (NPWT)?

A foam dressing is placed on an open wound, is covered with a polyurethane drape, and then a vacuum (delivering negative pressure) provides suction and drains fluid to an attached canister (see Figures 1 and 2).

NPWT (also known as wound vac) promotes wound healing by:

  • Supporting growth of new tissue
  • Providing moist wound healing
  • Assisting closure of wound edges
  • Removing fluids and infectious materials 

Figure 1. Negative pressure wound therapy applied to a leg ulcer covered with black foam
Figure 2. Lateral view of negative pressure wound therapy applied to a leg ulcer filled with black foam

Receiving & Returning NPWT device

  • Upon receipt:
    • The NPWT device and supplies will arrive at your home. Please sign and return receipt the paperwork upon arrival.
  • Returning the device:
    • Upon stopping therapy, the wound vac company will be notified.
    • Follow the manufacturer's instructions to return the NPWT device

WHAT do I need to know about your NPWT device?

NPWT Device Battery

  • Intermittently charge the battery (takes 6 hours to fully charge).
  • The battery may last up to 14 hours if fully charged.
  • A battery indicator may be present on the unit screen, and a battery alarm will sound when low.

Dressing Changes

  • Occurs every 48 to 72 hours by a nurse.
  • Bring one canister and one dressing foam package to every appointment.
  • If dressing changes are painful:
    • Turn off the unit 30 minutes before your dressing change.
    • As directed by a clinician, take pain medication before the dressing change.

 NPWT Device Canister

  • Change once weekly and as needed if full.
  • Contains a white powder package that “gels” the contained drainage.
  • Your nurse will show you how to change the canister.

Showering with a NPWT Device.

  • Your NPWT device  should not get wet.
  • Do NOT take the NPWT device unit into the shower or bathtub.
  • You may shower immediately before wound vac dressing changes only if your provider has approved this activity.
*NPWT device  should not be turned off, lose suction, or be disconnected for more than 2 hours*

WHEN and HOW do I remove my NPWT device?


  • Before showering, power off the wound vac, disconnect from the unit, and clamp the tubing.
  • If therapy is off/interrupted for more than 2 hours, change the dressing immediately (see above) and:
  • Wash hands, remove drape and all foam pieces.
  • Clean the wound with saline or tap water, and apply an alternative dressing until seen.

NPWT Device Alarms & Concerns

NoiseThe unit makes a small amount of noise, however, this noise will become louder if there is a leak/poor seal.
CanisterA canister alarm will alert you to the need for a canister change. Change the canister as directed.
SuctionThe unit will display effective suction. If suction is lost, an alarm will sound. Your nurse will teach you how to troubleshoot and maintain suction.

If a sudden increase of blood from the wound is in the tubing or canister:

  • Turn off vac unit right away.
  • Apply pressure over the area.
  • DO NOT remove the dressing.
  • Call 911 and then call your provider or nurse.

WHEN should I call my healthcare provider?

Don’t wait or hesitate to contact your healthcare provider for: 

  • Questions regarding your home care instructions or NPWT device
  • Symptoms of infection: Fever, sweats, chills
  • New pain or uncontrolled pain
  • Redness or swelling of the skin surrounding the dressing
  • Abnormal smell or foul odor
  • Increased wound drainage
  • Green or yellow drainage
  • Blood in the tubing or canister 

If you are unable to reach the Wound Healing Center, call your primary care physician, Prompt Care or your local hospital emergency room.

Call the manufacturer if you have questions or concerns about wound vac outside of business hours or having trouble with the negative pressure wound therapy device

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NOTE: This is a controlled document. This document is not a substitute for proper training, experience, and exercising of professional judgment. While every effort has been made to ensure the accuracy of the contents, neither the authors nor the Wound Reference, Inc. give any guarantee as to the accuracy of the information contained in them nor accept any liability, with respect to loss, damage, injury or expense arising from any such errors or omissions in the contents of the work.
Topic 2431 Version 1.0