The Vacuum-Assisted Closure (VAC) system, also known as Negative Pressure Wound Therapy (NPWT), promotes healing in complex or chronic wounds. This non-surgical treatment uses a gentle vacuum pump to create controlled sub-atmospheric pressure across the wound site. Negative pressure draws the wound edges together, removing excess fluid and infectious materials into a collection canister. By increasing blood flow and encouraging granulation tissue, the VAC system optimizes the wound bed for closure. Regular dressing changes are fundamental to maintaining this therapeutic environment.
Essential Preparation and Required Supplies
A successful dressing change begins with thorough preparation to maintain a sterile field and minimize the time the wound is exposed. Begin with meticulous hand hygiene before setting up the sterile field. Don clean, non-sterile gloves for the removal process. Confirm the patient is comfortable and positioned so the wound is fully accessible.
The VAC unit must be turned off, and the tubing leading to the dressing should be clamped securely to prevent fluid reflux and contamination before disconnection. Gather a comprehensive set of supplies.
Required Supplies
- New sterile foam or gauze dressing
- Sterile transparent adhesive drape
- Skin barrier wipe
- Sterile saline solution for cleaning
- New collection canister (if needed)
- Waste bag
- Sterile scissors to cut the foam and drape
- New SensaT.R.A.C.™ Pad or connector
Removing the Old Dressing
The removal process must be executed with care to avoid trauma to the delicate, newly formed tissue. First, locate the tubing connector and gently disconnect it, ensuring both clamps are closed beforehand. Peel the transparent adhesive drape away from the skin’s surface by starting at one edge and pulling it slowly and parallel to the skin. Pulling the drape upward can cause unnecessary skin stripping or discomfort.
Once the adhesive drape is lifted, remove the foam or gauze within the wound bed. If the foam is adhered to the granulation tissue, instill sterile saline solution directly onto the foam to help loosen the attachment. Allowing the saline to soak for several minutes minimizes the risk of bleeding or tissue damage during extraction. After removal, count the pieces to ensure all material is accounted for. Dispose of the contaminated dressing and old gloves immediately.
Applying the New Dressing and Sealing the System
Before applying new materials, assess the wound and surrounding skin for healing progress and ensure a clean surface. The wound bed should be gently cleaned with sterile saline solution to remove residual exudate or debris. Pat the surrounding periwound skin dry to promote optimal drape adhesion. Visually inspect the wound for signs of healing, such as healthy granulation tissue, or concerning changes like increased size or excessive drainage.
Apply a protective skin barrier wipe to the intact skin around the perimeter where the transparent drape will adhere. This protects the skin from the strong adhesive and moisture. The new foam dressing must be precisely cut to the exact size and shape of the wound cavity using sterile scissors. Ensure the foam completely fills the space without overlapping onto the intact skin. Cut the foam over a clean surface, not directly over the wound, to prevent particles from falling into the wound bed.
Place the foam into the cavity, ensuring it contacts all wound surfaces. Apply the transparent adhesive drape over the foam and surrounding skin, extending at least two to three centimeters beyond the wound edges. This creates a secure, wrinkle-free, and airtight seal. Wrinkles or creases compromise the necessary vacuum seal. Next, cut a small, circular hole (about 2.5 centimeters in diameter) into the drape directly over the foam, avoiding the underlying skin.
Place the SensaT.R.A.C.™ Pad or connector with its central disc directly over the hole. Smooth the adhesive skirt down firmly to bond with the transparent film and the skin barrier. Once the port is secured, connect the tubing from the SensaT.R.A.C.™ Pad to the canister tubing. Open the clamps and turn the VAC unit back on to initiate negative pressure therapy at the prescribed setting. A proper seal is confirmed when the transparent drape collapses and the foam appears compressed or wrinkled as the unit pulls a vacuum.
Monitoring and Troubleshooting Common Issues
Immediate monitoring after the dressing change confirms the system’s integrity and seal success. The most noticeable sign of a secure seal is the visual collapse and wrinkling of the transparent drape. An audible check is also important; distinct whistling or hissing sounds indicate an air leak that compromises negative pressure.
The VAC unit often displays an alarm message if the system is not functioning correctly, commonly “leak detected” or “low pressure.” If a leak is suspected, check the entire dressing perimeter for lifting edges. A small strip of drape material can be used to patch the area. A “blockage” alarm requires checking the tubing for kinks or crimps and ensuring all clamps are fully open, or it may signal a full collection canister needing replacement. If the unit fails to maintain pressure despite troubleshooting, or if the dressing has been off for more than two hours, contact the healthcare provider.
The caregiver should monitor the patient for concerning systemic or local changes that signal complications. Contacting a healthcare professional is imperative if there is any sign of a developing infection, such as a fever, sudden increase in pain, foul odor, or excessive warmth and redness spreading around the site. The presence of a large volume of bright red blood in the tubing or canister is an urgent sign requiring immediate medical attention.