Wound, Ostomy and Continence Nurses Society (WOCN) Practice Exam

What is the mechanism of action for negative pressure wound therapy?

1. Increases oxygen levels to the wound

2. Reduces edema and eliminates pooled exudate

3. Enhances infection control through antibiotics

4. Promotes the use of growth factors in wound healing

The correct answer is: Reduces edema and eliminates pooled exudate

Negative pressure wound therapy (NPWT) primarily works by creating a controlled negative pressure environment over the wound, which effectively reduces edema and removes excess wound exudate. By applying negative pressure, the therapy encourages the contraction of the wound edges and promotes the formation of healthy granulation tissue, thus facilitating a more optimal healing environment. This reduction in edema is crucial since excess fluid can impede cellular and vascular function within the wound bed, hindering healing processes. Additionally, by eliminating pooled exudate, NPWT helps prevent the growth of bacteria and decreases the risk of infection, further promoting healing. While increasing oxygen levels, enhancing infection control, and promoting growth factors are important aspects of wound healing, they are not the primary mechanisms by which NPWT operates. Instead, the most significant effect comes from its ability to manage fluid and edema effectively, which creates conditions conducive to faster and more efficient healing.