Certified Wound Ostomy Nurse (CWON) Practice Test

What is a key principle of how negative pressure wound therapy (NPWT) operates?

1. Increases blood flow through direct massage of the wound

2. Reduces edema and eliminates pooled exudate

3. Enhances oxygen supply to the tissue

4. Utilizes moist wound healing exclusively

The correct answer is: Reduces edema and eliminates pooled exudate

Negative pressure wound therapy (NPWT) primarily operates by creating a vacuum environment around a wound, which plays a crucial role in reducing edema and eliminating pooled exudate. This negative pressure facilitates the drainage of excess fluid and exudate from the wound area, which can otherwise impede healing by fostering a moist environment that encourages bacterial growth and prolongs inflammation. By drawing out this fluid, NPWT helps to not only decrease swelling but also promotes a favorable environment for healing by allowing granulation tissue to form more effectively. This principle is essential for managing wounds, especially chronic and complex ones, as it helps to maintain a clean wound bed and stimulates tissue regeneration. In this context, while other principles such as enhancing oxygen supply and promoting moist wound healing may be indirectly influenced by NPWT, the primary and most direct mechanism of action is linked to the reduction of edema and drainage of exudate, making this the key principle behind NPWT's operation.