Final answer:
Alginate dressings are used to treat stage 3 and 4 pressure injuries to absorb drainage and promote wound healing.
Step-by-step explanation:
Alginate dressings are used to treat stage 3 and 4 pressure injuries to absorb drainage. When in contact with drainage, alginate dressings form a soft gel. These dressings are made from seaweed and contain a high content of sodium and calcium ions, which help promote wound healing. They are especially useful for wounds with moderate to heavy exudate (drainage). Alginate dressings can absorb a large amount of fluid while maintaining a moist environment for wound healing.