Wound Wise: Keep wounds moist with foam dressings 
Yvonne Avent MSN, APRN-BC, CCRN, WCC 

Nursing Made Incredibly Easy!
January/February 2010 
Volume 8 Number 1
Pages 17 - 19

You've just completed a thorough skin assessment of your patient and have identified a wound that needs to be managed. Wound care knowledge has changed significantly over the past several years, and technology has provided many options for treating wounds. With so many dressings from which to choose, where do you start? What factors should you consider when selecting the proper dressing?

In this article, I'll take a look at foam as a dressing choice, including a review of foam dressings, indications for their use, how they're applied, and when not to use them.

Form and function

One of the main goals of wound management is to provide an appropriate, moist environment for healing that will prevent cells from dying and promote cell migration. It's important to keep the wound bed moist and the periwound area dry. Foam dressings can provide this moist environment that's critical to wound healing. They also absorb exudate and protect the surrounding periwound area from maceration (see Picturing a foam dressing in action). The high absorbency rate of foam may also allow caregivers to increase the time between dressing changes. Often, a foam dressing may be left in place for 3 to 4 days.

Most foam dressings are made from polyurethane. The polyurethane contains variably sized small open cells that have the ability to pull exudate away from the wound bed. The dressings are absorbent and don't lint. Some foam dressings are made of a single layer, whereas others are thicker and have multiple layers. Many have a nonadhesive layer that allows for easy removal from a wound (see Adhesive vs. nonadhesive foam dressings).

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Foam dressings can be used for a wide range of wounds. Because of their absorptive ability, foam dressings are especially useful for wounds with moderate to heavy exudate production. This is important because wound exudate can impair healing and harbor bacteria that damage healthy granulating tissue. Therefore, the absorptive ability of a foam dressing must match the exudative property of the wound. A dressing labeled "lite" or "thin" won't absorb as much exudate as a product labeled "extra" or "plus."

Wounds that may benefit from foam dressing application include:

* leg ulcers

* pressure ulcers

* sutured wounds

* skin grafts

* donor sites

* minor burns

* wounds requiring negative pressure wound therapy (NPWT).

Foam dressings can also be used around tubes, such as tracheostomy and gastrostomy tubes, to absorb drainage and in conjunction with other types of dressings to manage heavily exudating wounds. Because they provide a moist healing environment, foam dressings can help promote autolytic debridement and inhibit the formation of hypergranulation tissue.

The ABCs of application

Foam dressings may be used as a primary or secondary dressing. If used as a primary dressing, the dressing is cut to allow for an extra margin greater than the size of the wound to protect the periwound area, and then placed directly over the wound. Foam dressings are flexible in that they can be cut to fit irregular wounds or specific body parts, such as fingers, toes, or ears. They can also be used under compression bandages with venous ulcers and can be cut to fit into a wound cavity. When placing a foam dressing in a cavity wound, it's important to remember to allow for dressing expansion as exudate is absorbed.

Foam dressing changes will depend on the specific manufacturer's recommendations regarding the dressing's ability to absorb and the amount of exudate that the wound is producing.

Foam dressings and NPWT

NPWT uses a mechanical device to deliver controlled negative pressure. The negative pressure assists in wound healing and closure by removing fluids, exudate, and bacteria from a wound. NPWT is achieved by placing an open-cell reticulated foam dressing into the wound and sealing it with a semiocclusive drape. Negative pressure is then applied by use of a computerized pump. The reticulated foam dressing is supplied by the company that provides the NPWT device. These foams ensure negative pressure is applied equally to all parts of the wound that are in contact with the foam. The dressing can be cut and trimmed to fit the surface of the wound and any tracts or tunnels that may be present.

Polyurethane foam is a black open-cell dressing that's used in NPWT. It supports wound contraction and growth of granulation tissue and is also useful in absorbing exudate. Polyvinyl foam is a white thick foam that's stronger than polyurethane. Polyvinyl can be premoistened with sterile water to promote the moist healing environment, and it may also be used with NPWT when a patient can't tolerate polyurethane foam or when it's necessary to control granulation tissue formation.

Be advised!

Dry wounds with a scab or eschar shouldn't be covered with foam dressings. Wounds with minimal drainage won't benefit from a foam dressing because the dressing may dry out the wound and decrease the moist healing environment. In addition, foam dressings aren't an appropriate choice for third-degree burns.

If a foam dressing is being soaked through with exudate, bacteria from an external source can enter the wound. In this instance, it's appropriate to either choose a more absorbent foam or consider another dressing type. Remember, the foam dressing must be able to effectively manage the exudative properties of the wound.

The flexibility of foam

Foam dressings have a wide variety of clinical applications and are beneficial for many wound types with moderate to heavy exudate. They're easy to use and flexible in that they can be cut to fit irregular wounds. And now you know more about them!

Learn more about it

Hess CT. Clinical Guide: Skin and Wound Care. 6th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2008:297–360.

Slachta PA. Caring for chronic wounds: a knowledge update. Am Nurse Today. 2008;3(7):27–32.

Sussman C, Bates-Jensen B. Wound Care: A Collaborative Practice Manual for Health Professionals. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2007:253–254, 688.

Wound Care Made Incredibly Visual! Philadelphia, PA: Lippincott Williams & Wilkins; 2008:160.