VOL: 99, ISSUE: 31, PAGE NO: 59
Jacqui Fletcher, BSc, RGN, is academic group leader, Department of Nursing and Midwifery, University of Hertfordshire, HatfieldFoam dressings are used for their absorbency and ability to conform to a wound. The way they handle fluid varies between brands. Simple foam dressings allow fluid to pass straight through while maintaining non-adherent contact with the wound. Other foams absorb fluid within the structure of the dressing and have horizontal wicking which spreads the fluid throughout the dressing, allowing greater absorbency (Thomas, 1990).
Foam dressings are used for their absorbency and ability to conform to a wound. The way they handle fluid varies between brands. Simple foam dressings allow fluid to pass straight through while maintaining non-adherent contact with the wound. Other foams absorb fluid within the structure of the dressing and have horizontal wicking which spreads the fluid throughout the dressing, allowing greater absorbency (Thomas, 1990).
Foam products are usually backed with a film that prevents strikethrough of exudates (leaking of exudates onto the outside of a dressing). Some companies also offer foam products with impregnated silver, which has antimicrobial properties.
Applying a foam dressing
A range of different shapes and designs of foam dressings are available to manage areas of the body where wounds are difficult to dress, for example, the heel and sacrum (Fig 1).
Many products are available with an adhesive backing. Adhesive dressings may be cut to conform to some wounds, but this usually increases the bulk of the dressing and additional tape may be required to secure it. When the dressing has absorbed fluid to its capacity, it may become heavy and pull on the skin.
Non-adhesive products require secondary fixation with tape, light retention bandages or tubular net-type products. However, this allows them to be used on very fragile skin on which adhesive products may cause further trauma to the surrounding skin.
Levels of exudate
Several manufacturers of foam offer a range of products for different levels of exudates. Thinner foams, designed to absorb less, are usually identified as 'Lite' or 'Thin', while more absorbent versions designed to absorb larger volumes are known as 'Plus' or 'Extra'.
Dressings subject to pressure
Some foams are able to hold the fluid they absorb even when under pressure. As well as being able to use them under compression bandages, this also has advantages in areas of the body that are subject to pressure from body weight, such as the bottom or heel (Morgan, 2000).
This ability to retain fluid reduces the likelihood of maceration and excoriation to the surrounding skin. It also reduces the chance of the dressing leaking, so preventing possible distress or embarrassment to the patient.
Many practitioners use foams for their cushioning effect, particularly over hips and heels. While they may provide a little protection, they do not relieve pressure and so should not be used in place of appropriate equipment that redistributes pressure.
Cavity foam dressings
These may be preformed (Fig 2) or made to fit the shape of the wound. Preformed dressings are single-use only and available in a small range of shapes and sizes.
The custom-made product may be reused as long as it is cleaned according to the manufacturer's instructions. This type of product is only suitable for use on wounds where the entrance of the wound is larger than the underlying cavity.
This is because once the product swells to fill the wound, it must be possible to lift it straight out. With thought and creativity, the custom-made cavity product may be used in a range of difficult positions such as the ear, axilla and penis (Fletcher, 1999).