Wound contact layers an underutilized tool

Pass-through qualities protect wound bed

By Liza G. Ovington, PhD 

Program Director, Wounds and Continence 

Columbia Healthcare Corporation 

Fort Lauderdale, FL

There is a wide range of wound care products available when you want absorbency, but there also are times when you want to protect the wound bed with a nonabsorbent material. For this, there is a much smaller but highly useful category of products known as wound contact layers. 

These are transparent, nonadherent, nonabsorbent, perforated or apertured materials that are placed directly on the wound surface beneath an absorbent outer dressing. They are designed for use on a healthy wound bed and, in most cases, should not be placed on top of slough or necrotic tissue. 

The wound contact layer allows wound drainage to pass through, where it can then be absorbed by an absorbent product placed on top of the contact layer. A single wound contact layer can remain in place for multiple changes of the absorbent product. The primary purpose of a wound contact layer is to protect the wound bed and its delicate granular and epithelial tissues from being disturbed or traumatized during changes of the absorbent product. For example, many of the wound contact layers are designed to remain in place for up to seven days. 

Most of the wound contact layers are composed of polymeric materials (polyester, polyethylene, nylon, etc.) which are very thin and contain small perforations or apertures. These apertures are large enough to allow the passage of blood and serous fluids, but small enough not to allow the in-growth of epithelial or granular tissue buds. This feature prevents the contact layer from damaging the wound upon removal. The apertures also allow for the adjunctive use of topical creams or liquids (e.g. Silvadene, cream, antibiotic solutions) and simplify subsequent wound cleansing. 

The polymeric materials used for contact layers do not contain any adhesive coating that would adhere them to the wound bed or surrounding tissue but are meant to lay in the wound. Many of the products look similar to bridal veil netting. 

One particular brand of wound contact layer (Mepitel, SCA Molnlycke) is coated with medical grade silicon to enhance its nonadherent behavior. The silicon coating makes the product seem sticky and enhances its ability to conform to tissue contours and stay in place. However, it is not adhesive in the traditional sense. This particular wound contact layer has shown benefits in maintaining and protecting graft sites as they take.

Advisable to use contact layer when using gauze

Examples of absorbent products that can be used in conjunction with contact layers include foams, alginates, even gauze. In fact, if gauze is used as a wound dressing material, it is advisable to also use a wound contact layer. It is difficult to maintain a moist wound environment when using gauze alone as the absorbent product. Gauze has a tendency to dry out and stick to the wound bed, causing damage upon removal. A wound contact layer will not only prevent the gauze from adhering to the wound bed, but it will also promote a moist local environment. 

Examples of commercially available wound contact layers are shown in the table below.