Hydrocolloid dressings give good adherence

By Liza G. Ovington

Program Director

Wound and Continence Management

Home Health Care Division, Southeast Florida

Columbia Healthcare Corp.

Fort Lauderdale, FL

(Editor’s note: This is another in a continuing series on the dressings used in wound care.)

Transparent films were the first type of dressings commercialized for creation of a moist wound healing environment. A major shortcoming of the films was, and is, their inability to manage wound exudate. The hydrocolloids were among the first categories of advanced dressings to address the need for absorbency.

The history of hydrocolloid dressings for wound care has its origins in ostomy care. A precursor to hydrocolloid dressings called Stomahesive was marketed by E.R. Squibb to ostomy patients for protection of the skin around the stoma site. Stoma nurses started making subjective observations about the condition of the skin beneath the Stomahesive. In particular, they noted that irritated or excoriated peri-stoma skin appeared to heal beneath the Stomahesive product. In addition, ostomy patients began to write to Squibb to say what a difference this product was making in their lives. These observations and comments sparked a commercial interest in adapting the Stomahesive material for use on wounds.

That initial interest culminated in the launch of a hydrocolloid wound dressing in the early 1980s by the ConvaTec division of E.R. Squibb. Other hydrocolloids soon joined the market and this particular category of advanced wound dressings is one of the most broadly used today. They are able to manage moderate amounts of wound exudate and are characterized by their almost unparalleled ability to adhere in a variety of conditions and anatomical locations.

The target: Chronic wounds

Hydrocolloids are composed of a mixture of adhesive, absorbent, and elastomeric ingredients. Carboxymethyl cellulose is the most common absorptive ingredient. Some hydrocolloids contain pectin. All the hydrocolloids are specifically indicated for chronic wound management and have also been used in burn treatment.

The hydrocolloids usually require no secondary dressing due to their inherent adhesive components which give them an initial adhesion higher than that of some surgical tapes. They create a moist healing environment, but unlike most other dressings, are impermeable to moisture vapor and gases.

A unique and perhaps controversial feature of the hydrocolloids is their "melting" behavior. As the hydrocolloid dressing absorbs exudate, it forms a viscous, colloidal gel that will remain in the wound upon removal of the dressings. This gel can usually be removed via saline irrigation without damage to the wound. However, an inexperienced clinician may mistake the colloid gel in the wound for purulent discharge due to its color, consistency, and odor. A hydrocolloid does possess a faint "chemical" odor (smell one the next time you open it) and this odor grows stronger when the material melts. Due to this confusion, many hydrocolloids have now been reformulated to not melt at all or to a much lesser extent than those first on the market in the early 1980s. (For a list of hydrocolloids used today, see chart below.)

Hydrocolloids are available in traditional-thickness versions and extra-thin versions. The extra-thin hydrocolloids are uniquely conformable and adhesive. Some brands of hydrocolloids contain a percentage of alginate material to supposedly boost their absorbent capacity. Certain brands of hydrocolloids are bordered with a foam or film adhesive edge and some have beveled edges. Some manufacturers offer their hydrocolloids in a variety of pre-cut shapes aimed at different anatomical sites. There are flower shapes for knees, elbows, and heels, triangular shapes for the sacrum, and small round "spots" for biopsy sites and small wounds.

Good skin adhesion

The outstanding feature of the hydrocolloids is their ability to adhere to skin, be it dry or moist. They do not adhere to the moist wound bed, however, due to their melting behavior. The hydrocolloid material will melt to varying degrees (depending on the brand) when it is in contact with a source of continuous moisture loss, such as an open wound. Certain brands of hydrocolloids do not melt, but swell. The hydrocolloids have a moderate absorbent capacity. Depending on the wound drainage, they may be left in place for three to four days. In general, a clinician will choose a hydrocolloid when the biggest challenge in managing a wound is adhesion or when an extended wear time is desired. The extra-thin hydrocolloids are exceptionally suited for maximum adhesion due to their thin profile and consequent conformability.

Because of their composition, even the edges of a hydrocolloid dressing are adhesive. This can be a problem if the dressing adheres not only to the patient but to the patient’s bedding and clothing, causing it to roll off the wound. The bordered hydrocolloids and bevel-edged hydrocolloids were designed with this in mind. Often, clinicians will border a hydrocolloid with tape to prevent the edge roll-up problem.

In the past, clinicians have complained of the tenacity of hydrocolloid adhesion to the peri-wound skin or of the difficulty of removing melted hydrocolloid from the wound bed. For the most part, this problem was most prevalent in the earlier versions of hydrocolloid material and has been corrected in new formulations.

A helpful hint

Hydrocolloids adhere most efficiently when they are at body temperature. When applying a hydrocolloid dressing to a patient, it is helpful to place a hand over the dressing surface to facilitate its reaching body temperature.