Hydrocolloid dressings consist of absorptive ingredients (typically carboxymethylcellulose, pectin, or gelatin). Like hydrogels, hydrocolloids can absorb minimal to moderate amounts of drainage. They can be used for partial- or full-thickness acute and chronic wounds. Some sheet hydrocolloids are opaque, making wound assessment difficult; others are translucent or transparent.

Because they are occlusive, hydrocolloid dressings do not allow water, oxygen, or bacteria into the wound. This may help facilitate angiogenesis and granulation. Hydrocolloids also cause the pH of the wound surface to drop; the acidic environment can inhibit bacteria growth.

Like hydrogels, hydrocolloids can help a clean wound to granulate or epithelialize and encourage autolytic debridement in wounds with necrotic tissue. However, because of their occlusive nature, hydrocolloids cannot be used if the wound or surrounding skin is infected.

Types of Hydrocolloids

Three types of hydrocolloids are available: pastes, powders, and sheets.

Hydrocolloid pastes generally come in tubes, and hydrocolloid powders come in packets. They can be used as wound fillers, but they should not protrude above the level of the surrounding skin. A secondary dressing, such as a hydrocolloid sheet dressing, is needed to cover hydrocolloid pastes and powders.

Hydrocolloid sheet dressings are available in various thicknesses and in precut shapes for body areas such as the sacrum, elbows, and heels. Highly conformable to the patient's body these dressings adhere well to high-friction areas, such as the sacrum and heels. All sheet hydrocolloid dressings have a film covering to make the product waterproof.

Hydrocolloid dressings react with wound drainage and swell or "melt out,leaving a residue in the wound. When the dressing is removed, a gel residue may be left in the wound bed. (The paste and powder forms typically leave a residue"plug"in the center of the wound.) Remove this residue by cleaning gently with a wound cleanser before assessing the wound. A distinctive foul odor may also be present. This may be from product breakdown, not infection.

Hydrocolloids in Practice

The Stage III pressure ulcer of the left buttock shown in Figure 1 has a granular base and a small amount of exposed subcutaneous tissue. The treatment goal is to maintain wound hydration. The wound cavity should be filled with a hydrocolloid paste and covered with a hydrocolloid sheet dressing.

Figure 2 shows a partial-thickness wound to the lateral aspect of the left lower leg. This wound is clean, healthy, and granulating, with a scant amount of serous drainage. The treatment goal is to maintain a moist wound environment. The best topical wound management product choice for this wound is a hydrocolloid sheet dressing.

The pressure ulcers of the left and right heels shown in Figure 3 are covered with 2 types of necrotic tissue-Slough and eschar. The wounds are not infected and are draining a scant amount of serous fluid. A hydrocolloid can be used to autolytically debride these wounds.

Hydrocolloid Hints

The following points should assist in use of hydrocolloids:

Hydrocolloids adhere best at body temperature. To promote adherence, the clinician should place his or her hand over the dressing after applying it to the wound. The heat from the clinician's hand will assist in molding the dressing to the wound and facilitating adherence.

Hydrocolloid dressings with thick edges may "roll up" and adhere to the patient's clothing or bed linens, decreasing the dressing's wear time. Dressings with thinner, tapered edges generally adhere better to the periwound skin without rolling up.