Dressing techniques

Wound dressings serve to reduce pain, protect the wound from further injury and infection, and reduce moisture loss. Dressings should be nonadherent, sterile, and cover the wound completely. Adherent dressings delay wound healing. When dressings are applied to wounds, an aseptic technique must be used.

Bio-occlusive dressings

These allow air and water vapour to permeate, thus accelerating healing; they are transparent to allow wound assessment and are waterproof.

Calcium alginate

Calcium exchanges with sodium from the wound to convert exudates to a gel. This reduces moisture loss. They are not effective for dry wounds since they depend on absorption of exudates to be active.

Foam dressing

Foam dressings absorb excessive exudates while allowing air and vapour permeation to accelerate healing. They require absorption of exudates to be effective. They are thermally insulating and non-adherent.

Hydrocolloids

Hydrocolloid dressings provide slow absorption of exudates to create a soft, non-adherent gel which occludes the wound and retains moisture. They are effective when exudates are low volume. They should not be used in infected wounds as growth of anaerobes may be encouraged by their occlusive properties.

Hydrogels

Hydrogels have hydrophilic sites to enable absorption of excess exudates. They retain moisture.

Vacuum-assisted closure (VAC)

A foam dressing is placed in the ulcer absorbing excessive exudates. The ulcer is sealed with an adhesive drape and negative pressure is applied for up to 24h per day. The VAC dressing reduces oedema and improves local blood supply while removing surface debris and exudate. Intermittent treatment may be more effective than continuous. Use of VAC dressing is advantageous in perineal pressure sores because the vacuum helps keep the dressing in place.

Properties of wound dressings

• Maintain warmth.

• Maintain moisture.

• Remove exudates.

• Allow vapour and gas permeation.

• Minimise contamination.

• Non-adherent.