Question

1. What are four types of wound dressings? Describe the purpose of each.

2. What six factors affect selection of wound-dressing materials?

Answer 1

The four types of wound dressing-

1. Hydrocolloid dressing -

These dressings are made up of gel forming agents like sodium carboxymethylcellulose, gelatin, pectin and other materials like elastomers and adhesives. When the hydrocolloid comes in contact with the wound exduate it forms a gel and provides a moist environment that helps in protecting the granulating tissue.

The purpose or use of hydrocolloids are -

a) Useful in dry, flat wounds, cavities, sinuses, undermining wounds, medium to severe exduative wounds and paediatric wound care management.

2. Hydrogel dressing -

The hydrogels are insoluble hydrophilic materials made of synthetic polymers such as methacrylates and polyvinyl pyrrolidine. They posses 96% water content enabling them to donate water molecules to the wound surface and maintain a moist environment.

The purpose or use of hydrogels are-

a) Useful in dry chronic wounds, sloughy or necrotic wounds, surgical wounds, pressure ulcers,  burns and radiation dermatitis.

3. Alginate dressing -

These are made up of sodium and calcium salts comprising mannuronic acid or gluronic acid. The alginates form a gel like layer when it comes in contact with the wound exduate through the calcium/sodium ion exchange.

The purpose or use of alginates are -

a) It is useful in infected and non infected wounds with large amount of exduate, cavities and sinuses, and for undermining wounds.

4. Foam dressings -

They are made up of hydrophilic or hydrophobic foam like polyurethane or silicone foam.  The hydrophobic properties of outer layer protect from the liquid but allow gaseous exchange and water vapor. The foam consists of 2 to 3 layers, including a hydrophilic wound contact surface and a hydrophobic backing, making them highly absorbant.

The purpose or use of foam dressing are-

a) Foam dressing are suitable for lower leg ulcers, flat, shallow wounds and moderate to highly exduating wounds, also indicated for granulating wounds.

The six factors that affect selection of wound dressing materials -

The choice of wound dressing material depends upon - wound related issues, clinical effectiveness and economic factors.

1.Necrotic wounds -

Under ideal conditions, dead tissue in a wound will autolytically debride. However if dead tissue is exposed to a drying atmosphere it can dehydrate and shrink to form a eschar. Therefore the primary interevntion should be rehydrating the wound and removing hard, dead tissue.

Hydrogels , hydrocolloids and PMD's (Polymeric membrane dressing) are the choice of these wounds.

Examples - Granuflex, comfeel DuoDerm

2. Sloughy wounds/ Fibrinous wound

Slough is a complex mixture of fibrin, protiens, serous excudates, leucocytes and bacteria. It can build up rapidly on the surface of previously clean wound thus should be removed by swabbing or irrigation.

Protease lowering dressings, hydrogels, hydrocolloids are the choice of these wounds

Example - Promogram

3. Superficial disruptions of skin

Films and PMD's(polymeric membrane derssing) are the choice here

Examples -Tegaderm, blisterfilm

4. Exduative wounds

Alginates, hydrofibres, foams and PMD's are the choice here.

Examples - algiderm

5. Granulating/epithelializing wounds -

Hydrocolloids, hydrogels, PMD'S are the choice here

Examples - Douderm, NuDerm etc.

6.Colonized or infected wounds-

Silver iodide is the choice

Example- Silver containing dressings like Aquacel Ag/1