GauzeWoven or non-woven fabric produced from cotton, viscose, polyester, or other suitable fibres formed into a swab. Should not be used as a primary dressing as it adheres strongly to wound bed due to capillary looping into the structure.
Contact layersIncludes simple products such as paraffin gauze (tulle gras) (cotton or cotton and viscose woven fabric, which has been impregnated with white soft paraffin) and knitted viscose dressings. More advanced products such as silicone-coated net dressings and hydrocolloid or gel-impregnated viscose nets are now generally preferred. Contact layers have no absorbent properties and generally require a secondary absorbent layer.
Wound dressing padsThe basic wound dressing pad consists of an absorbent layer such as cellulose fibre enclosed in a sleeve of a nonwoven fabric. Some pads have a perforated plastic film layer to reduce adherence to the wound surface – e.g. Melolin, Smith & Nephew Healthcare Ltd.
Semi-permeable film dressingsConsist of a transparent polyurethane film coated with a thin layer of adhesive to enable the dressing to adhere to intact skin but not the wound surface. These dressings are permeable to moisture vapour and gases but impermeable to water and microorganisms.
Hydrocolloid dressingsThese dressings comprise an absorbent gel-forming mass, commonly consisting of carboxymethylcellulose, which is contained within their structure together with elastomers and adhesives. The dressings are usually presented in the form of a self-adhesive wafer that absorbs wound exudate and traps it in the form of a gel. Hydrocolloid colloid dressings are generally occlusive in their intact state but become semipermeable once in contact with wound fluid.
HydrogelsThese consist of hydrophilic polymer commonly made from carboxymethylcellulose or modified starch dissolved or dispersed in water or a mixture of water (80%) and propylene glycol (20%) as a humectant and preservative. They have the ability to absorb exudate or rehydrate slough or necrotic tissue in a wound depending on whether the wound is exuding heavily or dry and necrotic – for example Intrasite®, Smith & Nephew Healthcare Ltd.
Alginate dressingsThese are derived from seaweed, usually prepared as the calcium salt of alginic acid. When in contact with serum, wound exudate or solutions containing sodium ions, the insoluble calcium alginate is partially converted to the soluble sodium salt, and a hydrophilic gel is produced.
Foam dressingsMost foam dressings are designed to absorb and retain fluid. Modern foams are available in a variety of formats (shaped, adhesive, non-adhesive, bordered, cavity) with varying levels of absorbency and permeability.
CMC fibrous dressingA primary wound dressing made from sodium carboxymethylcellulose fibres woven into a fleece similar in appearance to the alginates.
Capillary dressingA three-layer, non-woven/woven, low-adherent dressing, which comprises 100% polyester filament outer layers and 65%/35% poly/cotton fibres.

From: 6, Evidence reviews with guideline recommendations

Cover of The Management of Pressure Ulcers in Primary and Secondary Care
The Management of Pressure Ulcers in Primary and Secondary Care: A Clinical Practice Guideline [Internet].
NICE Clinical Guidelines, No. 29.
Royal College of Nursing (UK).
London: Royal College of Nursing (UK); 2005 Sep 22.
Copyright © 2005, Royal College of Nursing.

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