Absorbent Hydrofiber And Calcium Alginate Foam Dressings
Hydrofiber dressings are made up of a substance that is very absorbent called sodium carboxymethylcellulose (CMC)
. When you go out to buy these dressings they will be available in either sheets or ropes.
Both, hydrophilic and hydrophobic properties are present in the material. This is in the carboxy and methylcellulose regions, respectively.
The CMC bounds the exudate to the center of the fiber and cannot be bioresorbable.
The way this works is that the glycoproteins is bound by the carboxymethylcellulose on cell surfaces. This lets absorption and sequestering of inflammatory cells especially the neutrophils. This helps in hastening the re-epithelialization.
The advantage of this kind of dressing is that it gives a moisture balanced milieu. This actually helps slow levels of autolysis and also controls to a very good extent the exudate as the dressing has a gelling property of the dressing, core.
In a study conducted of chronic venous ulcers on which CMC dressings was applied as compared to gauze showed that the use of CMC dressing was better. The chances of healing were 130% more and there was a chance of healing within 18 weeks. It also showed that there were reduced health care costs due to less need of nursing and physician costs that are part and parcel of dressing changes.
The Hydrofiber dressings are prescribed to people that have moderate to heavy exudates. These can also be used with a lot of surface bacterial burden.
However, these dressings are not preferred for dry wounds or wounds that have little exudate. The Hydrofiber dressings have good fiber strength and can be loosely packed into sinuses.
They are non-adhesive and need to have a tape or a secondary dressing to keep them in place.
Calcium alginate dressings on the other hand are made from kelp and composed of calcium alginate polysaccharides.
These dressings have the concept of a sodium-calcium ion exchange between the exudate from the wound and the dressing. This interaction of ion and the exudate produces a sodium alginate gel which has a moisture-retentive property and autolytic debridement potential. This makes these dressings a candidate for moderately draining wounds.
The physical properties of the dressing are determined by the varied composition of units of mannuronic and galuronic acid.
In addition to this increased concentrations of galuronic acid promote fiber strength and high levels of mannuronic acid encourage gelling. This helps in easier packing of the dressing for sale.