If a dressing is selected for solving a problem in the wound, it must be used for a long time so that the desired goal can be achieved, unless there are significant side effects. There are many types of dressing, mainly including alginate dressings, antibacterial dressings, foam dressings, honey, hydrocolloids, hydrophilic fibers, and hydrogels. Each dressing has different properties and indications and should be selected according to the specific condition of the patient and wounds.
1. The mechanisms of foam dressing
Different company products have different functions, but the main function is to absorb and lock the exudate, provide high absorption and prolong the service time. Foam dressings have pores of various sizes that can absorb exudates from the wound bed and lock them in place. Dressings usually have smooth surfaces and are hydrophilic. While some dressing products' surface have larger size of holes, which can absorb and lock debris and have the effect of micro-debridement.
Most foam dressings absorb exudates vertically, and we can see that the exudative imprint of the dressing after absorbing exudates is consistent with the shape of the wound. The purpose is to avoid maceration of the surrounding skin. Some foam dressing products absorb exudates laterally, that is, the exudate will spread throughout the foam after entering it, so the risk of maceration of the surrounding skin is greater. And some dressings combine the above two ways, namely the foam dressing is divided into different layers such as contact layer, absorption layer, and back layer, etc. It absorbs vertically with the wound contact layer, and can move to the side after entering the absorption layer, making full use of the absorption ability of the material. Because the absorption layer has a locking effect, the exudate will not overflow, so the risk of impregnation will not be increased.
Wound foam dressing can not only lock the exudate, but also can further increase its ability to manage the exudate because excess liquid will evaporate away from the semi-permeable backing. The absorption ability of each foam dressing has the limit, we should pay more attention to the surface of the dressing while using. When the exudate imprint is close to the edge of the dressing by 2 cm, it should be changed in time to avoid the leakage of exudates. Different manufacturers may use different methods to test products, so the parameters declared by manufacturers are not necessarily comparable, while experienced wound specialists have intuitive feelings and experience for different products after many years of personal practice.
2. Clinical indications for foam dressing
The role of foam dressing is for exudation management, therefore, it is mainly used in different degrees of exudative wounds. The absorption ability is different according to different product specifications and brands. The manufacturer will indicate the application range of the product on its packaging (mild to severe exudative wounds), doctors and nurses can choose the appropriate product according to the degree of wound exudation. Foam dressings like silicone foam dressing 4x4 should not be used on dry necrotic wounds or dry epithelial stage wounds. They can be used for a long time (up to 7 days) because of their excellent ability to absorb and manage exudates, but the frequency of replacement should be determined by the amount of wound exudation.
Wound foam dressings are usually used for superficial wounds, and special cavity products can also be used for cavity wounds with larger defects. There is no obvious limitation on wound types and it can be used in a variety of wounds including ulcer of lower limb (it can be combined with pressure therapy), pressure ulcers, traumatic wounds, ostomies and tracheostomies, slight burn wounds, skin grafts, donor sites, diabetic foot ulcers, and other exudative wounds.