Wound management is a rapidly growing field, with new developments and discoveries coming one after the other. We’ve come a long way from the days where all wounds were managed with gauze (although gauze is still sometimes appropriate). What’s coming in the field of wound management? Let’s take a look at some of the “up and comers”.
Some of you may already be familiar with tissue adhesives if you work in emergency medicine. “Skin glues” are just what they sound like- specially formulated compounds that can be used to close a primary wound without the need for sutures or staples. Tissue adhesives are easy to apply, cause less pain for the patient and do not require a follow-up visit, thus they are extremely cost-effective. However, skin glues cannot be used on all wounds. The tensile strength of wounds is approximately 12 times less when the compound is applied, thus increasing the risk for wound dehiscence. Skin glues should not be used on wounds that overlay a joint as the risk of dehiscence is too great. They should also not be used on wounds that are heavily contaminated or on wounds where there is missing tissue. For best results, use on uncomplicated linear wounds located away from joints. Tissue adhesives are now widely available over the counter for use by the public.
Growth factors are substances that enhance cell activity, size or proliferation. Examples of growth factors include cytokines, colony-stimulating factors and interleukins. These substances have been isolated from healing wounds and are thought to aid in wound healing. In human studies, addition of these substances to wounds results in significantly improved wound healing, compared to wounds treated with placebo.
Regranex, a gel that contains platelet-derived growth factor (PDGF), has been studied extensively and has been found to enhance collagen deposition, stimulate the migration of fibroblasts and inflammatory cells into the wound and increase the formation of granulation tissue. Regranex has been approved for use on diabetic foot ulcers, providing the ulcer does not extend through the subcutaneous tissue.
Oasis is a dressing composed of freeze-dried small intestinal submucosa derived from pigs. This dressing contains growth factors and an acellular matrix of collagen. It has been used to facilitate healing in wounds that are partial-thickness, such as pressure ulcers, diabetic ulcers and venous insufficiency ulcers. The dressing is available in a dry form that is trimmed to the size of the wound and hydrated, and then covered with a moist compression dressing. Loose edges are trimmed when dressing changes are performed, and additional layers of Oasis can be added. Both Oasis and Regranex have shown promise for use in wounds that have stalled in healing. However, these products are extremely expensive and are typically reserved for wounds that are particularly difficult to manage. Further research will likely lead to other products containing growth factors, as well as an increased use of these products.
Skin Substitutes and Biosynthetic Dressings
Nothing is better than our skin at performing the functions of our skin, such as preventing water and heat loss, protein and electrolyte loss and prevention of infection, but biologic dressings and biosynthetic dressings are as close as we can currently get. These products are used to encourage autolysis and can help to create a healthy wound bed.
Type 1 bovine collagen has been incorporated into a variety of dressings and topical agents. These products provide a scaffolding for keratinocytes and the formation of granulation tissue. Collagen powders and pastes can be difficult to apply and require a secondary dressing. One advantage is that collagen dressings adhere to the wound bed but not to the periwound. Collagen dressings can be used on virtually any partial- or full-thickness wound. The high cost of these dressings is the biggest disadvantage to their use.
Skin grafts are often used to cover large wounds, burns and chronic wounds that have failed to heal using other methods. Unfortunately, they have many limitations. Allografts (derived from a cadaver) and xenografts (derived from an animal) are very expensive and have a very short shelf life. Individuals of certain cultures/religious beliefs may be against the use of products derived from animals or cadavers (or both). Autografts (derived from the healthy skin of the patient) lead to the creation of a large wound and may not be practical when the wound is extensive.
Skin substitutes can be used for extended wound coverage and can be used to achieve rapid closure of the skin. Skin substitutes consist of multiple layers that closely resemble the structure and function of the skin. They are used predominantly in burn clinics and centers and are very costly at the present time. Examples include Biobrane, Integra, and Alloderm.
The future of wound care is bright. Clinicians who work in wound management will likely see new and improved permutations of these specialized products as time goes on. For this reason, it is important for wound care practitioners to stay abreast of the latest news and products in the world of wound care management.
Meyers, B (2008). Wound Management: Principles and Practice. 2nd edition. Pearson Prentice Hall. Upper Saddle River, New Jersey. pg. 142-146.
Baranoski, S & Ayello, E. (2012). Wound dressings: An evolving art and science. Advances in Skin and Wound Care, February 2012, Volume 25 Number 2, p 87 – 92 http://www.nursingcenter.com/CEArticle?an=00129334-201202000-00010&Journal_ID=54015&Issue_ID=1293200