The Online Newsletter for Children's Nurses
e-Edition, Issue 9
Optimizing the Wound Healing EnvironmentBy Gloria Liu, MSA, RN, CWOCN
There are three principles in topical wound management. One is to control or to eliminate the causative factors, such as offloading pressure or protecting the skin from excessive moisture. Another is to provide systemic support to reduce existing and potential contributing factors. Examples of this might be optimizing nutrition or promoting adequate oxygenation. The last principle is to maintain an optimal local wound environment.
The ideal wound environment to promote healing is one that 1) is rid of necrotic tissue, bioburden and foreign debris, 2) is free of and protected from infection, 3) has no dead space, 4) is insulated from local hypothermia, and finally 5) has a balanced moist wound bed. Strategies to promote healing are many and require a partnership between the physicians and the nurses to establish the plan of care. This article will discuss various types of interventions and their use.
Necrotic tissue in the wound can be removed by conservative instrumental debridement done at the bedside, or surgical debridement performed in the operating room. Autolysis and chemical debridement are utilized for smaller wounds that do not post immediate morbidity or if the patient is not a suitable candidate to receive sharp debridement. In autolytic debridement, a moisture retentive dressing such as hydrocolloid (e.g., Duoderm) or hydrogel (e.g., Carrasyn amorphous hydrogel) is applied to rehydrate and to promote the breakdown of the necrotic tissue. Collagenase Santyl ointment and moisture retentive dressings are employed in chemical debridement. Be aware that the solubilization of the necrotic tissue and the melt down of the hydrocolloid dressing can resemble infected wound exudates. A thorough wound irrigation with each dressing change is essential to ascertain an accurate assessment. When a wound has a large amount of slough and odor, dressing it with gauze saturated with diluted Dakin’s solution can be very effective. Currently, there are no published studies demonstrating the efficacy of utilizing wet-to-dry gauze as a method of debridement. When the moisture in the gauze evaporates, it leads to a drop in the wound temperature causing increased wound tissue metabolism and decreases pH. Removal of dried gauze can cause bleeding, disruption of granulation and pain. Wet-to-dry dressing is probably acceptable when the wound is heavily necrotic or infected without visible granulation tissue. Other known debridement methods are pulsatile lavage, ultrasonic mist, hydrotherapy, and biosurgical therapy, which utilizes sterile maggots. Dry and firm eschar on heels and toes without periwound inflammation needs no debridement, but requires daily inspection.
When a wound exhibits signs of heavy bioburden or local infection, topical antibiotic (e.g., Bacitracin) or an antimicrobial dressing (e.g., Aquacel Ag) can be utilized. Systemic antibiotic(s) will be necessary if there is cellulitis. A thorough wound irrigation using a warm physiologic solution or commercial non-cytotoxic wound cleanser under 4-15 psi will remove loose debris and lessen the amount of bioburden. Covering a wound with an occlusive or semi-occlusive dressing, along with less frequent dressing changes will protect the wound from outside contaminant, trauma and cold stress. Maintaining a normal wound bed temperature will prevent wound vasoconstriction and hypoxia and will decrease the risk of infection.
A wound with dead space, i.e., depth, tunneling or undermining, requires a wound filler to minimize accumulation of exudate and abscess formation. Dead space with a small amount of depth can be dressed with calcium alginate or amorphous hydrogel, whereas one that is deep may require packing agents such as gauze strips.
The concept of keeping the nonsurgically closed wounds moist and protected is not new. There is documentation indicating that the ancient Mesopotamians dressed their wounds with fine linen soaked in oil. The Greeks applied animal fat and wrapped the wounds, and the Roman applied ashes, oil and herbs and wrapped the wounds. In 1927, Dr. Helmut Schmidt, from Germany, started to use cellophane, which was semi-occlusive, as a bandaging material. He and a handful of other German physicians were able to show that using cellophane rather than standard bandages cut down on infections and sped healing. In 1939, an American, Dr. E.L. Howes, published the first article, “Cellophane as a Wound Dressing,” in the medical journal, Surgery.
George Winter, in 1962, published the first controlled study describing how the occluded wounds epithelialized faster than those that were exposed to air. Since then, multiple controlled studies have established that a moist wound environment could facilitate cellular growth and collagen proliferation. Dry wound tissue is more prone to infection, scarring, delayed healing and pain. However, excessive moisture in the wound bed can impair the healing process and also cause periwound maceration.
There are a multitude of wound care dressings in the market today. Most dressings are known as moisture-retentive dressings, which are occlusive or semi-occlusive. Different dressings may be necessary throughout various phases of healing. Primary dressing is what is applied directly to the wound bed. Secondary dressing is used as an adjunct to augment the therapeutic function of the primary dressing or is used to secure the primary dressing. Skin surrounding the wound needs to be protected from wound drainage and adhesive stripping by using a skin barrier product (e.g., Cavilon No Sting Barrier film).
Assess the amount of wound drainage and depth of the wound in order to determine the appropriate dressing. Transparent film dressings such as Tegaderm are suitable for shallow partial thickness wounds with minimal exudates; otherwise, they are often utilized as secondary dressings. Hydrocolloid dressings provide a moist healing environment that allows clean wounds to granulate and necrotic wounds to debride autolytically. Hydrocolloid dressings come in different thicknesses and can be used as either a primary or secondary dressing. Thin hydrocolloic dressings have a low absorbent capacity, and all hydrocolloid dressings have fairly aggressive adhesive contact layer, which can cause epidermal stripping upon removal. Thin silicon foam dressings such as Mepilex Lite are much kinder to the wound and surrounding skin. Calcium alignate (e.g., Tegaderm alginate), hydrofiber (e.g., Aquacel), or foam dressing (e.g., Mepilex) are suitable for exudating wounds. The frequency of dressing changes is dependent upon the manufacturer’s recommendation, the amount of drainage and whether there are signs of infection. The dressing should also be changed when there is strike-through, leakage, separation or soilage.
There are many factors influencing wound healing. There are no absolutes on the type of dressing that should be used. The most effective dressing is one that provides a protected and moist environment for the wound to heal, does not require frequent changing and provides patient comfort.
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Bryant, R. & Nix, D. (2012). Acute & Chronic Wounds: Current Management Concepts. 4th ed. Mosby.
Dale, B. et al. (2011). Say goodbye to wet-to-dry wound care dressings: changing the culture of wound care management within your agency. Home Healthcare Nurse, 29(7): 429-440.
Eaglstein, W. (2001). Moist wound healing with occlusive dressings: a clinical focus. Dermatologic Surgery, 27(2): 175-181.
Majno, G. (1975). The Healing Hand; Man and Wound in the Ancient World. Harvard University Press.
National Institute for Health and Clinical Excellence. (2008). Surgical site infection: Prevention and treatment of surgical site infection. NICE clinical guideline 74. www.nice.org.uk.
Okan, D, et. al. (2007). The role of moisture balance in wound healing. Advances in Skin and Wound Care. 20(1): 39-53.
Root-Bernstein, R & Root-Bernstein, M. (1997). Honey, Mud, Maggots and Other Medical Marvels. Houghton Mifflin Company.
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In This Issue
A Recipe for Advanced Clinical Systems
Code of Ethics for Nurses
Champions… A Key to Success
Optimizing the Wound Healing Environment
The Pace of Regulatory Change
Alphabet Soup in the Ambulatory Division
Shared Governance: PICU Skin Care Program
Striving for Excellence in Children's Asthma Care
Patient Satisfaction Comments