Technical Guide APPLIED WOUND MANAGEMENT AND USING THE WOUND HEALING CONTINUUM IN PRACTICE David Gray, Richard White, Pam Cooper, Andrew Kingsley Assessing a patient with a wound involves accurate assessment of both the wound and the patient’s health status. The Applied Wound Management framework utilises three different continuums, each relating to a key wound parameter, the Wound Healing Continuum, the Wound Infection Continuum and the Wound Exudate Continuum. The Applied Wound Management The AWM system aids this type proceed effectively without (AWM) framework utilises of decision-making, reducing the a moist wound environment three different continuums, risk of poor practice and litigation. (Parnham, 2002). each relating to a key wound parameter: Using the Wound Healing Yellow and fibrous wound tissue 8 Wound Healing Continuum Continuum to assess tissue that adheres to the wound bed (WHC): is represented by the Wound tissue types and cannot be removed on tissues in the wound and is a If left to heal by secondary irrigation is known as slough colour-based continuum. intention, the tissues in a (Tong, 1999). This adherent, 8 Wound Infection Continuum wound (within the wound bed fibrous material is derived from (WIC): is subdivided into and margins) indicate the the proteins, fibrin and fibrinogen named stages representing relevant pathologies present, (Tong, 1999). In combination with varying host responses to reflect the state of healing and, wound exudate, it serves as an bioburden, each identified by consequently, the success of the ideal environment for bacterial clinical cues. management approach. Thus, growth and, consequently, 8 Wound Exudate Continuum a black wound (as opposed to infection (Davies, 2004). It also (WEC): is represented by black skin changes in melanoma, impairs healing by restricting volume and consistency gangrene or frostbite) indicates re-epithelialisation (Kubo et al, parameters, and each can be the presence of eschar or 2001). The clinical objective of graded according to a ‘matrix’ necrosis (Bale, 1997). Wound managing a sloughy wound is continuum. eschar is full-thickness, dry, to debride (Tong, 1999; devitalised (dead) tissue that has Hampton, 2005). This practical application to arisen through prolonged local everyday wound care enables ischaemia. In relation to pressure The red, moist tissue in a wound the practitioner to approach ulcers, eschar might arise after is a combination of new blood wound assessment logically a sudden large vessel occlusion vessel growth (angiogenesis), and and systematically. Increased caused by shearing injury a matrix of fibroblasts (connective workloads across the NHS (Witkowski and Parish, 1982). tissue or dermal cells), known as require decision-making to be Unless removed, the eschar will granulation tissue. This is usually systematic, clear and coherent. delay healing, as healing cannot indicative of a healing wound and Wound Essentials • Volume 5 • 2010 131 Technical Guide which disrupt the proteins that bind the dead tissue to the body (Schultz et al, 2003). The process can be enhanced by the application of wound management products which promote a moist BLACK BLACK/YELLOW YELLOW YELLOW/RED RED RED/PINK PINK environment. These products can 6 5 4 3 2 1 0 be divided into two categories: Figure 1. The Wound Healing Continuum. those that donate moisture to is often accompanied by signs Society [ETRS], 2003). The types of the dead tissue, and those that of re-epithelialisation (epidermal treatment available can be divided absorb excess moisture produced regrowth) (Gray et al, 2003). It is into three separate categories: by the body. Both are designed important to remember that not all 8 Active to facilitate the autolytic red wounds are healthy; they may 8 Autolytic (moisture donation). debridement process. be critically colonised and non- 8 Autolytic (moisture absorption). healing/static, or show evidence of Clinical use of debridement haemolytic bacteria (if a dull brick- Active debridement techniques red colour) (Dowsett et al, 2004). 8 Surgical debridement: this Treatments from more than one involves removing the dead group may be required to achieve The approach taken in the tissue from the wound bed. full debridement of the wound. Wound Healing Continuum is to It is usually carried out under The heel pressure ulcer presented incorporate intermediate colour surgical conditions and results in Figure 2 shows necrotic tissue combinations between the four in a bleeding wound bed. which has been rehydrated using key colours (Figure 1). To use this It removes dead tissue and an autolytic (moisture-donating) system to the optimum clinical results in an inflammatory treatment. This results in necrotic benefit, it is first important to response from the wound, thus eschar lifting at the wound margins identify the colour that is furthest stimulating healing (Bale, 1997) and separating from the slough to the left of the continuum. 8 Sharp debridement: this below. The necrotic tissue is For example, if the wound technique involves debulking the categorised as ‘black’ on the contains yellow slough and wound of slough and necrotic Wound Healing Continuum. red granulation tissue, it would tissue. This process requires be defined as a ‘yellow/red the use of surgical instruments, In Figure 3, the wound has been wound’. A key objective of the such as a specialist wound subjected to sharp debridement consequent wound management debridement pack and the necrotic tissue removed to plan would be to remove the 8 Larval therapy: the larvae liquefy leave the slough below exposed. yellow tissue and promote the the dead tissue and, where The wound is now categorised growth of red granulation tissue the treatment is successful, as a ‘yellow’ wound on the (Gray et al, 2005). can result in rapid debridement Wound Healing Continuum. No (Thomas et al, 1998). bleeding or pain has been caused. Identifying and obtaining Following sharp debridement, the treatment objectives Autolytic debridement patient is treated with a moisture- Debridement Autolytic debridement is the donating product (eg. hydrogel) to Where the wound exhibits removal of devitalised tissue from continue the process of autolytic dead tissue, eg. black, black/ the wound by means of the body’s debridement. yellow, yellow, or yellow/red, a own enzymes operating in a key treatment aim should be the moist environment. Where tissue The wound in Figure 4 is producing debridement of the devitalised can be kept moist it will naturally high levels of moisture which need tissue, unless contraindicated degrade and deslough from the to be absorbed. The wound bed by the patient’s overall physical underlying healthy structures. This is covered with slough which condition or disease process, such process is facilitated by enzymes requires debriding. The wound as PVD (European Tissue Repair (matrix metalloproteinases) is categorised as a ‘yellow/red’ 132 Wound Essentials • Volume 5 • 2010 Technical Guide categorised as ‘red’ or ‘red/ pink’, the main objective is the promotion of granulation tissue and then epithelialisation. Granulation (red) and epithelial (pink) tissue are the final two stages of the Wound Healing Continuum. Active treatment Topical negative pressure therapy (VAC® – vacuum assisted closure) Figure 2. Black wound. is used in the management of large granulating wounds, particularly cavity wounds. A foam pad is placed into the wound, which is then sealed and negative pressure applied via a vacuum pump. This facilitates the promotion of granulation tissue as well as removing excess exudate (Moore, 2005). Moisture donation Figure 3. Black/yellow wound post sharp debridement. The fragile nature of granulation tissue means that it has to be kept moist to prevent desiccation and delayed tissue growth. Products such as hydrocolloids, hydrogels and honey, can all deliver moisture to the wound bed, thus supporting granulation. Hydrocolloids, sheet hydrogels and sheet honey dressings can also provide an element of moisture absorption (Cooper, et al, 2003), but this is not their main function which is that of moisture donation. Moisture absorption An excess of moisture on the wound bed can lead to Figure 4. Yellow/red wound. maceration of the wound margins and delayed healing (Cameron and Powell, 1992). Alginates, cadexomer iodine, collagen wound on the Wound Healing stage of the Healing Continuum — products, foams and Hydrofiber®) Continuum. By utilising an autolytic ‘red’ (Figure 5). absorb exudate, providing (moisture-absorption) treatment, the ideal environment for the the wound is successfully debrided Granulation and epithelialisation promotion of granulation tissue and has moved on to the next Where a wound has been and epithelialisation of the wound. 134 Wound Essentials • Volume 5 • 2010 Technical Guide Promotion of granulation and epithelial tissue in clinical practice In Figure 6, the patient has presented with an abrasion to the knee. The wound is categorised as ‘red’ on the Wound Healing Continuum. Depending on the outcome of the assessment, the correct product selection will lead to a ‘pink’ wound as seen in Figure 7. Using the Wound Infection Continuum to assess bioburden While all chronic wounds left to heal by secondary intention will contain bacteria throughout, it is the delicate balance between the host (immune) response and the Figure 5. Red wound. pathogen that must be managed if infection is to be avoided (Casadevall and Pirofski, 2000). The mere presence of colonising bacteria in a chronic wound is usually