Key learning points
- Wound causes and special considerations for these different types
- Assessment and dressings
- Encouraging effective healing at different stages
The process of tissue repair or healing is extremely complex and unpredictable, particularly in older patients suffering from multiple co-morbidities and with the effects of aging on the tissues. In all cases, healing will rely on the controlled response to trauma and the intrinsic ability of the body to heal. Every patient´s healing needs and wound are unique, which will present ever-changing challenges to the clinician. Guest et al (2015)1 estimated the annual NHS cost of managing wounds to be £4.5-£5.1bn, after adjustment for comorbidities, with two-thirds of the cost incurred in the community and the rest in secondary care (2013/14 prices). The same study estimated that 2.2 million wounds were managed by the NHS in 2012/2013 and highlighted the excessive amount and cost of nursing time involved, the pressure is on to ensure that wound management is as effective as possible.2
This article will briefly explore common chronic wound types, their aetiology and, where relevant, evidence-based management.
In the main, intentionally created, acute surgical wounds and simple lacerations will heal without a problem in an otherwise healthy person. Acute wounds are expected to heal within an anticipated timeframe with no patient or environmental factors delaying healing.3 Minimal or no tissue loss allows clean, acute wounds to rapidly seal and heal through a complicated process that is not yet fully understood, especially in terms of why some patients heal efficiently and others take extended times or do not heal.
The commonly encountered problematic wounds are those that become chronic. These include leg ulcers, pressure ulcers, diabetic foot ulcers, dehisced wounds and any wound that is being left to heal by secondary intention. Such wounds can be identified as chronic if the underlying aetiology is diagnosed. This is essential to developing a successful care plan for optimising the patient´s ability to achieve healing, as much as possible.
To enable high quality and effective wound management the assessment must properly reflect the wound characteristics. It must also be current, as wound characteristics can change rapidly. It must be comprehensive, to ensure nothing important is missed.
After obtaining a full patient and wound history, the next phase is to ascertain the phase of healing.
The wound may be newly formed and still be showing characteristics of the inflammatory phase (redness, heat, pain and swelling),4 which may be confused with signs of infection if the duration of the wound is not considered. The proliferative phase is characterised by the formation of fragile granulation tissue, which is easily traumatised by inappropriate handling or dressings, as is the new epithelial tissue in the maturation or re-modelling phase. Knowledge of the phases of healing is vital to ensure that the principles of wound healing are followed.
The basic wound assessment parameters include:
• The wound type, size, location, tissue type.
• Presence of exudate.
• Symptoms such as pain, inflammation, odour.
• Wound edges and assessment of the surrounding skin for excoriation or maceration.5
No definitive, agreed published guidance exists on the management strategies for individual types of chronic wounds, despite the publication of numerous pressure ulcer and leg ulcer guidelines, a debridement systematic review and consensus statements. Modern wound care products and therapies are founded on the concept of moist wound healing since Winter’s6 work demonstrated that epithelialisation proceeds twice as fast in a moist environment than under a scab. Since this time, we have seen the development and effective use of dressings and therapies that provide the desired moist, warm, clean environment. Additional benefits include reduction in pain and efficient management of exudate.
A practical, colour classification has been suggested for identifying the phase of healing and guiding wound assessment and intervention.7 This, together with various wound staging systems (eg the European Pressure Ulcer Advisory Panel classification for pressure ulcers, or Skin Tear Audit Research [STAR] classification for skin tears), assists in the choice of dressings and therapies.
Types of wounds
Black necrotic (eschar)
- The tissue in the wound is dead and presents as dry, leathery material from the destruction of cells and blood vessels, which may completely cover the wound and make assessment impossible.
- Aim of management: to rehydrate the tissue, stimulate autolysis and prevent infection.
- Dressings: the most commonly used is the amorphous or hydrogel dressing together with a semi-permeable secondary dressing, which is designed to release moisture to soften and ‘dissolve’ dead tissue. Alternatively, hydrocolloid dressings are also designed to create a warm, clean, moist environment in which autolysis will occur, and protect the wound. Autolysis relies on the inherent ability of the body through its enzymes, immune system and moisture to liquefy and eliminate necrotic and sloughy tissue. It is painless and only necrotic tissue or slough is liquefied when appropriate dressings are used; however, it can take a long time and may cause maceration of the wound and wound edges. Alternatively, the wound may be debrided surgically by a suitably qualified clinician, if this can be tolerated.
- The wound is covered or partially covered in soft, moist, dead tissue, mainly yellow in colour but possibly ranging from white through to dark grey or brown. This tissue is composed of dead cells accumulated in exudate and should be removed to reduce the risk of infection.
- The exudate levels must be accurately assessed before choosing the most suitable product.
- Aim of management: to de-slough, prevent infection.
- Dressings: after determining the exudate levels, hydrogel or hydrocolloid dressings to encourage autolysis should be used.
- The wound must be monitored for signs of infection and managed with dressings containing honey (eg Activon) or silver (eg Aquacel AG, Acticoat), and a decision made as to whether systemic antibiotics are required if there is a host response to the wound infection.
- Alternative methods may include larval therapy (biological debridement), in which sterilised maggots (available on prescription) work quickly and selectively to digest necrotic material by secreting bactericidal enzymes. Larval therapy has been demonstrated to be effective against methicillin-resistant Staphylococcus aureus and beta-haemolytic streptococcus. Although larval therapy has been widely practised throughout the UK for almost 20 years, it does make many feel squeamish. Debrisoft, as endorsed by the National Institute for Health and Clinical Excellence (NICE),8 is a more recent innovation. It is a pad made of soft, polyester fibres secured and knitted together and cut at a special angle, length and thickness to effectively cleanse and debride skin and the wound bed. The product is quick and simple to use and is effective on acute wounds such as gravel rash and for mechanically removing slough from chronic wounds prior to assessment. The European Wound Management Association has published useful guidance on debridement.9
- This indicates a confirmed infection with host response, classic signs of inflammation plus the extended criteria of tracking, bridging and excess exudate.10
- Aim of management: control infection and achieve healing.
- Dressings: anti-microbials, silver-containing or honey dressings, dressings containing polyhexamethylene biguanide hydrochloride (PHMB), topical negative pressure (TNP) therapy, larval therapy; antibiotics if clinically indicated.
- Granulation tissue consists of fine, tiny, fragile capillaries growing in an extracellular matrix.
- Aim of management: protection and support for healing.
- Dressings: assessment of the wound depth, extent and exudate level. All dressings must minimise the risk of trauma to the wound, eg non-adherent dressings for flat wounds. Foam dressings, cavity fillers, fibrous and alginate dressings (absorbent or non-absorbent) may be used depending on exudate level.11 TNP therapy can be cost-effective, efficacious and convenient, and is well accepted by patients and clinicians despite limited scientific proof of its usefulness. Many newer variations on the original foam dressing have been introduced, for example, an irrigation facility and specialised abdominal dressings. A recent mini-review highlights some of the infrequently encountered complications of TNP.12
- Re-epithelialisation occurs with the migration of cells from the periphery of the wound and exudate levels are very low. The new skin is fragile.
- Aim of management: the same rules apply as for managing granulation wounds.
- A cover of semi-permeable film or thin hydrocolloid is recommended and left in place until re-epithelialisation is complete.
Few wounds will fall into a single colour classification; many will be a mixture of several colours at the same time. The clinician must decide the aims of treatment and priorities at each wound assessment and dressing change.
Up-to-date information about wounds and the range of management options is available from national and international bodies such as NICE, the European Wound Management Association (EWMA), the European Pressure Ulcer Advisory Panel (EPUAP), the Tissue Viability Society (TVS), the Wound Care Alliance (WCA) and the World Union of Wound Healing Societies (WUWHS).
Position documents, anecdotal reports and personal experience are all useful guides to the development of good practice in wound care.
Wound care companies are also excellent sources of clinical data and information about individual dressings and therapies.
1 Guest J, Ayoub N, McIlwraith J et al. Health economic burden that wounds impose on the National Health Service in the UK. BMJ Open 2015;5:e009283. bmjopen.bmj.com/content/5/12/e009283 (accessed May 2017).
2 Posnett J, Franks P. The costs of skin breakdown and ulceration in the UK. In: Skin Breakdown. The Silent Epidemic. Smith & Nephew Foundation 2007.
3 Benbow M. Modern wound therapies. Journal of Community Nursing 2007;22:20-8.
4 Hart J. Inflammation 2: its role in the healing of chronic wounds. Journal of Wound Care 2002;11:245-9.
5 Mahoney K. Understanding the basics of wound care in the community setting. Journal of Community Nursing 2014;28:66-75.
6 Winter G. Formation of the scab and the rate of epithelisation of superficial wounds in the skin of the young domestic pig. Nature 1962;193:293-4.
7 Cuzzell J. Wound healing: translating theory into clinical practice. Dermatology Nursing / Dermatology Nurses’ Association 1995;7:127-31.
8 National Institute for Health and Care Excellence. The Debrisoft monofilament debridement pad for use in acute or chronic wounds. London: NICE; 2014. Available at: guidance.nice.org.uk/mtg17 (accessed May 2017).
9 European Wound Management Association. 2013. EWMA Document: Debridement.An updated overview and clarification of the principle role of debridement. London: MEP Ltd.
10 European Wound Management Association. Position Document: Identifying criteria for wound infection. London: MEP Ltd, 2005.
11 Wounds UK. Quick guide to exudate management. 2013. Available from wounds-uk.com/pdf/content_10p44.pdf.
12 Zonghuan L, Aixi Y. Complications of negative pressure wound therapy: A mini review. Wound Repair and Regeneration 2014;22:457-61.