Chronic wounds are defined as wounds that fail to proceed through the normal phases of wound healing in an orderly and timely manner. A wound is generally considered chronic if it has failed to heal within 4-6 weeks. Chronic leg ulcers are defined as open lesions between the knee and the ankle that have not healed within 4-6 weeks. Most (around 70%) of leg ulcers occur because of venous insufficiency, arterial ulcers account for about 25% of leg ulcers and around 5% of leg ulcers have both venous and arterial components and are referred to as ulcers of mixed aetiology.
1. What is chronic venous leg ulcer?
A chronic venous leg ulcer is ‘an open lesion between the knee and the ankle joint that remains unhealed for at least four weeks and occurs in the presence of venous disease.
Guest and colleagues review of wounds in primary care found that community nurses care for 1.45 million people with wounds each year. Around 47% of wounds are acute wounds and 53% are chronic wounds. Leg ulcers account for 28% of the community nurses wound care caseload however just over half of all leg ulcers do not have a specified diagnosis.
In order to enable wounds to heal the nurse must determine the aetiology of the wound, address contributing factors whenever possible, care for the skin on the lower leg, protect the peri-wound area and treat the wound to enable healing to take place.
2. Diagnosis chronic venous leg ulcer
Many leg ulcers fail to heal because of inadequate assessment and treatment choices.
A comprehensive and holistic assessment is essential. This should comprise of history taking, physical examination of both legs and the feet and identification of any other clinical issues that may require intervention such as suspected or confirmed cardiac disease, diabetes mellitus and infections such as cellulitis. The assessment should take into account the person’s mobility levels, the impact the ulcer is having on the person’s life and the person’s aspirations in relation to treatment. Wound assessment should determine what type of wound the person has, its size, the condition of the wound bed, characteristics of any exudate and the level of pain the person is experiencing.
3. Treatment of venous and mixed ulcers
Treatment aims to treat any skin problems, protect the peri-wound area, use appropriate dressings to facilitate healing and address contributing factors such as venous disease and cigarette smoking.
Skin care
Ulcerated legs can be malodorous and uncomfortable and this can affect a person’s quality of life and discourage the person from meeting friends and family.8 Washing and caring for the person’s skin can improve morale and facilitate wound healing. Ulcerated legs should be washed with tap water and dried.
Venous leg ulceration is part of a continuum of venous disease that includes causes skin changes such as dryness and thickened areas of skin. Hyperkeratotic skin (thickening of the stratum corneum the outermost layer of the epidermis), should be removed to promote comfort and skin health.
Dead tissue on the skin can be removed using an active debridement pad Debrisoft, from Activa Healthcare uses a fleece-like contact layer to mechanically remove debris, necrotic tissue, slough and exudate.
The UCS debridement cloth—a pre-moistened single-use cloth—from Medi UK can also be used to debride wounds and remove scale from the skin. It has a mild cleansing agent that moistens and softens, making debridement more effective. A single treatment can provide significant debridement and does not cause pain or discomfort. It can be especially useful in removing dry dead tissue on legs.
Emollient therapy can be applied to promote skin health. This is more effective when dry dead skin is removed as emollients can penetrate the skin and hydrate it more effectively. It is important to provide an emollient preparation that the patient finds effective and acceptable.Creams containing urea can also be helpful as urea is an excellent moisturiser.
Protecting the peri-wound area
The skin around a leg ulcer can become macerated and damaged especially if the wound is exuding heavily.
A barrier film such as Cavilon barrier film (3M) or LBF (Clinimed) protects the peri-wound skin and aids healing.
Treating the wound
Wound healing consists of three phases that overlap. These are:
- Inflammatory phase – this occurs following haemostasis and lasts 1-4 days
- Proliferation phase – lasting 5-21 days
- Maturation phase – lasting 21 days to up to 2 years.
These phases must take place in the correct sequence and intensity to enable normal wound healing to take place. The nurse should select dressings that enable wound healing to take place. Wounds heal best in a warm moist environment with low levels of oxygen tension. Low oxygen tension leads to high levels of oxygen at the capillaries and low levels of oxygen at the wound edges. This provides the ideal environment for wound healing because granulation and wound healing is stimulated.
If there are concerns regarding blood supply to a wound, nurses should remember: ‘If there’s no blood supply keep it dry’ and seek expert advice.
Chronic wounds become stuck at a particular phase of healing. This is usually the inflammatory phase and the principles of dressing selection are to determine the description of the wound bed, to remove any dead tissue and help the wound to move on to the next phase of healing. Assessment of the wound bed enables the nurse to determine if the wound is necrotic, sloughy, granulating, epithelising or displaying signs of infection
Although debridement is not considered routine care, expert opinion and best practice documents emphasise the importance of using dressings to remove dead tissue to enable wounds to heal. A number of methods may be used to debride a wound. These include surgical debridement (using a sterile scalpel to remove dead tissue), medical debridement (using dressings, such as those containing honey or hydrogels) or the use of larval therapy.
In the absence of robust evidence, the selection of wound care products remains an art rather than a science and clinicians should be alert to an individual’s response to a particular treatment.
Using a simple system to classify the wound enables nurses to choose appropriate dressings.
Necrotic tissue or eschar is dead, devitalised tissue. It may be black or brown in colour. Necrotic tissue is initially brown and soft but becomes hard and black as it dehydrates. It can delay healing and provide a focus for infection. Necrotic tissue can be removed using surgical sharp debridement. This should only be carried out by appropriately trained and competent nurses.