Issue 19 June 2005
General points
- Leg ulcers affect 1–2% of the population in their lifetime, with the highest prevalence occurring in the elderly
- Two-thirds of ulcers are venous in origin
- Ankle Brachial Pressure Index (ABPI) reading is essential to rule out significant arterial disease
- Effective treatment and management strategies depend on correct assessment and diagnosis including a pain assessment using a recognised pain assessment tool
- Continuous assessment is essential to monitor progress and recognise any factors that are impeding healing.
Background
Leg ulcers affect 1- 2% of the population, with highest prevalence in the elderly. Up to 60% of patients experience two or more episodes.(1) It is estimated that 25-50% of community nursing time is spent treating leg ulcers.2 Current best practice on leg ulcer assessment is summarised in this Review.(2)
Aetiology
Accurate diagnosis of ulcer aetiology is important to avoid harm from inappropriate treatment.(2) Approximately two-thirds of ulcers are venous in origin. Arterial and mixed (arterial and venous) ulcers account for most of the remainder. A small number of ulcers are caused by other conditions such as neuropathy, skin malignancy, trauma, blood disorders, vasculitis and infectious diseases.
Common indicators for venous and arterial ulcers:
Venous
Previous deep vein thrombosis, varicose veins, immobility, obesity, minor level of trauma, recurrent ulcer, and lower leg fracture.
Arterial
Smoking, hyperlipidaemia, ischaemic heart disease, stroke, hypertension, diabetes, claudication and rest pain.
Other causes and co-morbidities
Other local causes of ulceration are skin malignancy, diabetes, dermatitis, and vasculitis such as that associated with rheumatoid arthritis. Signs of malignancy are irregular nodular appearance of the ulcer surface, raised or rolled edge, raised tissue above the ulcer base, rapid increase in size and failure to respond to treatment. Specialist assessment of these patients should be considered.
Clinical Assessment
Clinical assessment should take place if there is no improvement in a wound at 4-6 weeks. As ulcer aetiology is often multifactorial, the assessment should include the whole patient as well as the ulcer itself. Ongoing assessment is essential to monitor progress.
Ankle Brachial Pressure Index (ABPI)
Palpable pulses alone are insufficient to exclude arterial disease. There is good evidence to support screening all ulcers using Doppler ultrasound to determine an ABPI.(2) An ABPI of <0.8 indicates arterial disease, requiring further investigation in conjunction with a vascular specialist. In patients with diabetes, chronic renal failure or leg oedema, the ABPI reading may be falsely elevated. It is essential that Doppler ultrasound is undertaken by a trained practitioner.
Limb assessment
Signs of venous hypertension include oedema, pigmentation and lipodermatosclerosis especially around the lower calf and ankle. Varicose veins may be present.
Signs of arterial insufficiency include ischaemic skin changes such as hair loss and nail thickening. The detection of underlying joint problems and neuropathy is essential.
Ulcer assessment
The cause of the ulcer and history of previous ulceration should be recorded. The following specific features should be noted: position, size, base (sloughy, necrotic, or granulating), margin, surrounding tissue condition, and depth. The surface of the ulcer should be measured at regular intervals to monitor progress. Maximum length and width measurements, photographs or tracings onto transparencies are useful methods.
Venous ulcers are often shallow with a pink base, and can cover an extensive area.
Arterial ulcers tend to occur on the toes, foot and calf and are often deep, sloughy, and less extensive than venous ulcers. The foot may appear cold and mottled.
Pain assessment
Pain is classically associated with arterial ulcers, but a significant proportion of patients with venous ulcers also report moderate to severe pain.(1) A pain assessment using a recognised pain assessment tool should be completed as part of the ulcer history. Tools can be visual (e.g Faces scale) or numerical/verbal (e.g Numerical Rating Scale or Verbal Rating Scale).(3) The scale chosen will depend on patient needs but once chosen should be used consistently.
Factors Delaying Healing
These should be identified at the outset and revisited during reassessment.
Patient health history and lifestyle: poor nutrition, smoking, patient attitudes and beliefs, anaemia, some medications, immobility, superficial venous insufficiency, and an ABPI of <0.8.
Ulcer history: presence of 50% slough over the ulcer base, larger size, chronic wound requiring wound bed preparation, long duration and infection.
Diabetes
Diabetics may produce unreliably high and misleading ABPI readings secondary to leg artery "incompressibilty" associated with arterial wall calcification.(2) Arterial ulcers are more common, but the ulcer may have arterial, venous and neuropathic components. Infection may also be a problem.
Criteria for Early Specialist Referral
- Uncertain aetiology
- Atypical distribution
- Suspicion of malignancy
- ABPI <0.8
- Surgically correctable superficial venous insufficiency
- Diabetes
- Rheumatoid arthritis or other suspected condition associated with vasculitis
- Dermatitis refractory to topical steroids
- Failure to respond to conventional treatment
Issues for ACC
ACC provides cover and entitlements for personal injury. If a leg ulcer is the consequence of a pre-existing disease or other underlying condition, rather than the personal injury suffered, the person will not be entitled to cover from ACC. It is important to consider the nature and cause of any ongoing problems and establish a causal link between these and personal injury.
References
- Moffat C, Harper P. Access to Clinical Education: Leg ulcers. Edinburgh: Churchill Livingstone, 1997.
- New Zealand Guidelines Group. Care of People with Chronic Leg Ulcers, An evidence based guideline. 1999.http://www.nzgg.org.nz/guidelines/0008/ACF672.pdf
- World Union of Wound Healing Society. Principles of best practice: Minimising pain at wound dressing-related procedures. A consensus document. London: MEP Ltd, 2004. www.wuwhs.org