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Current perspectives in venous leg ulcer care

Jennifer Gatt
DipHE BA(Hons) PgDip
Tissue Viability Specialist Nurse
Scarborough, Whitby and Ryedale Locality of North Yorkshire York Community Mental Health Trust
Research Nurse
North Yorkshire and York Community and Mental Health Trust

In the current financial climate cost-effective wound care is a hot topic. Nurses should be aware of current evidence-based practice in venous leg ulcer management and some of the future developments

Tissue viability is a growing phenomenon, with leg ulcers affecting around 70,000-190,000 people in the UK at any one time in a year.1 The cost of this condition alone is estimated to be at least £168-198m per year.

Causes of venous ulceration
The main cause of venous leg ulcers is chronic venous hypertension due to incompetent valves within the perforator and deep veins.2 However, it is essential to bear in mind that several mechanisms work in combination to achieve venous return. Principally, these are changes in intra-abdominal and intra-thoracic pressures, and calf muscle and foot muscle contraction and movement.3
 
Valve failure causes further damage to other valves within the veins and allows the blood to flow back down the vessels, which leads to the development of varicose veins. Valve damage in deep and perforator veins leads to venous hypertension, concurrent oedema and the cessation of normal venous blood flow within the lower limb.
 
There are several theories to explain the cause of venous ulceration but these are mainly associated with venous hypertension; notably, the fibrin cuff theory, white cell trapping theory and mechanical theory.4-6 The 'trap' growth factor theory is associated with the fibrin cuff theory, which argues that growth factors required for normal tissue repair are trapped within the fibrin cuff, preventing their use.7 However, the exact mechanisms are still not known. Irrespective of the theoretical reasons for the occurrence of venous leg ulcers, the principles of management remain the same.

Assessment and diagnosis
Completing a thorough and holistic assessment allows the practitioner to make a diagnosis of the aetiology of the ulceration, determine the underlying cause and factors that influence and affect healing, and reduce the risks of avoidable delays in healing.3

Once a diagnosis has been reached, the assessment informs care planning and provides an insight into the potential acceptance (or rejection) of proposed treatments. It is essential to remember that diagnosis of the aetiology is paramount as this will affect the treatment decision.

The main aims of venous leg ulcer management
are to:

  • Reduce high blood pressure within the superficial venous system.
  • Assist venous return by increasing the speed of the venous blood flow in the deep veins.
  • Reduce the pressure differences between the capillaries and the tissues, which, in turn, will reduce the oedema.3
  • Addressing these principles will go some way to creating an ideal wound healing environment and reduce the risk of complications.

Therapy
In practice, nurses are faced with several dilemmas, including getting patients to accept compression therapy, choosing the correct system and attaining concordance with the treatment. Various sources of guidance are available that practitioners can use to influence and inform their decision-making with regard to the most appropriate care, for example, from the World Union of Wound Healing Societies, Royal College of Nursing and the Scottish Intercollegiate Guidelines Network.2,8-10

Multi-layer bandage systems
Compression therapy in the form of multi-layer graduated compression bandage systems remains the 'gold standard' treatment for venous leg ulcers.11 In a review of 39 randomised, controlled trials (RCTs) carried out in relation to compression therapy, it was concluded that ulcers heal faster with compression than they do without.11 It is essential to remember that both patient and practitioner factors can impinge on the effectiveness of compression therapy.2 The patient may have limited foot and calf muscle function, a grossly misshapen limb or poor tolerability to the form of compression applied. The skills of the nurse applying the compression therapy are also important, as are the available resources.

The mode by which the multi-layer systems work is based on Laplace's law, which states that the pressure exerted is proportional to the number of layers of bandage, multiplied by the bandage tension, which is then divided by the sum of limb circumference, multiplied by the bandage width, thus highlighting the importance of ascertaining ankle circumference and ensuring the correct application of these systems.3,12  It is vital to consider the choice of dressing to be used under the bandage systems. It is advocated that a simple low or non-adherent dressing is adequate as this allows the full potential of the compression system to be asserted on the limb and ensures the most effective level of compression is achieved.12

The use of these simple primary dressings only under compression bandage systems may pose a challenge to some practitioners and patients as their thoughts will be biased towards applying more absorbent dressings when exudate levels are such that there is strike through to the outer bandages. Anecdotally, advising the patient with highly exuding venous leg ulcers to apply absorbent wound pads externally, until a practitioner was available to renew the bandage system, resulted in notable changes in normally static ulcers. However, this phenomenon does need further and more stringent investigation.

For many years, the only treatment available was the four-layer elastic system based on the method devised by Charing Cross Hospital. However, compression therapy now comes in a plethora of forms, including:

  • Multi-layer elastic systems.
  • Two-layer inelastic systems.
  • Two-layer elastic systems.
  • Two-layer systems with a foam comfort layer.
  • Two-layer compression hosiery systems.

These choices give nurses more scope within their decision-making. However, the question remains regarding the effectiveness of each of these systems and the level of evidence to support the use of anything other than the 'gold standard' treatment.

A review by O'Meara et al found that multi-layer systems were preferable to single components and the elastic multi-layer systems appeared more effective than the multi-layer inelastic systems.11 It was also found that two-layer stocking systems were more effective than two-layer inelastic system (short stretch). Many patients fail to concord with multi-layer systems as they are unable to use their own footwear, don't like the
bulkiness of bandages and often find them too uncomfortable.13

Currently, there is limited evidence to support the use of two-layer hosiery systems as it has only been compared to two layer inelastic systems (short stretch) and not two-layer elastic systems.8 Moreover, at present there is no high-quality evidence to support the use of two-layer hosiery systems instead of four-layer elastic bandage systems.

This deficit is currently being addressed. York University Trials Unit is leading a national pragmatic RCT (VenUs IV) comparing four-layer elastic bandage systems with two-layer compression hosiery systems. The trial has several active sites in primary and acute care settings across England. Recruitment of participants is ongoing until 31 October 2011 and follow-up is until June 2012.

Patient self-care
The use of alternatives to four-layer elastic bandage systems may hold some advantages in the current financial climate. There appears to be a move away from practitioner application to encouraging patient self-care. The potential for self-care with some of the alternative treatments may increase concordance as it empowers patients to manage their condition. It has been suggested that self-care may be the way forward for chronic leg ulcer management.14

Where there is high-quality evidence available to support the use of specific compression interventions it is primarily based on healing rates, time to healing and recurrence of ulceration. Although these are valid and acceptable research outcomes, this may not be the most appropriate approach when faced with those venous leg ulcers that do not, and may never, heal.14 When encouraged to consider their leg ulcer as a chronic condition, patients tended to divert the focus of the treatment away from healing as the main expectation of care and focus on symptom management instead.13

Self-care and refocusing the expectations of patient and practitioner are only achievable when adaptations to treatment are made with this perspective in mind. Arguably, however, adaptations to care may be difficult to achieve if practitioners are still expected to consider only interventions that are supported by the highest level of research.

References
1.    Posnett J, Franks P. Skin Breakdown; The Silent Epidemic. London: Smith & Nephew; 2007.
2.    European Wound Management Association (EWMA). Position Document: Understanding Compression Therapy. London: MEP Ltd; 2003.
3.    Morrison M, Moffat C, Bridel-Nixon J, Bale S. Nursing Management of Chronic Wounds, 2nd Edition. London: Mosby; 1999.
4.    Burnand KG, Whimster I, Naidoo A, Browse NL. Pericappillary fibrin in the ulcer-bearing skin of a leg: the cause of lipordermatosclerosis and venous ulceration. BMJ 1982;285:107-2.
5.    Coleridge-Smith P, Sarin S, Hasty J, Scurr JH. Sequential gradient pneumatic compression enhances venous ulcer healing: a randomised controlled trial. Surgery 1988;108:871-5.
6.    Chant ADB. Tissue pressure, posture and venous ulceration. Lancet 1990;336:1050-1.
7.    Higley HR, Ksander GA, Gerhardt CO, Falanga V. Extravasation of macromolecules and possible trapping of transferring growth factor in ulceration. Br J Dermatol 1995;132:79-85.
8.    World Union of Wound Healing Societies (WUWHS). Principles of best practice: compression in venous leg ulcers. A consensus document. London: MEP Ltd, 2008.
9.    Royal College of Nursing (RCN). Clinical guidelines for the management of venous leg ulcers. London: RCN; 2006.
10.     Scottish Intercollegiate Guidelines Network (SIGN). Management of chronic venous leg ulcers: a national clinical guideline. Edinburgh: SIGN; 2010.
11.     O'Meara S, Cullum NA, Nelson EA. Compression for venous leg ulcers. Cochrane Database Syst Rev.2009;21(1):CD000265.
12.     Hopkins A. How to apply effective multilayer compression bandaging. Wound Essentials 2006;1:23-42.
13.    Briggs M, Flemming K. Living with leg ulceration: a synthesis of qualitative research. J Adv Nurs 2007;59(4):319-28.
14.     Brown A. Managing chronic venous leg ulcers: time for a new approach? J Wound Care 2010;19(2):70-4.
15.    Department of Health. National Service Framework for Long-term Conditions. London: DH, 2005.

Resource
York University Trials Unit
W: https://hsciweb.york.ac.uk:443/research/public/Group.aspx?ID=13#Projects

Your comments (terms and conditions apply):

"As mentioned that venous hypertension and incompetent valves are the main cause of venous leg ulceration, why is it patients can not seem to obtain surgery for varicose veins?" - Karen Henchliffe