Nurses have an important role in managing intermittent claudication: nurses working in primary care, aged-care and the community have an important role to play in identifying and managing intermittent claudication--exercise-induced leg pain. Correct diagnosis and treatment can markedly improve a person" quality of life.

What is intermittent claudication? Claudication is derived from the Latin word "claudicatio", meaning to limp (1,2) and refers to exercise-induced leg pain. Clinical manifestations of arterial disease range from intermittent claudication at the lower end of the continuum, to limb threatening critical ischemia. (3,4,5,6)

Narrowed arteries

Intermittent claudication occurs when the arteries to, or in the leg, have been narrowed by 60 percent or more by atherosclerosis. (7) The arteries to, and in the leg, deliver blood to the muscle and tissue, supplying these with oxygen and nutrients to function. However, when we move or exercise, the muscles require more oxygen and nutrients from the blood to continue to function. When the arterial supply is unable to supply this, due to narrowing of the arteries, the muscle, having used its supply of oxygen and nutrients, builds up lactic acid. It is this build up that causes the pain in the Leg muscle--it's Like getting the stitch but it happens in the leg muscles. This is why when the person stops the exercise, the pain gradually eases, as the extra demand has stopped and the supply gradually catches up with the lesser demand of the muscles at rest.

The incidence of peripheral arterial disease (PAD) is around three percent for ages 40 to 59 years, dramatically increasing to nearly 20 percent for those more than 70 years old, and as high a 60 percent in those aged more than 85. (5,8)

It is projected that by 2020, with extended life spans and the aging "baby boomer" generation, there will be a 40 percent increase in the number of North Americans suffering from PAD. (8) No data was available for the incidence of PAD in New Zealand. However, the prevalence is thought to be similar to other Western countries. (9)

While this number appears high, approximately half this group are asymptomatic, misdiagnosed or undiagnosed. In the asymptomatic group, other medical conditions make it difficult for the person to walk fast enough or far enough to get the Leg pains. (3) In the misdiagnosed group, the leg pains are often put down to the aging or other medical conditions. In the undiagnosed group, it is often because they do not tell their health professional, or they have already developed sufficient collateral arterial circulation to counteract the narrowing of their leg arteries. (3)

'Cramping, tightness, aching'

People experiencing intermittent claudication describe the symptoms in their legs in a number of ways. They use terms such as pain, cramping, weakness, tightness, aching, tiredness or "giving out". It commonly occurs in the calf muscles, but also can affect the thighs and buttocks. Onset of pain can vary according to the amount of "work" the leg muscle is asked to do. If the person walks fast, climbs hills, walks over rough ground, sand or shingle, the onset of muscle pain is earlier than walking slowly. (4) While intermittent claudication is a not a life-threatening condition, it can have a major psychosocial impact. People with impaired walking ability due to intermittent claudication are at greater risk of frustration and embarrassment, as they are unable to walk without stopping, frequently due to the leg pain. They may also suffer toss of independence, unemployment, social isolation and depression. (10,11)

Diagnosis of intermittent claudication is through a simple non-invasive

peripheral vascular assessment. Most people are referred to a vascular surgeon for this assessment. Initial assessment usually takes the form of a medical history, specifically focusing on risk factors such as smoking, hypertension, hyperlipidema, diabetes and previous cardiovascular disease.

The impact on quality of life is investigated, in conjunction with a tower limb physical examination, which includes assessment of peripheral pulses and ankle brachial pressure indices (ABPIs). Ankle brachial pressure indices are a non-invasive objective measurement of the arterial perfusion of the tower extremities. They are essentially a comparison of blood perfusion between the arm and leg and are used as a screening and monitoring toot for patients who present with a "vascular" problem.

To complete the assessment, a shuttle test to record onset of "pain" (claudication distance) and when the person needs to stop (total walking distance) is performed. Diagnosis is based on this information.

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Treatment is aimed at relieving or improving the person's symptoms. In the past, first-line treatments were surgery, angioplasty or pharmacotherapy. Contemporary evidence-based treatment is risk factor management, to stow the progression of atherosclerosis, and walking exercise programmes to assist the development of collateral circulation. (5,12,13,)

However, before treatment, symptoms need to be detected and correctly diagnosed. As the Literature indicates, many patients go undiagnosised or are incorrectly diagnosed. This is where the nurse can play a crucial role. Nurses in general practice, aged care and community-based care, eg district nurses, are the ones to whom patients often mention their walking problems. Two simple questions--does the pain/discomfort only come on with exercise, eg walking? does the pain/discomfort ease when exercise stops?--can help determine if a person is experiencing intermittent claudication. If the answer to both these questions is "yes", then the symptoms the person is experiencing may be due to intermittent claudication. Nurses can then facilitate appropriate referral and treatment for the person. Appropriate referral, assessment and treatment for these people can ultimately lead to relief of symptoms and improvement in their quality of life.

TEST TO DETERMINE INTERMITTENT CLAUDICATION

Joe * is a 68-year-old male, married, with three adult children. He is an active, retired school teacher, with normal body mass indices and no history of any major illnesses. His medical history includes hypertension and hyperlipidema, both controlled with medication.

He is an ex-smoker, having stopped some ten years ago. Joe and his wife like to go for a daily walk. However, over the last three months, Joe has been finding this increasingly difficult, having to stop frequently during an hour-long walk. He has complained to his wife of pain in his left calf that goes away after resting for several minutes but returns within five minutes of recommencing their walk. His wife has dismissed it as Joe "getting older and slowing down."

Leg pains

He presents to the practice nurse for his three-monthly blood pressure check and, in general conversation, Joe tells the practice nurse about his leg pains. She questions him further, ascertaining that the pain is in his left calf, occurring only on exercise. She discusses her suspicions with Joe and asks him if he would consent to a simple non-invasive peripheral vascular test to ascertain if her suspicions are correct.

She gets Joe to rest for 20 minutes on the examination bed in her clinic room and at the end performs a lower Limb examination which includes palpation for peripheral pulses, capillary refill test, observation of tropic changes and pre/post exercise ankle brachial pressure indices (ABPIs). Joe then undergoes a walking test which records when the pain starts (claudication distance) and when Joe has to stop (total walking distance). This simple non-invasive test, using an anaroid blood pressure cuff and a hand-held Doppler, can indicate the presence of peripheral vascular disease. At the end of this, the practice nurse tells Joe he has intermittent claudication. She then explains how he can manage this effectively through a walking exercise programme. She arranges to review Joe again in three months when his next blood pressure assessment is due. At the next check, Joe reports a marked improvement--he is only having to stop once during an hour's walk. Joe's practice nurse reassesses his pre- and post-exercise APBIs, confirming no deterioration in these and a marked increase in his claudication distance and total walking distance. She completes her education regarding the need to continue the conservative management programme of exercise and risk factor management.

* Joe is a fictitous patient.

References

(1) Cantwell-Gab, K. (1996) Identifying chronic peripheral arterial disease. American Journal of Nursing; 96: 7, 40-46.

(2) Lewis, C.D. (2001) Peripheral arterial disease of the Lower extremity. The Journal of Cardiovascular Nursing; 15: 4, 45-63.

(3) Aronow, W.S. (2004) Management of peripheral arterial disease of the Lower extremities in elderly patients. Journal of Gerontology; 59A: 2, 172-177.

(4) Chant, T. (2004) Peripheral vascular disease. Primary Health Care; 14: 8, 29-34.

(5) Federman, D.G., Bravata, D.M. & Kirsner, R.S. (2004) Peripheral arterial disease: a systemic disease extending beyond the affected etremity. Geriatrics; 59: 4, 26, 29-30, 32, 34, 36.

(6) Olson, K.W.P. & Treat-Jacobson, D. (2004) Symptoms of peripheral arterial disease: A critical review. Journal of Vascular Nursing; 22: 3, 72-77.

(7) Bryant, J.L. & Turkoski, B.B. (1999) Relieving intermittent claudication: a nursing approach. Journal of Vascular Nursing; 17: 4, 81-85.

(8) The Society for Vascular Nursing. (2003) Vascular nursing scope of practice. Journal of Vascular Nursing; 31: 3, 106-109.

(9) Su, H., Gordon, M.K., Roake, J. & Lewis, D. (2006) Management of risk factors: a survey of New Zealand vascular surgeons. The New Zealand Medical Journal; 119: 1231._http://www.nzma.org.nz/journal/ 119-1231/1905/content.pdf. Retrieved 13/02/07.

(10) Binnie, A., Perkins, J. & Hands, L. (1999) Exercise and nursing therapy for patients with intermittent claudication. Journal of Clinical Nursing; 82: 190-200.

(11) Fletcher, L. (2006) Management of patients with intermittent claudication. Nursing Standard; 20: 31, 59-66.

(12) Hiatt, W.R. (2001) Medical treatment of peripheral arterial disease and claudication. New England Journal of Medicine; 344: 21, 1608-21.

(13) Treat-Jacobson, D. & Walsh, M.E. (2003) Treating patients with peripheral arterial disease and cLaudication. Journal of Vascular Nursing; 21: 1, 5-16.

This article was reviewed by Kai Tiaki Nursing New Zealand's practice article review committee in March 2008.

Dawn Sutton, RN, ADN, BN, MHlthSci (Nursing), is a vascular nurse in the Department of Vascular, Endovascular and Transplant Surgery, Christchurch Hospital, Canterbury District Health Board.