Peripheral Arterial Disease

 

Peripheral arterial disease is caused by atherosclerosis, a narrowing or occlusion of the peripheral arteries, affecting the blood supply to the lower limbs.  Acute limb ischaemia is a quickly developing or sudden decrease in limb perfusion, usually producing new or worsening symptoms and signs, and often threatening limb viability. Acute limb ischaemia is most commonly caused by thrombosis at the site of an atherosclerotic stenosis.  It can occur in people who have had no previous symptoms.  Chronic limb ischaemia can present as intermittent claudication, when diminished circulation leads to pain in the lower limb on walking or exercise, or critical limb ischaemia, when circulation is so severely impaired that there is an imminent risk of limb loss.  Critical limb ischaemia is usually caused by obstructive atherosclerotic arterial disease

When to suspect peripheral arterial disease

Suspect acute limb ischaemia when:

  • There is an onset of leg pain over minutes, hours, or days associated with a loss of pulses and pallor
  • There may be features such as coldness and cyanosis of the limb, or loss of muscular power and sensation (these may be subtle or absent)

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Suspect chronic limb ischaemia when:

  • There is progressive development of a cramp-like pain in the calf on walking, or unexplained foot pain at rest (worse at night)
  • There are non-healing wounds on the lower limb
  • Peripheral pulses are absent or difficult to feel

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Diagnosis

Acute limb ischaemia

Typical features of acute limb ischaemia include:

  • Pain — constantly present and persistent
  • Pulseless — ankle pulses are always absent
  • Pallor (or cyanosis or mottling)
  • Power loss or paralysis
  • Paraesthesia or reduced sensation or numbness
  • Perishing with cold

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If there is ischaemia due to an embolus:

  • Onset is acute (seconds or minutes)
  • Ischaemia is usually profound (because there is no collateral circulation)
  • Skin changes of the feet (such as marbling) may be visible. This can be a fine reticular blanching or mottling in the early stages, progressing to coarse, fixed mottling
  • There is not usually a history of claudication, and pulses are usually present in the other leg

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If there is ischaemia due to thrombosis:

  • Onset is insidious (hours or days)
  • Ischaemia is less severe (due to collateral circulation)
  • There will often be a history of claudication, and pulses in the other leg may also be absent

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Chronic limb ischaemia

NOTEChronic limb ischaemia may cause intermittent claudication or critical limb ischaemia

Both intermittent claudication and critical limb ischaemia cause:

  • Calf pain when there is narrowing of the femoral or popliteal artery. Less commonly calf, hip, buttock, and thigh pain occurs when there is narrowing of the iliac arteries

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Features of intermittent claudication include:

  • Cramp-like pain after walking a predictable distance that is relieved by rest and reproduced by walking the same distance again
  • Distal pulses that may be felt at rest but disappear on exercise to the point of pain

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Features of critical limb ischaemia include:

  • Rest pain, which may be described as relentless, unbearable, or burning. This may be worse at night because the elevation of the leg in bed further limits perfusion. People may report sleeping with the leg hanging out of bed, or sleep in a chair. Rest pain is usually preceded by a history of intermittent claudication but occasionally is not (for example intermittent claudication may not have been clinically apparent in a person with limited mobility)
  • Dependent rubor (red or purple colour of the leg when not elevated), early pallor on elevation of the extremity, and reduced capillary refill
  • Skin changes (not always a feature), including impaired wound healing, ischaemic ulcers, and gangrene
  • Absent foot pulses

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Measure the ankle brachial pressure index (ABPI) to confirm the diagnosis of peripheral arterial disease. This should be undertaken by an experienced operator using validated equipment

  • An ABPI ratio of less than 0.9 indicates the presence of peripheral arterial disease, with some classifications using a threshold value of less than 0.5 for critical limb ischaemia
  • However, a resting ABPI of more than 0.9 does not mean that peripheral arterial disease is not present. Values of more than 1.3 may indicate arterial stiffening which can be associated with peripheral arterial disease (for example in people with diabetes)
    • If the ABPI is high (1.3 or more), consider the possibility of peripheral arterial disease, particularly if the person has diabetes or renal failure. Take into account other symptoms and signs, and seek specialist advice if unsure of the diagnosis
  • If an experienced operator using validated equipment is not able to detect an ankle pulse on Doppler, consider the possibility of acute limb ischaemia. If there are also clinical features of acute limb ischaemia, seek immediate specialist advice

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Management

Acute limb ischaemia

If acute limb ischaemia is suspected, arrange emergency assessment in a vascular surgery unit

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  1. Ensure that the person has been offered appropriate follow up by the vascular department depending on the cause of their acute limb ischaemia.
  2. For people with peripheral arterial disease, offer information, advice, support, and treatment regarding the secondary prevention of cardiovascular disease.
    1. For more information on the management of cardiovascular risk, click here - you will also find useful information at this link on the following:
      1. Smoking cessation
      2. Diet, weight management, and exercise advice
      3. Alcohol consumption
      4. Lipid modification therapy
      5. Plant stanols and sterols
    2. For information on the prevention, diagnosis, and management of diabetes, click here
    3. For information on the prevention, diagnosis, and management of high blood pressure, click here

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Critical limb ischaemia

  1. Urgently refer to a vascular multidisciplinary team (unless clinical judgement deems this inappropriate, for example in a palliative care situation).
  2. Manage pain:
    1. Offer paracetamol and either weak or strong opioids, depending on the severity of pain
      1. Also offer drugs such as laxatives and anti-emetics to manage the adverse effects of strong opioids in line with the person's needs and preferences
      2. Strong opioids are recommended for short-term use only
    2. Refer to a specialist pain management service if:
      1. Ongoing high doses of opioids are needed for pain control or there are concerns about rapid dose escalation and unacceptable pain relief
      2. The person prefers not to be referred to a vascular multidisciplinary team, or revascularization is inappropriate or impossible (for example in a palliative care situation)
      3. The person has undergone revascularization or amputation and pain persists
  3. Offer advice on:
    1. Keeping ischaemic feet clean to avoid infection, and being careful to avoid injury when cutting the toenails
    2. Driving:
      1. If the person holds a bus, coach, or lorry licence, advise them that they should inform the Driver and Vehicle Licensing Agency (DVLA) about their peripheral arterial disease.  Relicensing may be permitted if there is no symptomatic myocardial ischaemia and exercise and functional requirements can be met
      2. Drivers with a car or motorcycle licence do not need to tell the DVLA

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Intermittent claudication

  1. If available, offer a supervised exercise programme to all people with intermittent claudication. This involves:
    1. Two hours of supervised exercise a week for a 3-month period
    2. Encouraging people to exercise to the point of maximal pain
  2. If supervised exercise is not available, consider suggesting unsupervised exercise (using clinical judgement and taking into account the person's motivation and comorbidities)
    1. This involves advice to exercise for approximately 30 minutes three to five times per week, walking until the onset of symptoms, then resting to recover
  3. Refer for consideration of angioplasty or bypass surgery when:
    1. Advice on the benefits of modifying risk factors has been reinforced, and
    2. A supervised exercise programme has not led to a satisfactory improvement in symptoms
  4. Consider prescribing naftidrofuryl oxalate if:
    1. Supervised exercise has not led to a satisfactory improvement, and
    2. The person prefers not to be referred for consideration of angioplasty or bypass surgery
  5. Review progress after 3–6 months and discontinue naftidrofuryl oxalate if there has been no symptomatic benefit
  6. Offer advice on driving:
    1. If the person holds a bus, coach, or lorry licence, advise them that they should inform the Driver and Vehicle Licensing Agency (DVLA) about their peripheral arterial disease. Relicensing may be permitted if there is no symptomatic myocardial ischaemia and exercise and functional requirements can be met
    2. Drivers with a car or motorcycle licence do not need to tell the DVLA

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Doppler studies

If a Doppler study to assess vascular flow is required, please refer to the East Kent Vascular Centre at East Kent Hospitals where it will be performed by a Vascular Nurse Specialist

Advice and Guidance is being made available for all specialties, and is being provided by consultant specialists at East Kent Hospitals.  To make a request or to check to if a query has been answered, you will need to log in via the electronic Referral System (eRS)

Click here for the "how to access" e-Referral Advice and Guidance Manual for instructions on how to make a request and check responses

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