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Intermittent claudication/ critical ischaemia (Guidelines)



Presentation and work up of patients with peripheral vascular disease

  • This guideline can be used for patients with claudication and critical ischaemia in the lower limb (the two forms of chronic ischaemia)
  • Patients with acute limb ischaemia (the six ‘P’) need to be admitted immediately
  • The guideline can also be used for patients with a ‘diabetic foot’


  • Presenting symptoms: claudication and/or rest pain and/or ulceration
  • Date of onset of symptoms and progression
  • Impact on lifestyle
  • Conventional risk factors
    • Smoking (never, ex, current – with pack years)
    • Diabetes
    • Hyperlipidaemia
    • Hypertension
  • Other predisposing factors:
    • Physical inactivity
    • Obesity
    • Thrombophilia
    • Family history of premature onset of arterial disease
  • Other manifestation of arterial disease
    • Cerebrovascular disease
    • Ischaemic heart disease
    • Aneurysm
  • Drug history
  • Response to treatment in primary care (if applicable)


  • Body mass index
  • Heart rate and rhythm
  • Blood pressure in both arms
  • Abdominal examination for aortic aneurysm
  • Palpation of pulses in all four limbs
    • Brachial
    • Radial
    • Femoral
    • Popliteal
    • Posterior tibial
    • Dorsalis pedis


  • The following blood tests are mandatory:
    • Full blood count
    • Electrolytes, urea, creatinine and GFR
    • Fasting glucose
    • Fasting lipid profile
  • Measurement of Ankle Brachial Pressure Index is optional (ABPI)
    • May supplement the findings on physical examination
    • Should not delay referral of patients with critical ischaemia
  • ECG in patients with abnormal rate or rhythm

Diagnosis of peripheral arterial disease

  • Diagnosis of peripheral arterial disease in the limb in question is likely if at least two of the following criteria are present:
    • Claudication or rest pain or ulceration
    • Absence of both posterior tibial and dorsalis pedis
    • ABPI less than 0.9
  • Consider alternative causes where in doubt:
    • Osteoarthritis
    • Nerve root compression
    • Spinal stenosis
    • Chronic venous insufficiency
  • Differentiate into claudication and critical limb ischaemia
    • Claudication: symptoms purely related to walking, no tissue loss
    • Critical ischaemia: rest pain and/or ulceration plus reduced ABPI (typically less than 0.5)
  • Patients with known diabetes and ulceration in a foot
    • Follow pathway for critical ischaemia
    • Note that rest pain may be absent due to neuropathy
    • As a rule a diabetic patient with a foot ulcer and no palpable pulse in the foot should be assumed to have critical ischaemia
    • Note that ABPI measurement is not reliable

Management of claudication

  • Reassure
    • Most patients improve with conservative treatment
    • The limb is not at risk unless disease is allowed to progress
  • Explain the main implication of claudication
    • Claudication is a marker for generalised atherosclerotic disease
    • The patient is at increased risk of suffering myocardial infarction or stroke
  • Risk factor modification where appropriate
    • Active smoking cessation management
    • Optimise diabetes control
    • Optimise blood pressure control
  • Secondary prevention
    • All patients with symptomatic peripheral arterial disease should take Aspirin or Clopidogrel (grade A recommendation, SIGN 89)
    • All patients with peripheral arterial disease should take a statin if tolerated (SIGN 89 recommends statin if total cholesterol greater than 3.5; further evidence suggests that statins improve claudication symptoms³)
  • Encourage exercise
    • Regular walking is the best exercise for lower limb claudication
    • Teach the patient to ‘walk through the pain’
  • Consider a vasodilator
    • Naftidrofuryl is the only drug recommended in SIGN 89 for NHS Scotland
    • Stop Naftidrofuryl if there is no improvement after a trial period
  • Discuss further treatment plan
    • The majority of patients can be managed in primary care
    • Specialist referral is usually not justified at the first presentation unless the diagnosis is in doubt

Management of critical limb ischaemia

  • Explain the implications of critical ischaemia
    • The limb is at risk
    • The patient has generalised atherosclerotic disease and is at a high risk suffering other arterial events
  • Urgent risk factor modification where appropriate
    • Active smoking cessation management
    • Review diabetes control
    • Review blood pressure control
  • Commence secondary prevention drugs immediately
    • Aspirin or Clopidogrel
    • Statin
  • Prescribe appropriate analgesic
  • Provide wound care
    • As a rule keep the wound dry
    • Consider bacteriostatic dressing (not systemic antibiotics unless there is ascending cellulitis)
    • Offload pressure
  • Refer without delay

Specialist referral for patients with claudication

  • Refer patient if claudication symptoms continue to interfere significantly with life style after a trial of conservative management
  • Discuss expectations
    • Further review of risk factor control and secondary prevention
    • Poor risk factor control is a relative contraindication to any invasive procedure
    • Patient may be offered to take part in a structured exercise programme
    • Patient may have an angiogram (usually CT or MR) with a view to identify lesions amenable to angioplasty or surgery
  • Address referral letter to Vascular clinic (not Nurse Specialist at present)
  • Grading of the letter by referrer is not necessary
    • The main factor for grading by the receiving Consultant is interference of symptoms with life style
    • As a rule patients with claudication will be seen within 6 weeks

Specialist referral of patients with critical limb ischaemia

  • All patients with critical limb ischaemia should be referred for specialist assessment without delay
  • Criteria for emergency admission
    • Patient requires opiates to control rest pain
    • Advanced tissue loss
    • Ascending cellulitis
  • Outpatient referral to Vascular Clinic (not Leg Ulcer clinic)
    • The letter should specify that the patient is suspected to have critical ischaemia
    • Grading by the referrer is not necessary
    • As a rule patients with critical ischaemia will be seen within one week
    • Patients with a ‘diabetic foot’ may be referred to the Diabetic Foot Clinic if the dominant issue is neuropathy (DFC)
  • Discuss expectations
    • The objective is symptom control and limb salvage where possible
    • The majority of patients with critical ischaemia will have an angiogram (usually CT or MR) with a view to plan reconstruction
    • Reconstruction may involve angioplasty, open surgery or a combination of both
    • In some cases an amputation is the only option, counselling in primary care may be appropriate
    • Further review of risk factor modification and secondary prevention

Diabetic foot clinic referral guidance

Referral guidance for multi-professional diabetes foot ulcer clinic

This clinic runs on the first Thursday of the month. Services involved are Diabetology, Vascular Services, Orthotics, and Podiatry.  Telephone referrals are accepted and should be followed up by communication e.g. letter, SCI-DC letter/comments section completed.

OPTIONAL WOUND CARE INVOLVES                                                                       REFERRAL CRITERIA
  •  Wound management                                                                        Non healing diabetes foot ulcer (>4/52)
  •  Pressure relief*                                                                      Presenting ulcer with previous history of ulceration
  •  Infection control                                                                    Presenting ulcer with previous vascular intervention
  •  Footwear*                                                                                   Presenting ulcer with previous amputation
  •  Education
This should be practised at all times


  •  Palpation of pulses "
  •  Doppler ultrasound where available ""
  •  Presence of infection- swab results
  •  Presence of neuropathy

" In diabetes the presence of large vessel pulses may not exclude large vessel disease due to the high prevalence of vascular calcification nor does it exclude small vessel disease

 "" A monophasic pulse would be indicative of vascular disease.

  •  Smoking
  •  Glycaemic control
  •  Weight management
  •  Social circumstances
  •  Rest includes appropriate offloading techniques over 24hrs
  •  Diabetes Centre, Raigmore Hospital Tel. No. 01463 255930

Any concerns about diabetes foot ulceration pre or post clinic day should be fielded through the CHP Specialists Podiatrists.

  •  Podiatry Diabetes Co-ordinator, Medical Centre, Martha Tce,. Wick, Tel. No. 01955 604758
  •  Diabetes Specialist Podiatrist, Diabetes Centre, Raigmore Hospital, Inverness, Tel. No. 01463 255937
  •  Diabetes Specialist Podiatrist- MHCHP Tel. No. 07786190839


Ankle brachial pressure index

 The ankle brachial pressure index is a relatively simple method for quantifying the severity of arterial occlusion in the leg.

Is it is important to note that ABPI’s can only supplement clinical history and examination. There are many reasons for false high or low readings.

ABBI readings are particularly unreliable in diabetic patients. The readings tend to be falsely elevated due to rigidity of the of the calf vessels.

ABPI measurement should not delay referral in critical ischaemia


  • A blood pressure cuff is inflated around the lower calf muscle above the ankle joint, and a doppler ultrasound probe placed over the dorsalis pedis artery.
  • The maximum cuff pressure at which the Doppler signal (arterial waveform) can just be heard is recorded.
  • This should be repeated with the probe placed over the posterior tibial artery.
  • The higher of the two readings is related to the pressure measured over the brachial artery.
  • ABPI = brachial occlusion pressure/ankle occlusion pressure
  • By definition peripheral arterial disease is present if the ABPI is less than 0.9. However, many patients with reduced ABPI are symptom free.
  • The following table shows typical ABPI readings in various clinical states:

Clinical status


Symptom free

Greater than or equal to 0.9

Intermittent claudication

0.89 to 0.5

Rest pain

0.49 to 0.3

Ulceration and gangrene

Less than or equal to 0.29

Patient information

Patient information can be accessed here


Abbreviation Meaning
GFR Glomerular filtration rate
ECG Electrocardiogram

Last reviewed: 20/10/2022

Next review date: 31/10/2023

Author(s): Consultant Vascular Surgeon.

Approved By: TAM subgroup of ADTC

Reviewer name(s): Consultant Vascular Surgeon.

Document Id: TAM423

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