Signs and Symptoms

• Pain of sudden onset at rest or walking short distances (calf, thigh or entire limb)
• Always affects the foot (calf pain with no symptoms in the foot is not typical of ischaemia)
• Interferes with sleep/ worse with elevation of the limb / better with limb dependent

History and Examination

History:

Relating to embolus:

• Sudden onset of severe limb pain, numbness and paralysis
• Underlying cause (eg. AF without anticoagulation; limb trauma)

Relating to thrombosis ("thrombosis-in-situ" or "acute on chronic ischaemia")

• Known arteriopath / vascular risk factors
• Pre-existing symptoms of peripheral arterial disease (intermittent claudication)
• Sudden deterioration in claudication distance / rest pain
• Known lower limb aneurysm (femoral or popliteal)

Examination:

Absolute ischaemia

• The "six P's": Pale (bloodless limb), Painful, Pulseless, Perishing cold, Paraesthaesia, Paralysis
• Absent pulses on affected side with normal pulses on the other side suggest embolism
• Atrial fibrillation – commonest cause of embolism
• Loss of sensation, paralysis and muscle tenderness are signs of advanced ischaemia and need for emergency intervention

Relative ischaemia

• Symptoms without the features of absolute ischaemia
• Abnormal pulses in both legs
• Doppler examination – absent or abnormal flow signals at ankle/foot

Differential Diagnoses

• Many other causes of leg pain – the symptoms bulleted above are the key to diagnosis.
• DVT causes leg swelling and sometimes blue discoloration, but hand-held Doppler examination shows good arterial flow signals at the foot/ankle.

• Bloodless limb
• Rest pain and altered sensation

Absolute ischaemia: None – Emergency referral

Acute onset of relative ischaemia: None – Emergency referral

• Absolute ischaemia:
  • Emergency referral to the vascular service
  • Analgesia

• Relative ischaemia
  • Risk factors modification:
    • Smoking advice
    • Diabetic review
    • Statin therapy
    • Blood pressure control
    • Antiplatelet therapy
  • Urgent outpatient referral to the vascular service

Referral Criteria

• Absolute or relative ischaemia of acute onset

Referral Instructions

• Absolute ischaemia – immediate via Emergency Department or on call general surgical registrar
• For discussion with a consultant ring switchboard and ask for vascular surgeon of the week

Relative ischaemia –urgent referral for outpatient appointment

• Referral to vascular specialist
• e-Referral service selection:
  • Specialty: Surgery - Vascular
  • Clinic Type: Not otherwise specified
  • Service: DRSS-Northern-Surgery Vascular- Devon ICB- 15N

Referral Form

DRSS Referral Form

Pathway Group

This guideline has been signed off on behalf of NHS Devon.

Publication date: May 2024