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 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 ED 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 to vascular specialist for outpatient appointment
• e-Referral Service selection:
  • Specialty: Surgery - Vascular
  • Clinic Type: Not otherwise specified
  • Service: DRSS-Western-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