Acute Limb Ischaemia

Acute limb ischaemia refers to a sudden decrease in limb perfusion (onset <2 weeks) that threatens limb viability

Two main causes of acute limb ischaemia: ^[Ref]

• Thrombosis (from atherosclerotic plaque rupture in underlying PAD) – 80-85%
• Embolism (most common from AFAtrial fibrillation)

Acute limb ischaemia often presents as acute-on-chronic limb ischaemia. Where patients with a history of PADPeripheral arterial disease (e.g. intermittent claudication / resting leg pain + cardiovascular risk factors) suddenly progress into acute limb ischaemia (e.g. claudication → constant severe pain, or worsening resting pain)

6Ps of acute limb ischaemia: (the development of all 6 Ps in clinical practice is rare) ^[Ref]

• Pain – the earliest and most common symptom
• Pallor
• Perishingly cold
• Pulselessness
• Late findings (objective neurological deficit → indicate nerve ischaemia)
  • Paraesthesia
  • Paralysis – latest and poor prognosis (indicates irreversible ischemia)

Immediate management in ALL patients with suspected acute limb ischaemia:

• IV unfractionated heparin (most important initial management – to prevent thrombus propagation and distal emboliation)
• Oxygen and IV fluids
• Analgesics (IV opioids often 1st line) (NSAIDs should be avoided)

• Refer all patients to vascular surgery

Perform ALL the following to work out the Rutherford class

• Clinical examination
• Hand-held Doppler

Definitive management depends on the Rutherford class: