Acute limb ischaemia

Question 1

A 70-year-old man presents to the Emergency Department with an acutely painful and pulseless right leg.

AND

A 70-year-old man with known atrial fibrillation presents with acute pain and weakness of the right hand. The brachial and radial pulses are impalpable. How would you assess and manage him?

Impression/DDx/Goals

Answer 1

Impression:
This is likely a presentation of acute limb ischaemia. Concerned about long-term complications of prolonged ischaemia, so this would constitute a surgical emergency requiring rapid treatment and management.

Aetiology

• thrombosis
• embolism

DDx

• musculoskeletal injury (fracture, etc)
• compartment syndrome
• vascular: acute on chronic limb iscaemia, dissection, popliteal aneurysm, thromboembolism

Goals of management

• Identify cause of presentation and treat emergently
• arrange prompt transfer to vascular theatres for definitive treatment
• reduce long-term risk factors for further ischaemic events

Question 2

Acute limb ischaemia - History

Answer 2

History:

• Sx: (6 P’s) pain, pallor, pulselessness, parasthaesia, paralysis, poikilothermia
• Risks: hypercoagulable state as per Virchow’s triad

Question 3

Acute limb ischaemia - Examination

Answer 3

Examination

• General obs + vital signs
• Assessment of pulses
• Neurological examination
• Rutherford grading of severity - likely 2B based on stem

Question 4

Acute limb ischaemia - Investigations

Answer 4

Investigations
- clinical diagnosis, however would want to determine source

• Bedside: ECG, ECHO, vitals, VBG
• Bloods: trops, coags (serial), FBC, UEC (renal failure), LFT
• Imaging: ABI, doppler ultrasound, CT angiography, DSA (in theatres)

Question 5

Acute limb ischaemia - Management

Answer 5

Management
This is a surgical emergency, prioritise emergent vascular surgery for clot retrieval.

Supportive

• IV heparin 80 units then 18 units/kg/hour, adjusted according to APTT, or subcut UFH as is short acting and can thus ceases activity shortly after stopping administration.
• consider fibrinolysis with specialist guidance, or if theatres unavailable in timely manner
• do not elevate the limb

Definitive

• angiography and vascular surgery for clot retrieval/embolectomy
• ballooning/stenting
• bypass surgery
• BKA/amputation depending on severity

Long-term

• lifestyle modifications for cardiovascular risk factors
• consider starting/optimising SABA
• long-term rehab options with allied health involvement