Acute limb ischaemia

Theory

Embolic – will lodge at branch point of artery (aortic bifurcation, common iliac, common femoral, adductor canal).

Thrombotic – a diseased peripheral vessel can thrombose causing acute ischaemia.

Immediate intern management

Suspect and make the diagnosis.
IV access, basic set bloods (FBE, U&E, INR, GandH).
Nil orally, gentle IV fluids.
Analgesia.
Keep the limb warm (blanket/cotton wool).
Nurse limb in dependent position.
Inform unit and surgical registrar.
Organise appropriate investigations:
- Arterial US
- CT angiogram
- ? Transfer.

Note: In very severe ischaemia, surgery may be required very urgently and investigations (if any) may take place in operating theatre.

Differential diagnosis

Common

Cellulitis
Septic arthritis
Acute gout
DVT

Uncommon

Allergic reaction
Compartment syndrome
Referred pain
Acute fracture

Practical tips

The diagnosis is difficult, but needs to be excluded in a suddenly painful limb
Clinical features can be absent or subtle
Duration of ischaemia is critical for limb salvage
Asymmetrical pulses are a very useful hard sign
Inform superiors early

Clinical features

History

Acutely painful limb
Risk factors: AF, PVD, atrial clot, ventricular aneurysm

Examination

Pale or mottled appearance
Swollen
Cold and tender to touch
Decreased capillary refill
Absent or asymmetrical peripheral pulses
Diminished sensation – indication for urgent surgery
Diminished muscle movement – indication for urgent surgery

Investigations (urgent) diagnostic:

Lower limb arterial ultrasound
- First line test

MRA/CT peripheral angiogram
- Second line investigation

Peripheral arterial angiography
- Gold standard for acute limb ischaemia

Investigations – underlying factors:

ECG ?AF
Cardiovascular risk factors
Echocardiogram

Ischaemic time

Time is the most critical determinant of outcome
Ideally should be less than six hours
After eight hours, survival of muscle is significantly at risk

Definitive management