Vascular: Acute Limb Ischaemia

Question 1

Outline the pathophysiology of acute limb ischaemia

Answer 1

Sudden decrease in limb perfusion that threatens the viability of the limb

Complete or partial arterial occlusion = rapid ischemia

Will lead to irreversible tissue damage within 6 hours

Question 2

Outline the aetiology of an acute limb ischaemia

Answer 2

Thrombosis in situ = atheroma plaque ruptures and thrombus forms

Embolism = may be result of AF, post MI mural thrombus, AAA, prosthetic heart valves

Trauma

Question 3

What are the symptoms of acute limb ischaemia

Answer 3

Pain
Pallor
Pulselessness
Paraesthesia
Perishingly cold
Paralysis

Question 4

What investigations should be performed for acute limb ischaemia?

Answer 4

Causes of potential embolisation should be explored

Bloods = lactate, group and save

ECG

Doppler US both limbs

CT angiography

Question 5

How is acute limb ischaemia managed?

Answer 5

A-E = high flow O2, IV access

Therapeutic dose heparin or preferably a bolus dose then heparin infusion

Embolectomy

Local intra-arterial thrombolysis

Bypass surgery (if there is insufficient flow back)

Angioplasty

Irreversible limb ischemia = urgent amputation

Long term = education (regular exercise, smoking cessation, weight loss), aspirin, clopidogrel, warfarin, DOAC, OT, PT

Question 6

What are the possible complications from acute limb ischaemia?

Answer 6

Mortality 20%

Ischaemic reperfusion syndrome = compartment syndrome, hyperkalaemia, acidosis, myoglobin causing AKI