Acute limb ischaemia (Complete)

Question 1

What is acute limb ischaemia?

Answer 1

Severe, symptomatic hypoperfusion of a limb occuring for <2 weeks

Question 2

Acute limb ischaemia is considered a surgical emergency. How quickly from onset of symptoms should correction be done?

Answer 2

Ideally within 4-6 hours

Question 3

What are the main features of acute limb ischaemia?

Answer 3

Always think of the 6 Ps:

Pulseless

Pain

Pale

Paralysis

Paraesthesia

Perishingly cold

N.B. Must always consider acute limb ischaemia if 1 or more of the 6 Ps are present in acute setting

Question 4

What manifestations of acute limb ischaemia suggest that preservation of the limb is unsalvageable?

Answer 4

Paralysis (loss of movement)

Parasthesia (loss of sensation)

Permanent mottling

Question 5

What are the main causes of acute limb ischaemia?

Answer 5

Thrombosis (40%): Rupture of atheroscleortic plaque

Embolism (40%): Typically AF

Vasospasm (e.g. Raynaud’s syndrome)

Extrernal vascular comprimise
- Trauma
- Compartment syndrome

Question 6

What is compartment syndrome?

Answer 6

Increase pressure inside a muscle which comprimises blood supply

Question 7

How does timing of symptoms differ in patients with thrombotic causes of acute limb ischaemia vs embolitic causes?

Answer 7

Thrombolysis:
Sub-acute onset
Signs of PAD typically seen in contralateral limb

Embolitic:
Acute onset
Typically caused by AF

Question 8

What investigations should be considered in patients suspected of having acute limb ischaemia?

Answer 8

Bedside:

ECG: Check for AF

Handheld arterial doppler examination: Absence of distal doppler signals suggestive of severe ischaemia

ABPI: Consider if doppler signals present

Bloods:

FBC

U&Es: Baseline function

Group and save: In case blood transfusion is needed for surgery

Clotting studies: Important for surgery prep

Question 9

What is the management plan for patients suspected of acute limb ischaemia?

Answer 9

ABCDE approach:

Oxygen if needed

IV fluids

Analgesia (IV opioids)

Urgently inform vascular surgery

Keep patient Nil by mouth for surgery

Senior review

IV unfractioned heparin (prevents thrombus propagation and given especially if surgery may be delayed)

Surgery:
Intra-arterial thrombolysis
Surgical embolectomy
Angioplasty
Bypass surgery
Amputation: for patients with irreversible ischaemia

Question 10

Definitive management of acute limb ischaemia depends on which factors?

Answer 10

Complete or incomplete limb ischaemia

Thrombotic cause or embolic cause

Question 11

If a patient has incomplete limb ischaemia and the limb is likely to be viable for 12-24 hours, what additional investigation should be done in preparation for surgery?

Answer 11

CT angiography: To identify location of occlusion and guide intervention

Question 12

What surgical options are best for patients with incomplete thrombotic ischaemia?

Answer 12

Angioplasty

Thrombectomy

Intra-arterial thrombolysis

Question 13

What is angioplasty?

Answer 13

Use of a baloon to strecth open a blocked or narrowed artery

Question 14

What is a thrombectomy procedure?

Answer 14

Procedure with the aim of removing a blood clot blocking an artery or vein

Question 15

What is intra-arterial thrombolysis?

Answer 15

Procedure involving direct administration of agents (plasminogen activators) which directly breakdown the clot

Question 16

What surgical option is best for patients with complete thrombotic limb ischaemia?

Answer 16

Urgent bypass surgery

N.B. Angiography and thrombolysis will delay management

Question 17

What surgical option is best for patients with embolic acute limb ischaemia?

Answer 17

Urgent embolectomy

Question 18

What is the surgical management for a patient with a non-viable limb?

Answer 18

Amputation