Acute limb ischaemia

Question 1

What are the different severities of limb ischaemia?

Answer 1

Incomplete
Complete
Irreversible

Question 2

Define incomplete limb ischaemia

Answer 2

Limb not threatened

Question 3

Define complete limb ischaemia

Answer 3

Limb threatened

- Loss of limb unless intervention within 6hrs

Question 4

Define irreversible limb ischaemia

Answer 4

Requires amputation

Question 5

What are the causes of acute limb ischaemia?

Answer 5

Thrombosis in situ
Embolism
Graft/stent occlusion
Trauma
Aortic dissection

Question 6

What are the causes of Thrombosis in situ?

Answer 6

A previously stenosed vessel with plaque rupture

• Usually causes incomplete ischaemia
• Most common cause of acute limb ischaemia

Question 7

What may cause an Embolism?

Answer 7

80% from left atrium in AF
Valve disease
Iatrogenic from angioplasty/surgery
Fat embolism in long bone fracture
- Often complete limb ischaemia

Question 8

Where do emboli commonly lodge?

Answer 8

At the femoral bifurcation

Question 9

What are the 6 P’s for the presentation of limb ischaemia?

Answer 9

Pale - Marble white, mottling that blanches
Pulseless
Perishingly cold
Painful
Paraesthesia
Paralysis

Question 10

What is the presentation of acute limb ischaemia due to thrombosis in situ?

Answer 10

Onset over hours - Days
Less severe ischaemia due to collateral circulation
History of claudication
Absent contralateral pulses

Question 11

How do you diagnose acute limb ischaemia due to thrombosis in situ?

Answer 11

Angiography

Question 12

What is the treatment of acute limb ischaemia due to thrombosis in situ?

Answer 12

Emergency reconstruction if complete
Angiography + angioplasty, bypass surgery
Thrombolysis
Amputation

Question 13

What is the presentation of acute limb ischaemia due to embolism?

Answer 13

Sudden onset
Profound ischaemia
Embolic source often still present
No history of claudication
Contralateral pulses present

Question 14

How do you diagnose acute limb ischaemia due to embolism?

Answer 14

Clinical diagnosis - History and examination

Question 15

What is the treatment of acute limb ischaemia due to emboli?

Answer 15

Embolectomy - send emboli for histolological assessment to exclude atrial myxoma
Thrombolysis - If embolectomy unsuccessful, local injection of tissue plasminogen activator (TPA)
Other - Warfarin, Amputation, Emergency reconstruction

Question 16

What investigations can be done in a patient with suspected acute limb ischaemia?

Answer 16

Bloods - FBC, U+Es, Group+Save, INR, Creatinine kinase
ECG
Imaging - CXR, Duplex doppler

Question 17

What is the general management of acute limb ischaemia?

Answer 17

Discuss with a senior 
Nil by mouth
Rehydration - IV fluids
Analgesia - morphine (up to 10mg/4 hours) + metoclopramide
Abx if signs of infection
Unfractionated heparin
*Manage CV risk*

Question 18

What is the treatment for a patient with complete occlusion acute limb ischaemia?

Answer 18

Urgent surgery - embolism or bypass

Question 19

What is the treatment for a patient with a partial occlusion acute limb ischaemia?

Answer 19

Angiogram + observe for deterioration

Question 20

What is the management post embolectomy in a patient who had acute limb ischaemia?

Answer 20

Anticoagulation (heparin changed to warfarin long term)

Identify the embolic source - ECG, Echo, US aorta femoral + popliteal arteries

Question 21

What are the complications post embolectomy?

Answer 21

Reperfusion injury - local swelling; may case compartment syndrome, Acidosis + Arrhythmias secondary to ↑K, Acute respiratory distress syndrome.
Chronic pain syndromes