Chronic limb ischaemia

Question 1

What are some of the causes of chronic limb ischaemia?

Answer 1

Atherosclerosis - asymptomatic until 50% stenosis

Vasculitis

Question 2

What are the modifiable risk factors for chronic limb ischaemia?

Answer 2

Smoking
BP
DM control
Hyperlipidaemia
Exercise

Question 3

What are the non modifiable risk factors for chronic limb ischaemia?

Answer 3

FH
PMH
Male
Increasing age
Genetic

Question 4

What vascular diseases are associated with chronic limb ischaemia?

Answer 4

IHD
Carotid artery stenosis
AAA
Renovascular disease
DM microvascular disease

Question 5

Define intermittent claudication

Answer 5

Cramping pain after walking a fixed distance, rapidly relieved by rest
Can be calf pain - superficial femoral disease, most common
Or buttock pain - Iliac disease (internal or common)

Question 6

Define critical limb ischaemia

Answer 6

Rest pain! (Especially at night, felt in foot. Due to decreased cardiac output + loss of gravity so patient will drop foot out of bed)
Ulceration
Gangrene

Question 7

What investigations can be done for a patient with chronic limb ischaemia?

Answer 7

Doppler US
ABPI (Ankle brachial pressure index)
Walk test
Bloods - FBC, U+Es, Glucose, Lipids, CRP, G+S
Imaging - Colour duplex US
ECG - ischaemic changes

Question 8

What is the normal doppler waveform?

Answer 8

Triphasic

Question 9

What is the doppler waveform in mild stenosis?

Answer 9

Biphasic

Question 10

What is the doppler waveform in severe stenosis?

Answer 10

Monophasic

Question 11

What diseases can give falsely high results in ABPI?

Answer 11

DM
Chronic renal failure
Due to calcification of vessels

Question 12

What is the management of chronic limb ischaemia?

Answer 12

Conservative - ↑exercise, wt loss, smoking cessation
Medical - Manage risk factors eg DM, BP, lipids. Give antiplatelets eg Clopidogrel, Aspirin. Pain relief
Surgical - Percutaneous Transluminal Angioplasty ± stenting (if severe or develop rest pain)