Limb ischaemia

Question 1

Presentation of acute limb ischaemia

- 6Ps

Answer 1

6Ps

• Pale
• Pulseless
• Perishing Cold
• Paraestheic/ anaesthetic
• Paralysed
• Pain

Question 2

Causes of acute limb ischaemia

Answer 2

Most common= embolus

• Most commonly from AF
• Clot from:
• Emboli can also be air/ foreign object
• Clot typically dislodges at arterial bifurcations

Acute on chronic
- Thrombus dislodging from atherosclerotic, stenosed plaque

Aortic dissection

Popliteal aneurysm

Iatrogenic
- Graft/stent occlusion

Question 3

Acute limb ischaemic definition

Answer 3

Onset of ischaemia in <14 days

Classifications

• Incomplete= limb not threatened
• Complete= limb threatened, loss of limb unless intervention within 16 hours
• Irreversible= Requires amputation/ palliative care

Question 4

Typical locations of emboli lodgings in limb ischaemia

Answer 4

Arterial bifurcations

• Popliteal
• Femoral (most common for embolism)
• Aortic

Question 5

Investigations for acute ischaemia

Answer 5

Bloods

• FBC, UEs
• Clotting
• CK
• G+S

ECG- rule out AF, if rapid cardiogenic intervention required first

Imaging

• Gold standard= CT angio
• Duplex doppler
• CXR

Question 6

Management of acute ischaemia

Answer 6

1. Anticoagulation
   - IV Unfractionated heparin
   - Then switch to warfarin/ DOAC

? Thrombolysis- streptokinase

2. Fluids, analgesia
3. Surgery =endarterectomy/ bypass
   - Transverse incision
   - Fogarty cathether
   - Bypass if clot is very long
   - Amputation if tissue cannot be salvaged.

Question 7

Embolectomy

• Analgesia
• Method
• Complications

Answer 7

Can be local or general
- Local is indicated for very elderly/ ill

Method

• Open: endarterectomy, transverse incision to prevent constriction of vessel
• Endovascular: fogarty catheter method, with balloon angioplasty

Complications
- Compartment syndrome (resolved with fascitomy)

Question 8

Chronic ischaemia

• Definition
• Causes

Answer 8

Ischaemia that is symptomatic >14 days

Causes
- Atherosclerosis: dyslipidaemia, HTN, diabetes.

Question 9

Chronic ischaemia

- Presentation

Answer 9

Claudication
- Intermittent pain, usually in calf relieved after resting.

Pain is nocturnal, can be persistent when severity worsens

Tissue loss/ ulcers
- Especially on pressure areas

Necrosis/ gangrene

Question 10

Chronic ischaemia

- Management

Answer 10

Reducing risk factors

• Increase physical activity
• Control BP
• STOP SMOKING
• cholesterol control: good diet, possibly statins
• Weight loss
• Anticlot: aspirin, clopidogrel 75mg

Surgery
- Open vs endarterectomy

Question 11

Examination of critically ischaemic leg

Answer 11

Appearance

• Raise leg= pale
• Mottled
• Hang leg= very reg due to autonomic arterial vasodilation

Blood pressure
- Ankle and arm BP= calculate ABPI

Question 12

ABPI

Answer 12

Ankle-brachial pressure index

Ratio between ankle:arm

• Around 1= normal, may be falsely high in calcified arteries (diabetes)
• <0.5= critically ischaemic

Question 13

Constrast contraindications/ cautions

Answer 13

Renal failure, poor eGFR

Allergy/ sensitivity

Myeloma

Poor hydration

Question 14

Claudication

• Definition
• Risk factors

Answer 14

Pain onset in leg after walking

• Relieved by rest
• Commonly in calves, can radiate to glutes.

Due to narrowing of arteries causing muscle ischaemia.

Risk factors

• Smoking
• Age
• Diabetes
• Family history
• HTN, hyperlipidaemia

Question 15

Claudication

- Prognosis

Answer 15

Increased mortality rate

Increased risk of cardiovascular event

Question 16

Claudication

- treatment

Answer 16

Reduce risk factors

• As with ischaemia
• antiplatets, antihypertensives, statins.

Increase activity (supervised exercise)
- Stimulates collateralization, alternate blood supply

Revascularization as absolute last resort

Question 17

Claudication vs neurogenic

Answer 17

Walking up hill makes vascular claudication worse

Neurogenic cause
- Worse pain when walking down as foramina is compressed