Arterial disease of the limbs Flashcards
Where is the aortic pulse felt?
Above umbilicus
Where is the common femoral artery pulse felt?
Mid-ingunal point - halfway between pubic symphysis and superior iliac spine
Where is the popliteal artery pulse felt?
Deep in popliteal fossa of knee
Where is the posterior tibial pulse felt?
halfway between medial malleolus and the achilles tendon
Where is the dorsal is pedis pulse felt?
Lateral to the extensor hallucis longus tendon
What can cause critical limb ischaemia?
Atherosclerosis
Vasculitis
Buergers disease
What is buergers disease?
Inflammation of vessels, which then get blocked with clots
What are the risk factors for critical limb ischaemia?
Male Age Smoking Hypercholesterolaemia Hypertension Diabetes
How do we classify critical limb ischaemia?
Fontaine classification
I - asymptomatic IIa - mild claudication walking >200m IIb - mild claudication <200m III - pain at rest, mostly in feet IV - necrosis and/or gangrene
What in a patient history is necessary for CLI diagnosis?
Claudication - leg out of bed at night Rest pain Tissue loss Risk factors PMH Drug history - anti platelets, statins, diuretics SH - smoking OH - take into account the deciding treatment
What are some physical signs of critical limb ischaemia?
Ulceration Pale pallor Hair loss Cool to touch Decreased peripheral pulses Loss of peripheral sensation Decreased capillary refill times
What special tests can be used to diagnose CLI?
Ankle brachial pressure index
Buergers test - elevate and lower legs and note pallor
Why in CLI do patients have hyperaemic sunset foot following the Buerger test?
Autoregulation is lost, leading to all capillaries filling rapidly to cause flush
What medical therapy is offered to those with CLI?
Antiplatelets Statins BP control <140/85 Smoking cessation Diabetic control Angioplasty CABG Amputation if too severe
What investigations are used for CLI?
Duplex ultrasonography
CTA
MRA
Digital subtraction angiogram (not often used now)
What are the pros of duplex ultrasonography?
Dynamic
No radiation/contrast
What are the cons of duplex ultrasonography?
Not clear in the abdomen
Operator dependent
time consuming
What are the pros of MRA/CTA?
Detailed
What are the cons of MRA/CTA?
Contrast and radiation used
Can overestimate calcification
Difficult in low flow states (occlusion)
What is potency?
Degree of openness of a vessel
What is required for a surgical bypass?
Adequate inflow
An available conduit/graft
Clear outflow path
What are some complications of surgical bypass surgery?
Bleeding Infection of wound Pain Scar DVT/PR/MI/CVA Death Damage to nearby anatomy Graft failure Graft infection
How does acute limb ischaemia present?
History of CLI and claudication
Onset of symptoms over 6 hours
Compartment syndrome
What are the 6 Ps?
Pain Pallor Perishingly cold Paraesthesia (abnormal sensations) Paralysis Pulseless
When does acute limb ischaemia damage become irreversible?
> 6 hours since onset of symptoms
What is compartment syndrome?
Increased pressure within one of the bodies compartments which contain muscles and nerves
What are the 2 types of compartment syndrome?
acute - occur after trauma
chronic external - exercise induced
What can cause compartment syndrome?
Trauma
Following attempt to revascularise tissue
Muscle cant drain, build up of pressure, feels tight and occluded blood flow, leading to ischaemia and possibly necrosis
How do you treat acute limb ischaemia?
ECG, blood tests, nil by mouth
Analgesia and anticoagulants
If severe:
Amputation
Embolectomy
What % of ALI is caused by emboli?
30%
What % of ALI is caused by thrombosis?
60%
What % of DM patients will develop a foot ulcer in their lifetime?
15%
How can we prevent diabetic foot disease?
Footcare Glycaemic control Regular checks Education Good wound care
What is one of the most common foot deformities seen in diabetic patients?
“Rocker bottom foot” - prominent calcaneus (heel bone) and convex sole of the feet
What causes diabetic foot disease?
Microvascular peripheral artery disease
Peripheral neuropathy
Mechanical imbalance
Infection by commensals
What should you also investigate for in suspected cases of diabetic foot disease?
Osteomyelitis
Gas gangrene
Necrotizing fascitis
How do we treat diabetic foot disease?
Revascularization (not very successful)
Amputation
