Arterial disease of the limbs Flashcards
\what causes normally causes critical limb ischaemia ?
Atherosclerotic disease of the arteries supplying the lower limb
What are some less common causes of critical limb ischaemia?
Vasculitis
Buerger`s disease
What is the classification of CLI?
Fontaine Classification
What is stage 1 CLI?
Asymptomatic, incomplete blood vessel obstruction
What is stage 2 CLI?
Mild claudication pain in limb
a) when walking greater than 200m
b) When walking a distance of less than 200m
What is stage 3 CLI?
Rest pain, mostly in feet
Stage 4 CLI?
Necrosis and/or gangrene of the limbs
What are the signs of chronic iscahemia in the limbs?
Ulceration
Pallor
Hair loss
What should be done when examining for CLI?
(Start at toes and compare)
- Capillary refill times
- Temperature
- Pulses-start at aorta
- Peripheral sensation
What pulses should be auscultated?
- Dorsalis pedis
- Posterior tibial
What are the two special tests used when examining for CLI?
- Ankle Brachial pressure Index
2. Buerger`s test
How do you measure the ankle brachial pressure?
Ankle pressure
divided by
Brachial pressure
How do you carry out Buergers test?
elevate legs
-pallor
in less than 20 degrees= severe ischaemia
Hang feet over bed
-Slow to regain colour
-Dark red colour
(hyperaemic sunset foot)
What fraction of capillaries are normally open in the leg?
1/3
How should patients with Peripheral vascular disease be managed?
The same way as those with CHD
What is the best medical therapy for PVD?
- Anti-platelets
- Statin
- Bp control
- Smoking cessation
- Exercise
- Diabetic control
How do antiplatelets help PVD?
Reduce risk of requiring re-vascularisation as well as reducing cardio and all cause mortality
How do Statins help PVD?
inhibits platelet activation and thrombosis, endothelial and inflammation activation, plaque rupture
What is the target for BP?
<140/85
When does excess risk of cardiovascular disease diminish after smoking cessation?
4-6 yrs
What percentage of Peripheral artery disease patients are undiagnosed diabetics?
10%
What is added to BMT when symptoms are severe?
Angioplasty/stent/surgical bypass
What is added to BMT when symptoms are critical?
Angioplasty/stent/endovascular reconstruction/surgical bypass/stent
What are the advantages of Ultrasound?
- No radiation
- Dynamic
What are the disadvatages of ultrasound?
- Not good in abdomen
- Operator dependant
What are the advantages of CT/MRI?
- Detailed- allows treatment
- First line according to NICE
What are the disadvantages of CT/MRI?
- Contrast radiation
- Can overestimate calcification, difficulty in low flow states
What happens in a digital subtraction angiogram?
needle is placed in artery and fluorescent dye is deposited
what does surgical bypass require?
-Inflow
A conduit (autologous,synthetc)
-Outflow
What is the risk of complications with surgical bypass?
- General; bleeding, infection,pain,scar DVT,PE,MI,CVA,LRTI,Death (2%)
- Technical :damage to nearby vein,artery, nerve,distal emboli,graft failure
Define an emboli?
A blood clot, air bubble, peice of fatty deposit, or other object which has been carried in the bloodstream to lodge in a vessel and cause embolism?
Define a thrombus?
A blod clot formed in situ within the vascular system of the body and impeding flow
What causes an arterial embolus?
-MI,AF,proximal atherosclerosis
What causes thrombosis?
usually thrombosis of a previously deceased artery
What are the six Ps of CLI?
- Pain
- Pallor
- Perishingly cold
- Paraesthesia
- Paralysis
- Pulseless
What is paraesthesia?
abnormal sensation, typically tingling or pricking (‘pins and needles’), caused chiefly by pressure on or damage to peripheral nerves.
What happens in muscle compartment syndrome?
- Muscle ischaemia
- inflammation
- oedema
- Venous obstruction
Tense and tender calf
rise increatine kinase
Risk of renal failure
When oedema occurs what happens?
venous system will not be able to drain
Amputation
How do you manage ALI?
ECG bloods, nil by mouth
-analgesia anticoagulants
What percentage of acute limb ischaemia is embolic and thrombosis in situ?
- 30%
- 60%
What is the mortality rate of acute limb ischaemia?
22%
How many diabetics will develop a foot ulcer in their lifetime?
15%
What is the pathophysiology of a foot ulcer?
- Microvascular peripheral artery disease
- Peripheral neuropathy
- Mechanical imbalance
- Suceptibility to infection
What foot care should be adhered to when foot ulcers can develop?
- Always wear shoes
- Check fit of footwear
- Check pressure points/plantar surface of foot regularly
- prompt and regular woundcare of skin breaches
What is the management of diabetic foot disease?
-revascularisation
=Disease is very distal
=distal bypass
-Amputation
