Arterial Disease of the Limbs Flashcards
What are the five pulses you can feel below the waist and where would you find them?
Aorta (above umbilicus, use two hands to feel for pulsation vs expansion)
Common femoral (mid-inguinal point)
Popliteal (popliteal fossa)
Posterior tibial pulse (next to medial malleolus)
Dorsalis pedis - between first two metatarsals of foot.
What is the main cause of chronic limb ischaemia?
Atherosclerotic disease of arteries supplying the lower limb.
What are some rare causes of CLI?
Vasculitis - swelling of BVs, caused by leukocyte migration.
Burger’s disease - BVs become inflamed and swell and can be blocked with thrombi.
What are the risk factors for developing atherosclerotic disease?
Male, age, smoking, hypercholesterolaemia, hypertension and diabetes.
How are the symptoms of CLI related to the level of arterial blockage?
The more blocked the arteries the worse the symptoms will be.
What is the Fontaine classification?
Used to mark severity of symptoms of CLI.
What are the four stages of Fontaine classification?
1 - asymptomatic, incomplete BV obstruction
2 - mild claudication
2A - claudication when walking more than 200m
2B - claudication when walking less than 200m
3 - rest pain, mostly in feet
4 - necrosis, and/or gangrene of limb
What kinds of question would you need to ask about claudication?
Exercise tolerance, effect of incline, change over time, relieved by rest? Where in leg, type of pain.
What should you ask about rest pain?
Type of pain and relieving factors.
What kinds of question would you need to ask about tissue loss?
Duration, history of trauma, peripheral sensation.
What signs would you look for in chronic limb ischaemia on the lower limbs?
Ulceration, pallor and hair loss.
What things would you examine in the feet?
Capillary refill times, temperature, pulses, peripheral sensation (esp. in diabetics).
What is a doppler?
Machine that uses US to determine blood flow through arteries and veins.
Where would you use the hand held doppler?
Dorsalis pedis and posterior tibial pulses.
What is the ankle brachial pressure index?
ankle pressure/brachial pressure
Can determine clinical status and relates to the symptoms felt by the patient.
How do the symptoms worsen in CLI?
Goes from symptom free, to intermittent claudication, rest pain and then to gangrene and ulceration.
What special test might you want to carry out if you suspect CLI?
Buerger’s test
How do you perform Buerger’s test?
Raise leg and if pallor before 20 degrees elevation then severe ischaemia.
Hang feet over edge of bed, see if slow to regain colour or if go dark red colour (hyperaemic sunset foot).
What causes hyperaemic sunset foot?
Because in CLI autregulation is lost and all the capillaries are open (normally a third are open).
How should patients with PVD be managed?
The same as those with CHD.
What is the best medical therapy in CLI?
Antiplatelet - reduces risk of requiring revascularisation as well as reducing cardiovascular and all-cause mortality.
Statin - inhibits platelet activation and thrombosis, endothelial inflammation activation and plaque rupture.
BP control - target is less than 140/85.
Smoking cessation - excess risk of CV disease diminishes within 4-6 yrs.
Exercise - 150% improvement in walking time.
Diabetic control - 10% of PAD patients are undiagnosed diabetics. Tight glycaemic control prevents microvascular disease.
How would you treat mild/moderate CLI?
BMT only.
How would you treat moderate/severe CLI?
BMT
Angioplasty/stent, surgical bypass.
How would you treat severe/critical CLI?
BMT, angioplasty/stent, endovascular reconstruction, surgical bypass/stent.
What four imaging techniques can be used in diagnosis of CLI?
Duplex
CTA/MRA
Digital subtraction angiogram
What are the pros and cons of duplex?
Pros - dynamic and no radiation/contrast
Cons - not good in abdomen, operator dependent, time consuming
What are the pros and cons of CTA/MRA?
Pros - detailed, allows treatment planning, first line according to NICE
Cons - contrast and radiation, can overestimate calcification, difficulty in low flow states
What is angiography?
Injecting of dye into arteries for imaging.
When would you carry out a surgical bypass?
To try and supply blood to an area that is normally supplied by an occluded artery.
What three things does surgical bypass require?
Inflow
A conduit (vein from legs, arms, or synthetic PTFE/Dacron)
Outflow
What are some complications of the bypass surgery?
General - bleeding, wound infection, pain, scar, DVT, PE, MI, CVA, LRTI, death (2%).
Technical - damage to nearby vein, artery, nerve, distal emboli, grant failure (stenosis, occlusion).
What are some complications of the bypass surgery?
General - bleeding, wound infection, pain, scar, DVT, PE, MI, CVA, LRTI, death (2%).
Technical - damage to nearby vein, artery, nerve, distal emboli, graft failure (stenosis, occlusion).
What are re-intervention and 5yr patency rates like with surgical bypass procedures?
Re-intervention rate - 18.3-38.8%
5yr patency rates 45-73%
Name some lower limb amputations.
Hindquarter Hip disarticulation Above knee Through knee Below knee Symes Transmetatarsals Digit
What is the motility of BKA and AKAs?
Inside - 80% BKA, 40% AKA
Outside - 65% BKA, 43% AKA
How are energy requirements affected by below and above knee amputees?
63% increase in BKA
117% increase in AKA
How does acute limb ischaemia differ from CLI?
???
What is an embolus?
A blood clot, air bubble, piece of fatty deposit, or other object which has been carried in the bloodstream to lodge in a vessel and cause an embolism.
What is a thrombus?
A blood clot formed in situ within the vascular system of the body impeding flow.
What is the pathophysiology of ALI?
Arterial embolus: MI, AF< proximal atherosclerosis (not DVT/PE)
Thrombosis - usually thrombosis of a previously diseased artery
Trauma
Dissection
Acute aneurysm thrombosis, i.e. popliteal
What are the important things in history taking when you suspect ALI?
History of CLI Risk factors for CLI Cardiac history Onset/duration of symptoms Functional status/SH
What are the 6 Ps in presentation of ALI?
Pain, pallor, perishingly cold, paraesthesia, paralysis, pulseless
Always compare to contralateral limb.
When do the effects of ACI become irreversible?
After 6-8 hours of onset of symptoms.
What is compartment syndrome?
Bleeding/swelling within an enclosed muscle compartment which causes the pressure within a compartment to increase, restricting blood flow which may lead to nerve and muscle damage.
What are the results of compartment syndrome?
Muscle ischaemia, inflammation, oedema, venous obstruction.
What symptoms are felt in compartment syndrome?
Tense, tender calf.
What organ may fail in compartment syndrome?
Kidneys (myoglobulinaemia)
What levels may be high in the body during compartment syndrome and why is this?
Creatinine kinase, due to muscle necrosis.
How is ALI managed?
ECG, bloods, nil by mouth
Analgesia, anticoagulate (heparin - makes blood thinner, any chance of getting blood through it needs to be thinner).
If the limb is salvageable and there is suspicion of embolus only what course of action do you take?
Embolectomy
If the limb is salvageable and there is suspicion of thrombosis in situ, what two courses of action might you take?
Endovascular mechanical thromboectomy, thrombolysis.
or
Open embolectomy with or without bypass.
If the limb is not salvage what course of action must you take?
If patient is willing for amputation - amputate, if not or amputation not possible then palliate.
Embolectomy can be done under what kind of anaesthetic?
GA/LA
How many diabetics will develop a foot ulcer in their lifetime?
15%.
What are the pathophysiologies of diabetic foot disease?
Microvascular peripheral artery disease
Peripheral neuropathy
Mechanical imbalance
Susceptibility to infection
How can diabetics prevent foot disease?
Always wear shoes
Check fit of footwear
Check pressure points/plantar surface of foot regularly
Prompt and regular wound care of skin breaches
How can we manage diabetic foot disease?
Prevention
Good wound care
Tracking infection - consider systemic antibiotics
Investigate for osteomyelitis, gas gangrene, necrotising fasciitis.
What is a sign of necrotising fasciitis?
Gas in tissues.
If foot disease is very distal what can be attempted?
Revascularisation
Distal crural angioplasty/stent
Distal bypass
What the last line of action with diabetic foot disease?
Amputation