Vascular Surgery Flashcards
What are the 6 Ps of acute limb ischaemia?
Pale Pulseless Pain Paralysis Parasthesia Perishingly cold
What is the best management for acute limb ischaemia?
Surgical intervention
How is ABPI calculated?
ABPI = the highest pressure in either the posterior tibial artery or dorsalis pedis artery in ONE foot divided by the highest pressure in the brachial artery from either arm
What is acute limb ischaemia?
A sudden decrease in limb perfusion that is a potential threat to viability of the limb
How common is acute limb ischaemia?
Affects 1 in 6000 people
What are the 2 main pathophysiologies of acute limb ischaemia?
- Acute thrombosis of a vessel with pre-existing atherosclerosis
- Emboli
Name some other rare causes of acute limb ischaemia?
- Aortic dissection
- Trauma
- Iatrogenic injury
- Peripheral aneurysm (esp. popliteal)
- Intra-arterial drug use
What proportion of acute limb ischaemia is caused by acute thrombosis of an already atherosclerosed vessel?
60%
What factors predispose a patient to acute thrombosis -> acute limb ischaemia?
Dehydration Hypotension Malignancy Polycythaemia Inherited pro-thrombotic states
How do the majority of emboli form?
Cardiac causes e.g. AF, MI, ventricular aneurysm
Where are the common sites of impaction of an embolus?
Brachial artery
Common femoral artery
Popliteal artery
Aortic bifurcation
When does irreversible tissue damage occur to a limb?
After 6 hours of severe ischaemia
How is acute limb ischaemia managed initially?
Emergency management - give 100% O2, IV access and consider crystalloids if dehydrated, blood tests, CXR and ECG. Opiate analgesia, refer upwards.
What blood tests do we request for acute limb ischaemia?
FBCs U+Es Troponin Clotting Glucose Group and save
How can you assess limb viability?
Look for pulses, temperature, appearance of skin, limb power, sensation, and cap refill
How does irreversible limb ischaemia appear?
Fixed mottling of skin, petechial haemorrhages, wood hard muscles
How does limb ischaemia appear if it is saveable but needs immediate treatment?
Muscles tender to palpation, swollen, loss of power and loss of sensation
How is irreversible limb damage managed definitively?
Amputation
How is severe limb ischaemia (requires immediate treatment) managed definitively?
Prevent systemic complications of muscle necrosis (acidosis, hyperkalaemia, AKI).
Surgery to revascularise the limb + perform fasciotomy
Consider amputation
How is severe limb ischaemia (requires prompt treatment after investigation) managed definitively?
Heparinisation
Angiogram/Duplex/CT to determine location of disease
Thrombolysis
Surgery
Which limb does chronic ischaemia occur in most commonly?
Lower limb
What are the causes of chronic limb ischaemia?
Atherosclerosis
Arteriosclerosis
How do we classify lower limb ischaemia?
The Fontaine classification
What are the 4 levels of Fontaine classification?
I - asymptomatic
II - intermittent claudication
III - Rest pain
IV - Ulcers/Gangrene