Limb Ischaemia Flashcards by Samii Ross

name the 3 types of acute limb ischaemia

acute
acute on chronic
critical

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a solid mass of platelets and/or fibrin that forms locally in a vessel in response to activation of the clotting system…

thrombus

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what makes an embolus different to a thrombus?

it is a piece of thrombus that has broken off and runs through vessels where it can cause blockages

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define acute limb ischaemia

a SUDDEN decrease in limb perfusion that threatens the viability of the limb

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ALI

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after how many hours will the leg appear mottled and blanch on pressure in ALI?

4-12

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patient presents with a white, painful foot with sensorimotor deficit as a result of ALI - how many hours ago did the injury occur?

0-4hrs

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how does DVT present differently to ALI?

DVT: hot and swollen
ALI: pale and pulseless (6 P’s)

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name the 6 P’s of limb ischaemia

pale
pulseless
paraesthesia
pain
pallor
paralysis

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DDx for acutely painful limb?

ALI
DVT
trauma - look for bony tenderness
neurological eg disc herniation

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patient with an acutely painful limb that is worse on movement and has diminished reflexes…

neuro cause eg disc herniation or radiculopathy

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associated Sx to ask about in vascular?

SoB
chest pain
palitations
numbness/tingling

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a PMH of what conditions puts the patient at more risk of ALI?

chronic LI
AF
MI
AAA
hypertension
hypercholesterolaemia
prosthetic heart valves

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most common cause of ALI?

embolism (usually from proximal location eg from AF/MI/AAA)

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how can a thrombus-in-situ cause acute limb ischaemia?

atheromatous plaque in the artery ruptures and a thrombus forms on the plaque’s cap which can occlude the artery

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ALI with a completely normal contralateral limb indicates the cause is…

an embolism

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a more proximal blockage in ALI will cause what clinical sign?

BOTH limbs affected

name the 3 main causes of ALI

embolism
thrombus in-situ
trauma

name traumatic causes of ALI

compartment syndrome
dissection
external compression

bloods for ALI?

FBC/U+E
LACTATE (++ in ischaemia)
thrombophilia screen
G&amp;S
Troponin and CK for MI

Ix ALI

bloods
ECG for MI/AF
ECHO if structural issue
CXR - smokers
Duplex USS - gold standard
CT angio

medical Mx ALI

high flow O2
IV access
antiplatelet + anticoagulant

surgical Mx embolic ALI

embolectomy via fogarty catheter

2. amputation

surgical Mx thrombotic ALI

thrombolysis
angioplasty
bypass surgery
amputation

mortality from ALI after treatment

10-30%

complications of ALI?

1. hyperkalaemia - ++ K from damaged muscle cells 2. acidosis - H+ release 3. AKI - + myoglobin release 4. reperfusion injury - can cause compartment syndrome

patient presents with pain that doesn't fit the clinical presentation, paraesthesia, paralysis and is worse on stretching. peripheral pulses are present. what's going on?

compartment syndrome

gold standard investigations for ALI?

duplex USS | ct angio

Tx compartment syndrome

fasciotomy

what is different on presentation in patients with AOCLI vs acute ALI?

they will have a PMH of claudication and PAD

most common cause of AOCLI

atheroembolic - small emboli released over time from existing arterial disease

Ix AOCLI

``` same as ALI: bloods ECG/ECHO/CXR duplex USS CT angio ```

surgical Mx AOCLI (if salvageable)

1. thrombectomy 2. angioplasty/stent 3. bypass

when pathologically would a limb be classified as having critical limb ischaemia (CLI)?

when the lumen is so narrowed that the requirements from distal muscles are higher than the blood supply available

symptoms of a patient with CLI?

1. severe claudication - can only walk 10m 2. rest pain >2 weeks that is worse at night 3. tissue loss

patients with CLI will have what clinical signs on examination?

+ve buerger's test absent peripheral pulses may have ulcers/ischaemic toes

what extra Ix is done for CLI and why

ABPI to show difference in blood flow

ABPI is

0.5

surgical Mx CLI

1. angioplasty 2. endarterectomy 3. amputation

what is buerger's test?

lift patients feet up and hold for 2 min. swing feet back down over the bed to see if they go pink again

what would be a sign of a positive buergers test?

feet blanch on elevation and go red again after swinging back over the bed