acute arterial ischemia and vascular trauma

Question 1

what is acute limb ischaemia ?

Answer 1

a sudden decrease in limb perfusion

Question 2

what does the effect of sudden arterial occlusion depend on ?

Answer 2

size of the blood vessel occluded and the state of the collateral blood flow

Question 3

what is the aetiology of acute limb ischaemia ?

Answer 3

acute embolic ischaemia
acute thrombotic ischaemia
acute traumatic ischaemia

Question 4

where are we more likely to find an acute embolus causing ischaemia ?

Answer 4

at arterial bifurcation
whether aortic, iliac , femoral or popliteal

Question 5

what is the difference between embolic and thrombotic ischaemia ?

Answer 5

with embolic ischaemia a relatively healthy artery is affected whereas thrombotic there is already an underlying pathology

Question 6

what are the consequences of having an embolus in each of these organs ?
brain
retina
mesenteric vessels

Answer 6

brain - TIA or stroke
Retina- Amaurosis fugax or permanent blindness
mesenteric vessels- intestinal angina or intestinal gangrene

Question 7

when is claudication pain present ?

Answer 7

claudication pain is only present with thrombosis

Question 8

what are the risk factors for acute embolic occlusions ?

Answer 8

atrial fibrillation
recent AMI
prosthetic heart valves

Question 9

what are the risk factors for acute thrombotic occlusions ?

Answer 9

no specific risk factors but the blood vessels are diseases (underlying pathology)

Question 10

what is the clinical presentation for acute limb ischaemia ?

Answer 10

pain 
paralysis 
pulseless 
perishingly cold 
pallor 
paraesthesia

Question 11

in terms of colour changes what are the differences in late and early stages of acute limb ischaemia ?

Answer 11

early –> pale in colour

late –> cyanosed then mottling then fixed mottling and cyanosis

Question 12

what does the loss of motor function indicates ?

Answer 12

indicates advanced limb threatening ischaemia

Question 13

what is an indication of late irreversible ischaemia ?

Answer 13

muscle turgidity

Question 14

which muscles are first affected with acute limb ischaemia ?

Answer 14

intrinsic foot muscles followed by the leg muscles

Question 15

why is it difficult to detect early muscle weakness ?

Answer 15

because toe movements are produced mainly by leg muscles

Question 16

what does poikilothermic mean ?

Answer 16

when the limb acquires the temperature of the surroundings due to the lack of perfusion

Question 17

what is the staging of acute limb ischaemia ?

Answer 17

I: Viable
IIA: Marginally threatened
IIB: immediately threatened
III: Irreversible

Question 18

in which stage of acute arterial ischaemia would there be rest pain ?

Answer 18

stage IIB where the limb is immediately threatened

Question 19

what kind of investigations would you carry out ?

Answer 19

doppler/duplex ( duplex not so much routine)
angiography ( CTA/MRA) –> CTA is the first line
digital subtraction angiography

Question 20

which imaging modality would be avoided with patients with limited renal function ?

Answer 20

avoid CTA , perform MRA

Question 21

what are the goals of therapy with acute ischaemia ?

Answer 21

prevention of propagation
restoration of blood flow
preservation of the limb
prevention of recurrence

Question 22

what is the immediate management with ALI ?

Answer 22

give the patient IV heparin and analgesia

Question 23

what would the management options acordingto the stagging of the ritheford clasaification ?

Answer 23

stage I- imaging
Stage IIa- imaging
stage IIb - imaging if no delay
stage III- amputation

Question 24

what are the methods of revascularization ?

Answer 24

thromboelectomy
catheter directed thrombolysis
endovascular techniques
bypass surgery

Question 25

what are some simple measure that can be taken to improve existing perfusion ?

Answer 25

``` keep the foot dependent avoid pressure over the heel avoid extremes of temperature maximize tissue oxygenation correct hypotension start treatment of any other associated conditions ```

Question 26

how would we intervene in a case of embolic occlusion ?

Answer 26

embolectomy using a Fogarty catheter , an arrteriotomy through the common femoral artery ( balloon and catheter)

Question 27

how would you intervene in the case of an acute thrombotic occlusion ?

Answer 27

first perform an arteriogram then for intervention: a long segment occlusion - surgical bypass short segment occlusion - thrombolytic therapy then we can perform either balloon angioplasty or vascular bypass

Question 28

what intervention could be performed with traumatic vascular disease ?

Answer 28

end to end anastomosis with autologous vein graft

Question 29

what are the possible complications following intervention?

Answer 29

- reperfusion syndrome - recompartment syndrome - catheter related

Question 30

what are the complications of reperfusion injury ?

Answer 30

``` myocardial injury remote lung injury renal injury gastrointntestinal compartment syndrome ```

Question 31

what is the treatment for compartment syndrome ?

Answer 31

urgent fasciotomy to release the compression

Question 32

what are the mechanisms of vascular trauma ?

Answer 32

blunt penetrating iatrogenic

Question 33

what are the hard signs?

Answer 33

``` absent or diminished distal pulses active haemorrhages expanding hematoma bruit distal ischaemia ```

Question 34

what are the soft signs ?

Answer 34

``` small, stable hematoma injury to anatomically related nerve unexplained hypotension Hx of haemorrhages proximity of injury to major vessel ```

Question 35

what are the myocardial depressant factors ?

Answer 35

C3a TxA2 LTD4

Question 36

when is the best time of management ?

Answer 36

within the first 6 hours

Question 37

what is the gold standard of investigation ?

Answer 37

Angiography

Question 38

what are the different sources of embolism ?

Answer 38

cardiac sources - left atrium in atrial fib, mural thrombus in MI, endocarditis, valvular disease arterial sources - aneurysm, atherosclerotic plaque, aneurysm paradoxical

Question 39

what are the sources off thrombosis ?

Answer 39

atherosclerosis vascular graft thrombosis of an aneurysm entrapment syndrome hypercoaguable state low flow state

Question 40

what manoeuvre is completely contraindicated in acute limb ischemia ?

Answer 40

raising the leg