Ischaemic limb and occlusions

Question 1

what can acute limb ischaemia be referred to as

Answer 1

acute arterial occlusion

Question 2

what is acute limb ischaemia

Answer 2

occlusions in the arteries supplying the limbs cause ischaemia; decreased perfusion threatens the viability of the limb

Question 3

epidemiology of acute limb Ischemia

Answer 3

15 in 100,000 per year

Question 4

what are the 3 categories are causes of acute limb ischaemia organised into

Answer 4

embolisation (most common)
thrombosis in situ
trauma (less common)

Question 5

what is embolisation

Answer 5

where thrombus from proximal sources travel distally to occlude an artery

Question 6

what is thrombosis in situ

Answer 6

atheroma plaque in the artery ruptures and thrombus forms on the plaque cap

Question 7

risk factors for acute limb ischaemia

Answer 7

smoking, age, obesity, high cholesterol, sedentary lifestyle, diabetes mellitus, high blood pressure and family Hx of vascular disease

Question 8

presenting symptoms of acute limb ischaemia

Answer 8

6P’s;
pain, pallor, pulselessness (3 most common symptoms)
paresthesia, perishingly cold and paralysis

Question 9

difference between acute limb ischaemia and embolic occlusion

Answer 9

acute limb ischaemia is the sudden onset of the 6P’s whereas embolic occlusions present with a normal, pulsatile limb

Question 10

Rutherford classification summarised

Answer 10

I - viable
IIa - marginally threatened (salvageable if promptly treated)
IIb - threatened (salvageable if immediately revascularised)
III - irreversible

Question 11

differential diagnoses for acute limb ischaemia

Answer 11

chronic limb ischaemia, DVT, peripheral nerve compression or spinal nerve compression

Question 12

investigations

Answer 12

routine bloods (look out for lactate)
ECG
Doppler ultrasound followed by CT angiography

Question 13

what scan would you do if the limb is salvageable

Answer 13

CT arteriogram; can determine location of occlusion

Question 14

is acute limb ischaemia a surgical emergency

Answer 14

yes. complete arterial occlusion will lead to irreversible damage within 6 hours

Question 15

initial management of acute limb ischaemia

Answer 15

surgery (if Rutherford IIb)
start patient on hi flow oxygen and ensure IV access. administer therapeutic dose of heparin plus bolus dose via a heparin infusion

Question 16

for which patients is conservative management suitable

Answer 16

Rutherford I or IIa

Question 17

what is conservative management

Answer 17

prolonged course of heparin

Question 18

how do you know if heparin is working in conservative management? what to do if it’s not?

Answer 18

monitor their APPT time. if no improvement, prepare for surgery

Question 19

if cause is embolic, what surgery options are available

Answer 19

embolectomy via Fogarthy catheter
local intraarterial thrombolysis
bypass surgery

Question 20

if cause is thrombosis, what surgery options are available

Answer 20

local intraarterial thrombolysis
angioplasty
bypass surgery

Question 21

if patient is Rutherford III, what do you do

Answer 21

irreversible damage requires urgent amputation

Question 22

long term management (reducing risk of CVD)

Answer 22

smoking cessation, weight loss and regular exercise

Question 23

long term management (meds)

Answer 23

either anti platelet drugs (aspirin or clopidogrel)

or anticoagulation therapy (warfarin of DOAC)

Question 24

management of patient that has had an amputation

Answer 24

long term rehabilitation plan, occupation therapy and physiotherapy