Peripheral Arterial Disease Flashcards
what happens in pAD?
atherosclerosis causes stenosis of the arteries via multifactoral processes involving modifiable and nonmodifiable risk factors
As with CAD ___ _____ is responsible for the most serious manifestations of PAD and not infrequently occurs in a ____ that has been hitherto asymptomatic.
. As with CAD plaque rupture is responsible for the most serious manifestations of PAD and not infrequently occurs in a plaque that has been hitherto asymptomatic.
what are the symptoms of chronic PAD?
- intermittent claudication
- severe PAD - may experience ulceration, gangrene and foot pain at rest
- rest pain can result in the patient being unable to sleep, this is relieved by hanging the foot out the bed
what is interittent claudication?
This is the ischaemic pain affecting the muscles of the leg upon walking.
what are the characteristics of IC?
- Often the pain is worse walking uphill but never occur at rest
- the distance walked until intermittent claudication sets in never changes
- The pain is usually in the calf
calf claudication suggests ____ disease while buttock claudication suggests ____ disease
calf claudication suggests femoral disease while buttock claudication suggests iliac disease
fontaine classification of PAD 1-4
1 - asymptomatic
2 - IC
3 - ischaemic rest pain
4 - ulceration/ gangrene (critical ischaemia)
what are the signs of PAD?
- The lower limbs are cold with dry skin and lack of hair
- diminished or absent femoral, popliteal or foot pulses
- pallor
- postural dependent colour change
- punched out ulcers - often painful
- long capillary refill time
what are the common risk factors for PAD?
smoking, diabetes, hypercholesterolaemia, hypertension
what tests are done to assess risk factors?
FBC, U & E, lipids, ECG, thrombophilia screen and serum homocysteine
what diseases are excluded by ESR/CRP?
diabetes, arthritis
why do a FBC ?
for anaemia and polycythaemia
why do a U&E
for renal disease
why do liipds?
for dyslipidaemia
why do an ECG?
to assess for cardiac disease
what test is used to assess BP at the ankle?
ankle brachial pressure index
what is the ABPI?
This is a measurement of the cuff pressure at which the blood flow is detectable by doppler in the posterior tibial or anterior tibial arteries compared to the brachial
what is the normal ABPI range?
1-1.2
what is the PAD range of ABPI?
0.5-0.9
what is the ABPI range for critical ischaemia ?
less than 0.5 or ankle systolic pressue of less than 50 mmHg
what can give falsely high ABPI readings?
if the patient has calcification of the arteries (atherosclerosis) - as they are incompressible
what disease may give incompressible arteries?
renal or diabetic disease
ABPI=
ankle pressure /brachial pressue (both systolic)
what is the first line imaging technique ?
colour duplex - gives an assessment of the severity of the disease
what imaging is done if intervention is being considered?
MR/CT angiography - they are used to assess the extent and location of stenoses and quality of distal vessels
what areas are involved in management? 5
- risk factors
- management of claudication
- percutaneous transluminal angioplasty
- surgical reconstruction
- amputation
what areas should be treated - risk factors
- stop smoking
- diabetic management
- hypercholesterolaemia treated
- treat hypertension
what should be prescribed to prevent progression and reduce CV risk?
antiplatelet- clopidogrel 1st line
what is involved in intermittent claudication management ?
supervised exercise programmes
what does exercise do to improve IC?
reduces symptoms by improving collateral blood flow
what is the downside to exercise management?
in order to keep up the exercise tolerance it needs to be done regularly so you are putting yourself through pain regularly
what is an alternative to exercise management for those who do not wish to undergo vascularisation and if exercise fails to improve symptoms?
vasoactive drugs e.g. naftidrofuryl oxalate, offer modest benefit
what is the first option for intervention?
percutaneous transluminal angioplasty
Percutaneous transluminal angioplasty: this is the first option and is carried out via a catheter.
It is used for disease limited to a ____ arterial segment ( a balloon is inflated to the narrowed segment
Percutaneous transluminal angioplasty: this is the first option and is carried out via a catheter.
It is used for disease limited to a single arterial segment ( a balloon is inflated to the narrowed segment
when would surgical reconstruction be considered?
If atheromatous disease is extensive but distal run -off is good (i.e. distal arteries are filled by collateral vessels) consider arterial reconstruction with a bypass graft
name three procedures of surgical reconstruction
femoral–popliteal bypass, femoral– femoral crossover and aorto–bifemoral bypass grafts.
what is the purpose of amputation?
relieve intractable pain and death from sepsis and gangrene.
what is gabapentin used for?
treat the gruelling complication of phantom limb pain
what is acute limb ischaemia?
This is a surgical emergency requiring revascularisation within 4-6 hours to save the limb
what are some of the causes of acute limb ischaemia?
Acute limb ischaemia (ALI) may occur because of embolic (38%) or thrombotic disease (40%), graft/angioplasty occlusion (15%), or trauma. Emboli are sudden e,g, in those without previous vessel disease
what are the common causes of embolus?
cardiac thrombus and cardiac arrhythmias
what is an uncommon cause of embolus?
rheumatic fever
how may thrombus form?
- acute thrombus may form on a chronic atherosclerotic stenosis in a patient who has previously reported symptoms of claudication
- thrombus may also form in normal vessels in patients who are hypercoagulable because of malignancy or thrombophilia defects.
prosthetic or venous grafts may also thrombose either de novo or secondary to a developing ____ either in the ____ or int the native vessels
prosthetic or venous grafts may also thrombose either de novo or secondary to a developing stenosis either in the gradt or int the native vessels
symptoms of acute limb ischaemia- patients complain of the 6 ps, what are they?
pallor, pulseless, painful, paraesthesia, paralysis and that it feels perishingly cold
In patients with known PAD sudden deterioration of symptoms with deep duskiness of the limb may indicate acute arterial _____. Thus appearance is due to extensive _______ collaterals and must not be misdiagnosed as ___/_____
In patients with known PAD sudden deterioration of symptoms with deep duskiness of the limb may indicate acute arterial occlusion. Thus appearance is due to extensive pre-existing collaterals and must not be misdiagnosed as gout/cellulitis
what helps the pain of acute limb ischaemia?
- Helped by sitting and putting the leg in a dependent position
- helped by getting up and walking about
what sign of acute limb ischaemia suggests irreversibility?
onset of fixed mottling
management for ALI is dependent on the degree of _____. Patients showing improvement may be treatable with _____. Otherwise this is an emergency and may require urgent open surgery or ______.
is dependent on the degree of ischaemia. Patients showing improvement may be treatable with heparin. Otherwise this is an emergency and may require urgent open surgery or angioplasty.
management for ALI:
If the occlusion is embolic, the options are_____ ______ (_____ catheter) or local _____, eg tissue plasminogen activator
If the occlusion is embolic, the options are surgical embolectomy (fogarty catheter) or local thrombolysis , eg tissue plasminogen activator
when may a bypass graft be required for ALI?
after occlusion of a popliteal aneurysm or acute-on-chronic lower limb arterial disease
when an ischaemic limb is ________, the sudden improvement in blood flow can cause _______ injury with the release of _____ ______ into the circulation. In muscle compartments the consequent ______ may lead to ______ syndrome
- this requires a _______
when an ischaemic limb is revascularised, the sudden improvement in blood flow can cause reperfusion injury with the release of toxic metabolites into the circulation. In muscle compartments the consequent oedema may lead to compartment syndrome
this requires a fasciotomy
___ in 10 of IC patients will losa a leg every 5 years if they continue to smoke
1
___% of all major amputees are diabetic
45% of all major amputees are diabetic
