Peripheral Artery Disease Flashcards
ABI (ankle brachial index) equation
SBP of doralis pedis or posterior tibial artery / SBP of brachial artery
normal ABI
0.91-1.3
ABI >1.3
suggestive of calcified or uncompressible vessels seen in DM2 or CKD, needs additional vascular studies
ABI <0.9
diagnostic of PAD
If ABI are non diagnostic what study do you order?
toe-brachial index, pulse volume recordings, arterial duplex ultrasound
or get exercise ABIs
what is neurogenic claudication?
lumbar spinal stenosis Causes bilateral or asymmetrical lower extremity pain weakness or sensory loss that is exacerbated by walking or prolonged standing in erect postures,
What makes neurogenic claudication better?
sitting or assuming a stooped or flexed posture
Presentation of neurogenic claudication
bilateral or asymmetrical lower extremity pain weakness or sensory loss that is exacerbated by walking or prolonged standing in erect postures,
What is venous claudication?
lower extremity discomfort in pts with chronic venous dx. Symptoms are worse in prolonged dependent position.
modifying risk factors include:
stopping smoking graded exercise therapy to improve symptoms and decrease progression of dx
initial therapy for PAD
antiplatelet with aspirin (due to cost and efficacy). Clopidogrel can be used in pts who cannot tolerate aspirin. PTs who are symptomatic on antiplatelet need second line agents like cilostazol or a phospohdiesterase inhibitor and vasodilator that inhibits platelet aggregation and increases maximal and pain free walking distances.
cilostazol
second line drug, use after antiplatelet. DIrect arterial vasodilator and inhibitor of platelet aggregation. improves pain free walking distance and symptoms, mainly for patients who don’t meet criteria for revascularization
when is cilostazol contraindicated?
in pts with heart failure
pentoxifylline
this improves symptoms of claudication increases red blood cell deformity and improves circulation has limited benefit and is second line therapy for symptom relief. trials on efficacy are inconsistent about improving walking capacity
what is criteria for revascularization?
ABI >0.5 or failed medical or exercise therapy or unable to do ADLs. otherwise if not there yet, use cilostazol
when do we revascularize someone - surgically or percutaneously?
if someone who fails all exercise and medical therapy, who have significant disabling claudication preventing ADLs or limb threatening ischemia ABI usually 0.5
Algorithm for PAD
Clinical features of PAD
See below
Leriche’s syndrome is
triad of claudication, diminished femoral pulses, and ED
This resutls in severe aortoiliac occlusive PAD
localized hip or buttock pain, diminished femoral pulses and claudication. Hear bruits over the femoral or iliac arteries and cool extremities and prolonged venous fillign time and skin and muscle atrophy and prolonged wound healing and foot pallor
severe aortoiliac dx with PAD.
in those pts who have symptoms of intermitten claudication, erectile dysfunction, toe ulceration and NORMAL ABI what do you do?
get exercise testing then repeat ABI as this will help provoke dx
if normal ABI after exercise this excludes occlusive PAD.
ABI that decreases by >20% following exercise is diagnostic of occlusive PAD.
Risk factors for PAD?
male gender
known CAD
advancing age
DM2
HTN
HLD
black race
hyperhomocysteinemia
physical exam of PAD?
diminished pulses, decreased hair, skin pallor, arterial ulcers
Lab testing is normal
ABI <0.9 is diagnostic
ABI can be normal but if still suspect PAD get exercise ABIs
are CT angiography, MR angiography and duplex imaging helpful for PAD diagnosis?
no it’s meant for surgical planning after diagnosis is established and needs revascularization.
