Arterial (Quiz 2) Flashcards
What is PAOD (peripheral arterial occlusive disease)?
atherosclerosis of the extremities (virtually always lower) causing ischemia
Is indirect testing subjective or objective?
subjective - works with numbers (quantification)
What are the symptoms of PAOD?
intermittent claudication, rest pain
advanced - thickening of toe hair, skin discoloration/scaliness, evaluation pallor/dependent rubor, ulceration/gangrene, blue toes (may indicate aneurysmal disease)
What is intermittent claudication?
pain in large muscle groups caused by activity
pain must be dscribed as fatigue, cramping, aching, or tiredness
Where does intermittent claudication usually take place?
calf, thigh, or butticks
List the true claudication symptoms.
relieved with quiet standing, easily reproducible with same amount of activity
(site of symptoms occurs distal to site of disease)
What are diseases that may mimic claudication?
spinal stenosis, herniated disk, osteoarthritis
If pain is variable, is it intermittent claudication?
no
With intermittent claudication, describe why there is leg pain with activity.
if blockage is in leg arteries, it compensates and dilates distal to the blockage-
once walking, compensation will not be enough; once the threshold is reached, pain starts
Why is there rest pain with claudication?
due to gravity not helping push blood through vessels
What is the overall purpose of the vascular laboratory in patients with lower extremity PAD?
In other words, what will the results of the test tell you?
severity, location, and the hemodynamic significance
List historical symptoms (from taking patient history) consistent with peripheral disease.
coexisting conditions such as stroke, transient ischemic attack (TIA), coronary artery disease (CAD), hypertension, diabetes, lipid disorders, smoking history, family cardiac/peripheral vascular history
the more of these symptoms, the more likely they are to have the disease
How should the patient be positioned when doing a peripheral test?
leg externally located, patient flat as possible, supine
What are the components of physiologic testing?
Doppler pulses, segmental pressures, plethysmographic waveforms, digital PPG waveform and pressure
What position should you be in if you want the best Doppler signal?
45 degree angle to flow
List the order of branching lower extremity arteries.
CFA bifurcates into the profunda and superficial femoral artery, superficial FA becomes the popliteal artery and then becomes the tibial-peroneal trunk and bifurcates into the posterior tibial and peroneal arteries
the ATA arises from the popliteal artery; dorsalis pedis branches off the ATA.
What does a normal doppler waveform look like?
bidirectional and bi to triphasic
flow reversal relates to greater resistance of flow
PAOD reduces flow energy distal to the lesion; what does this look like?
reduction of peripheral resistance, reduced amount of fow reversal
In critical stages of PAOD, what happens?
arteriolar bed can no longer dilate to increase blood flow and the patient experiences rest pain
If there is disease, what will happen to the pressures in the leg?
there will be a significant pressure drop
What is a TBI?
when toe pressure is compared to the brachial pressure
What is an ABI?
ankle pressure compared to brachial pressure
percentage of pressure you have compared to right atrium of heart
ex: if heart pressure is 100 and thigh is 60l it has 60% of prssure (ABI=0.6)
If waveforms and pressures appear unhealthy to begin with, what is the conclusion?
stenosis is proximal to the CFA
Before beginning a segmental systolic pressure exam, what should be done?
let patient rest for 10-15 minutes (which ensures true resting levels of blood flow)
How do you find the right BP cuff fit?
the width should be 20% wider than the diameter of the underlying limb
What happens if the BP cuff is too narrow or too wide?
if too narrow, falsely elevated pressure
if too wide, falsely lower pressure
What are the two ways segmental systolic pressures can be taken?
three cuff method and four cuff method
What is the three cuff method?
one large cuff on thigh, one below the knee, one at the ankle
What is the four cuff method?
two smaller cuffs on thigh(hihg and above knee), one at calf, and one at ankle
Is one cuff method better than the other?
four cuff method allows ability to further define level of disease by seperating iliofemoral disease from superficial femoral artery disease
At what levels are pressures obtained from?
pressure are obtained from the ankle level followed by the calf then thigh levels
What is used for pressure measurement up the limb?
the PTA or DPA (which ever is highest)
Doppler signal is obtained ___ to cuff.
distal
The cuff should be inflated ____mmHg above point where signal disappears.
20 mmHg
What is the rate of deflation of the cuff?
3 mmHg/s
What indicates the overall severity of PAOD?
ABI
How is ABI calculated?
calculated by dividing highest systolic ankle pressure by the higher of the two brachial systolic pressures
With an ABI of greater than 1.3, what is the level of severity of PAOD?
incompressible
What is a normal ABI?
0.9 - 1.3
about 1
What indicated mild PAOD?
ABI of 0.75-0.89
What indicates moderate PAOD?
0.5-0.75
What indicates severe PAOD?
less than 0.5
What indicates tissue threatening severity of PAOD?
less than 0.35
What is considered a significant change in ABI between studies?
change of 0.15
What do excessively high ABI values typically correspond to?
calcified arteries
interpretation then relies on waveform analysis
What disease may you see calcified vessels in?
diabetes
What does ABI indicate?
overall severity of disease, but not necessarily the site
What happens to systolic pressures as you travel distally down the leg?
pressures increase
Pressure drops of ___ indicate presence of proximal obstruction.
greater than 30 mmHg
Width of thigh cuff changes interpretation. What does a single large cuff do? a narrow cuff?
single large cuff results in a thigh pressure equal to the brachial pressure
us of a narrower high thigh cuff results in higher thigh pressure(about 30mmHg above brachial)
What should doppler waveforms proximal to the knee look like?
triphasic/biphasic and bidirectional
Why is exercise testing done?
primarily used in patients with intermittent claudication with normal ABIs at rest