Chapter 5: Doppler Segmental Pressures (LE) Flashcards

1
Q

Doppler segmental pressure capabilities

A

asses presence/ severity of arterial disease

combine with doppler velocity or volume pulse waveform

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2
Q

segmental pressure results: stenosis vs occlusion

A

cannot differentiate between stenosis vs occlusion

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3
Q

segmental pressure results: ? area of obstruction

A

cannot precisely localize area of obstruction

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4
Q

segmental pressure results: CFA vs iliac disease

A

cannot distinguish between CFA or iliac disease

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5
Q

segmental pressure results: calcified vessels

A

give falsely elevated doppler pressures

ex: diabetics, end stage renal disease

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6
Q

segmental pressure results: uncompensated CHF

A

gives decreased ankle and brachial indices

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7
Q

segmental pressure results: cuffs are too small/too tight

A

elevated pressures

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8
Q

patient positioning for segmental perssures

A

pt should rest 20 minutes prior to exam
supine
legs same level as heart

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9
Q

if the cuff is too large for a limb segment

A

BP is falsely lower

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10
Q

if the cuff is too narrow for a limb segment

A

BP is falsely higher

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11
Q

technique

A

cuff placed straight on extremity, not on bony prominence
cuff bladder placed over artery
width of cuff should be about 20% greater than diameter of limb

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12
Q

the cuff bladder placement is important because

A

appropriate technique ensures the bladder inflation transmits pressure quickly into the tissue to compress the artery

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13
Q

The four cuff method (bilateral)

A
brachial
high thigh
above knee
below knee
ankle
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14
Q

the four cuff method size

A

12 x 40 cm

cuff bladders longer for thighs

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15
Q

three cuff method (bilateral)

A

brachial
one thigh cuff (19 x 40cm)
below knee
ankle

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16
Q

three cuff method size

A

thigh cuff 19 x 40cm but all else

12 x 40 cm

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17
Q

difference between 4 cuff and 3 cuff method

A

two thigh cuffs provide prx and dst pressure measurements but falsely elevate BPs
3 cuff is more accurate due to one cuff on thigh

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18
Q

optimizing doppler signal for segmental pressures

A

8-10 MHz probe
angle probe 45-60 degrees to skin
angle probe so blood flow moves antegrade (towards the probe)

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19
Q

due to vessel angulation, probe angle behind the knee may be closer to

A

90 degrees to skin

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20
Q

order of segmental pressures

A

Brachial (upper arm, brachial artery)
Ankle (PTA or DPA, peroneal only if necessary)
Calf (PTA or DPA whichever has highest pressure)
Above the knee (same as calf, can use pop artery if difficult to obtain)
High thigh

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21
Q

what is the reason you start at the ankle and move proximally

A

to eliminate possibility of underestimating the systolic pressure measurement

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22
Q

what is required of the BP cuff to make this accurate

A

complete cessation of blood flow is required
cuff inflated to 20-30mmHg beyond last audible Doppler arterial signal

OR

inflate cuff 20-30mmHg higher than the highest brachial pressure

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23
Q

if pressure measurements must be repeated:

A

the cuff should be fully deflated for about a minute prior to repeat inflation

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24
Q

systolic pressure is recorded as

A

the pressure at which the first audible doppler arterial signal returns

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25
Q

ABI (ankle/ brachail index) is calculated by

A

dividing the ankle pressure by the higher of the two brachial pressures

26
Q

another term for ABI is

A

ankle/arm pressure index (API)

27
Q

ABI > 1.0

A

Normal

28
Q

ABI >.9 - 1.0

A

may be wnl

29
Q

ABI .8-.9

A

mild arterial disease

30
Q

ABI .5 - .8

A

claudication (moderate disease)

31
Q

ABI < .5

A

rest pain (severe disease)

32
Q

in compressible vessels:

A

falsely elevated and inaccurate pressures

33
Q

At what point is an ABI considered incompressible/unreliable?

A

> 1.3 - 1.5

34
Q

some authors feel that

A

ankle pressure <50mmHg is better at predicting symptoms at rest than an ABI of .5

35
Q

Strandness work suggests

A

ABI of > or = to .5 represents single segment disease and < .5 represents multiple lesions

36
Q

Segmental pressure drops of what between levels indicates significant obstruction

A

30 mmHg

37
Q

A horizontal difference of what suggest obstructive disease

A

20-30 mmHg suggests diesaes at or above level in the leg with the lower pressure

38
Q

four cuff technique high thigh pressure

A

usually > or = to 30 mmHg than highest brachial pressure

39
Q

Four cuff technique and at knee and below knee pressures

A

should be at least the same as the highest brachial

40
Q

Three cuff technique thigh pressure

A

similar to highest brachial pressure

41
Q

Toe pressures for foot and toe ulcers that failed to heal

A

<30mmHg

42
Q

when ankle pressures cannot be relied upon (diabetics) what is more reliable

A

toe pressures

43
Q

benefits of exercise and segmental pressures

A

helps differentiate between true and pseudo-claudication

determine presences / absence of collaterals

44
Q

contraindications of exercising for this exam

A
SOB
severe hypertension
cardiac problems
stroke
walking problems
45
Q

technique for exercise during segmental pressures

A

pt walks on tredmill at <12% elevation

1.5 MPH for minutes or until symptoms increase to severity where pt must stop

46
Q

what should you document during exercise

A

duration of walking
MPH
onset
location and progression of symptoms

47
Q

post exercise dopplers obtained:

A

both ankles (abnormal first) then higher brachial

48
Q

Normal post exercise ABI

A

increases

49
Q

Abnormal post exercise ABI

A

decreases minimally or to a severe amount

50
Q

with drop after exercise pressures should be obtained

A

every two minutes until pre exercise pressures are attained

51
Q

Segmental pressure ABI interpretation includes

A

Duration of exercise
length of time to recover
pressure changes from pre to post exercise

52
Q

single level disease recovery

A

takes 2 to 6 minutes for the ABIs to increase back to resting levels after exercise

53
Q

Multi level disease recovery

A

takes 6-12 minutes for the ABIs to increase back to resting levels after exercise

54
Q

If patient cannot walk on the treadmill what technique should be used

A

reactive hyperemia

55
Q

reactive hyperemia is an

A

alternate method for stressing the peripheral circulation

56
Q

reactive hyperemia technique

A

bilat thigh cuffs (19 x 40) inflated to 20-30mmHg above brachial BP
maintain pressure for 3-5 min
ABIs are obtained upon release

57
Q

how does the reactive hyperemia technique work

A

produces ischemia and vasodilation distal to the occluding cuffs

58
Q

normal limb ABI in reactive hyperemia

A

may show drop of 17-34%

59
Q

reactive hyperemia single level disease

A

less than or equal to 50% drop in ankle pressure

60
Q

reactive hyperemia multi level disease

A

> 50% ankle pressure drop

61
Q

why is treadmill testing preferred?

A

produces physiologic stress that reprodruces patients ischemic symptoms