ARTERIAL - SEGMENTAL PRESSURES AND PLETHYSMOGRAPHY

analog doppler

graphical recording of pulsatile doppler signal in a nonspectral or strip chart recording

analog doppler displays _____ as a single line, not _____

average shift, a range of frequency shifts

t/f: analog doppler displays turbulence/spectral broadening

false

analog doppler uses a ______ MHz ______-style transducer

8-10, pencil

limitations of lower extremity CW doppler exam

• bandages, casts, wounds

• room temp affects resistance

• CANNOT properly localize an area of obstruction

• underestimates high velocities and overestimates low velocities

in an le segmental pressure exam, the probe should be at an angle of _____ with the skin

45 degrees

le segmental pressure exam - pressures are obtained from _____ to _____

ankle, thigh

cuff width should be _____% wider than the diameter of the part being measured

20

if the cuff is too wide, the segmental pressure is ______

underestimated

if the cuff is too narrow, the segmental pressure is ______

overestimated

what cuff is used for the brachial, ankle, calf

10-12 cm

what cuff is used for thigh and patients with a larger body habitus

12 cm or larger

what size cuff is used for the digits

2.5 cm

what size cuff is used for the wrists

7 cm

the _____ cuff method is most common

4

the _____ cuff method provides a more accurate mid thigh pressure

3

the 3 cuff method cannot differentiate _____ disease from _____ disease

distal femoral, popliteal

<_____mmHg between adjacent levels on the same leg is normal

30

<_____mmHg difference between same level of both legs is normal

20

rest pain is seen in patients with an ankle pressure of <_____ mmHg

50

>_____ reduction in ABI on serial exams indicates disease progression

.15

an abi of over _____ indicates noncompressibility

1.3

ankle pressures over _____ indicates noncompressibility

200

ankle pressures _____% higher than brachial indicates noncompressibility

30

an abi over over 1.0 is considered

normal

an abi of .9-1.0 is considered

asymptomatic/minimal disease

an abi of .5-.9 is considered

claudication/mild to moderate disease

an abi under .5 is considered

rest pain/severe disease

strandness criteria: an abi of over .5 means

single vessel disease

strandness criteria: an abi of under .5 means

multiple vessel disease

ankle pressures under _____mmHg are associated with non-healing wounds

80

when calculating abi, the _____ of the two brachial pressures should be used

higher

when calculating abi, the _____ of the pta or dpa pressures should be used

higher

toe pressures under _____mmHg are associated w non-healing wounds

30

a normal finger/brachial index is above

.8

normal toe/brachial index is

.6-.8

a toe/brachial index indicating claudication is

.2-.5

a toe/brachial index under _____ indicates rest pain

.2

treadmill exercise testing helps differentiate

true claudication from pseudoclaudication

exercise induces peripheral vaso_____ and can be used to evaluate autoregulation

dilation

diminished pulsatility in flow pattern is _____ after exercise

normal

how does the treadmill test work

take pre measurements then post exercise, take measurements every 2 minutes until pre exercise baseline pressures have been returned to

exercise results (normal)

pressures decrease to normal in 5 min

exercise results (single-level obstruction)

pressures and abi drop, increase to normal baseline 2-6 min post exercise

exercise results (multi-level obstruction)

pressures and abi drop, increase to normal baseline 6-12 min post exercise

after exercise, if the patient has pseudoclaudication, what will the results look like

increased or no change in the abi

reactive hyperemia

transient increase in blood flow that occurs after a brief period of ischemia

when is reactive hyperemia testing needed

• patients w poor cardiac output

• history of angina

• difficulty walking or breathing

• amputation of leg

how is reactive hyperemia testing done

1. elevate legs to 45 degrees to drain venous blood

2. inflate thigh cuff to 30-50 mmHg above brachial pressure

3. lower legs back onto table and maintain pressure in thigh cuff for up to 5 min

4. pressures are obtained upon releasing the cuff

5. obtain pressures every 30 seconds until pressures return to baseline

reactive hyperemia (normal) results

• ankle pressure drops under 35%, returns to baseline in a minute

• velocity of flow increases over 100% from resting velocity when cuff released

reactive hyperemia (single level disease) results

ankle pressure drops 35-50%

reactive hyperemia (multi level disease) results

ankle pressure drops over 50%

pulse volume recording is also known as

arterial plethysmography or volume plethysmography

how is a pvr obtained

1. patient lies supine w a wedge under their ankles to prevent cuff compression

2. 12 cm cuffs placed on thighs, calves, ankles, 7 cm on foot. for the upper extremity, 12 cm cuff is placed on the upper arm, 10 cm on forearm, 7 cm cuff wrist. inflated to 50-60 mmHg, held constant

3. pvr tracings are performed thigh to ankle on both legs at the same time

4. volume changes under the cuffs are recorded by the machine

in pvr, increased peripheral resistance will lead to _____ amplitude

increased

calf pvr tracings will have a _____ amplitude than thigh pvr tracings

higher

photoplethysmography

infrared light is released into tissues, red blood cells reflect light to photocells where it is measured, detecting cutaneous blood flow/volume changes

t/f: ppg recordings are not affected by calcified vessels

true