Arterial Testing, Doppler Analysis, & Segmental Pressures

Question 1

plethysmography

Answer 1

measurement of blood volume changes

Question 2

what are the two types of plethysmography

Answer 2

volume plethysmography (PVR) and photoplethysmography (PPG)

Question 3

volume plethysmography (PVR)

Answer 3

reflects the amount of blood moving under a cuff

Question 4

photoplethysmography (PPG)

Answer 4

assessment of cutaneous blood flow

Question 5

what is pulsatility index (PI) and what is considered normal/abnormal?

Answer 5

peak to peak frequency difference divided by the mean (average) frequency

normal >4.0
abnormal <4.0 - consistent with a >60% stenosis proximal to the sample

Question 6

describe acceleration time (AT) and what is considered normal/abnormal?

Answer 6

proximal obstruction results in a delayed time interval between the onset of systole and peak velocity.

normal AT <133 milliseconds
abnormal AT >133 milliseconds = proximal obstruction

Question 7

what is the 20% rule when it comes to the four cuff method

Answer 7

width of cuff 20% greater than the diameter of the limb, using a too small cuff results in artifactually high pressure

thigh pressure will be = 30mm/hg higher

Question 8

what disease can result in partially compressible or incompressible vessels and result in FALSELY ELEVATED PRESSURES

Answer 8

calcified vessels (medial calcinosis)

Question 9

pressure measured represents

Answer 9

the pressure UNDER the cuff

Question 10

what is the ABI formula

Answer 10

highest ankle pressure divided by the highest brachial pressure

Question 11

interpretate ABI >1.0

Answer 11

normal

Question 12

interpretate ABI >0.9-<1.0

Answer 12

probably abnormal*, exercise patient if borderline

*varies in the literature 0.9-0.96 being normal

Question 13

interpretate ABI <0.8

Answer 13

probable claudication (single level disease)

Question 14

interpretate ABI <0.5

Answer 14

multi-level disease or long segment occlusion

Question 15

interpretate ABI <0.3

Answer 15

ischemic rest pain

Question 16

when is ABI considered abnormal in lower extremity

Answer 16

20-30mmHg or greater pressure gradient (drop) side to side or from one level to the next is significant in the Prescence of abnormal ABI

Question 17

when is toe pressure considered very poor healing potential

Answer 17

30 mmHg or less

Question 18

when is ABI considered abnormal in upper extremity

Answer 18

15-20mmHg or greater pressure gradient (drop) side to side or from one level to the next is significant

a difference of >20mmHg between the radial and ulnar suggests obstruction in the vessel with the lower pressure