Chapter 11

Question 1

what are capabilities for duplex UE?

Answer 1

localize stenosis/ occlusion; evaluate degree of stenosis
determine the presence/absence of aneurysm
post op study: hemodialysis access or arterial bypass graft
detect AVFs or other unusual abnormality

Question 2

what are the limitations for duplex?

Answer 2

limited access to extremity.. dressings, skin staples, sutures
pertaining to hemodialysis access grafts
-graft angulation
-difficult to adequately evaluate the outflow vein in an obese patient

Question 3

what is patient positioning for duplex?

Answer 3

patient is supine with small pillow under head
extremity close to the examiner
arm is at a 45 degree angle from the body externally rotated (pledge position)

Question 4

what is duplex scanning consist of ?

Answer 4

combo of real time B mode imaging- gray scale

and Doppler spectral analysis

Question 5

what does doppler color flow imaging?

Answer 5

doppler info is displayed on image after evaluated for phase (direction toward or away from transducer) and its freq content (hue or shade of the color)

Question 6

what is the ideal sample size for pulse doppler?

Answer 6

1-1.5mm

Question 7

what transducer is used for duplex?

Answer 7

7 or 5 MHz

Question 8

what vessels are evaluated with duplex?

Answer 8

neck vessels identified with attention given to innominate artery on the R and LCCA branches of the arch

• subclav
• axillary
• brachial
• radial
• ulnar
• palmar arch

Question 9

T/F upper extremities have a higher incidence of becoming stenotic

Answer 9

false

more used for dialysis access grafts

Question 10

what transducer do you use for a hemodialysis access graft?

Answer 10

7 or 5 MHz linear array

Question 11

what should you evaluate with a hemodialysis access graft?

Answer 11

ausculatate the access for bruit and/or palpate for a thrill (vibration).

Question 12

T/F a stenotic graft can also have a thrill

Answer 12

true

Question 13

how should you evaluate dialysis access grafts?

Answer 13

inflow artery
arterial anastomosis
continue through the body of the graft
observe for aneurysm, puncture sites, peri-graft fluid
use color to observe for flow changes, turbulence, flow channel changes
venous anastomosis
outflow vein

Question 14

what is the assessment site for dialysis access Brescia-cimino fistula?

Answer 14

inflow artery, anastomosis, outflow vein

Question 15

which approach is used to evaluate gray scale for thombus, stenosis etc

Answer 15

long/ trans

Question 16

what is obtained at appropriate sites and as needed?

Answer 16

doppler PSV and volume flow

Question 17

what does documentation consists of video tape or prints?

Answer 17

documentation consists of video tape and prints

Question 18

what percentage when you should start to observe for stenosis?

Answer 18

> 50% diameter reduction

Question 19

what should you observe for an occulsion?

Answer 19

observe for lack of doppler signals (images and / or waveform) and the proverbial thump which is obtained proximal to occlusion

Question 20

what is an aneurysm?

Answer 20

dilation of the vessel from degeneration and/or weakening of the wall

Question 21

which aneuryms are associated with embolization to the digits?

Answer 21

subclavian aneuryms

Question 22

what can ulnar artery aneuryms can form?

Answer 22

in response to using the palm as a hammer

Question 23

what do you identify/ document with hemodialysis access?

Answer 23

if present location, extent, and type of any aneurysmal changes, puncture sites, peri-graft fluid, thrombus

Question 24

T/F PSV and EDV vary with hemodialysis grafts

Answer 24

true

usually elevated

Question 25

what can low PSV obtained in access graft indicate?

Answer 25

arterial inflow problems

Question 26

where are the most common sites for stenosis in a graft?

Answer 26

venous anastomosis and outflow vein

Question 27

why is the most common site for stenosis formed?

Answer 27

by increased arterial pressure introduced to a vein/ intimal hyperplasia

Question 28

what are other hemodynamic complications?

Answer 28

large blood volume shunted from artery to lower resistant venous circulation, can increase venous return resulting in CHF
a steal syndrome

Question 29

what is a steal syndrome?

Answer 29

the distal arterial blood flow is reversed into the lower resistant venous circulation and can cause pain on exertion, pallor and coolness of the skin distal to the shunt (in hand)

Question 30

what is the formula for volume flow?

Answer 30

VF= ml/min (graft)