Chapter 11 Flashcards
what are capabilities for duplex UE?
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
what are the limitations for duplex?
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
what is patient positioning for duplex?
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)
what is duplex scanning consist of ?
combo of real time B mode imaging- gray scale
and Doppler spectral analysis
what does doppler color flow imaging?
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)
what is the ideal sample size for pulse doppler?
1-1.5mm
what transducer is used for duplex?
7 or 5 MHz
what vessels are evaluated with duplex?
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
T/F upper extremities have a higher incidence of becoming stenotic
false
more used for dialysis access grafts
what transducer do you use for a hemodialysis access graft?
7 or 5 MHz linear array
what should you evaluate with a hemodialysis access graft?
ausculatate the access for bruit and/or palpate for a thrill (vibration).
T/F a stenotic graft can also have a thrill
true
how should you evaluate dialysis access grafts?
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
what is the assessment site for dialysis access Brescia-cimino fistula?
inflow artery, anastomosis, outflow vein
which approach is used to evaluate gray scale for thombus, stenosis etc
long/ trans
what is obtained at appropriate sites and as needed?
doppler PSV and volume flow
what does documentation consists of video tape or prints?
documentation consists of video tape and prints
what percentage when you should start to observe for stenosis?
> 50% diameter reduction
what should you observe for an occulsion?
observe for lack of doppler signals (images and / or waveform) and the proverbial thump which is obtained proximal to occlusion
what is an aneurysm?
dilation of the vessel from degeneration and/or weakening of the wall
which aneuryms are associated with embolization to the digits?
subclavian aneuryms
what can ulnar artery aneuryms can form?
in response to using the palm as a hammer
what do you identify/ document with hemodialysis access?
if present location, extent, and type of any aneurysmal changes, puncture sites, peri-graft fluid, thrombus
T/F PSV and EDV vary with hemodialysis grafts
true
usually elevated
