Hemodialysis Access Evaluation Flashcards
(24 cards)
dialysis is treatment for ___
renal failure
dialysis requires ___
high blood flow volumes
dialysis is accomplished by the creation of ___
AVF dialysis access
dialysis
typical fistula is cannulated ___ times per week
3 times per week
synthetic grafts are typically made out of ___ and are either ____
PTFE (Gortex)
straight or looped
native autogenous fistula
vein is connected ___
directly to the artery
vein will “mature” and dilates in response to arterial pressure
____ is obtained over several cardiac cycles to calculate volume flow
time averaged mean velocity (TAMV)
AVF most common sites of stenosis
venous anastomosis
outflow vein
*hyperemic response to high flow rate/increased shear stress, trauma
___ is normal in dialysis access
bruit or thrill
native fistula anastomosis diameter is ___
4-5mm
PSV and EDV vary depending upon the type of access
typically both are ___
elevated
low PSV with low resistance waveform may indicate ___
inflow artery stenosis
volume flow varies
best used to follow access over time
normal -
abnormal -
normal > 800ml/min
abnormal < 500ml/min
general velocity criteria for >50% stenosis
at the anastomosis
PSV
velocity ratio
___ defect
PSV ≥ 400 cm/sec
velocity ratio > 3
intraluminal defect
general velocity criteria for >50% stenosis
along the venous outflow
PSV
velocity ratio
velocities less than ___
PSV ≥ 300cm/sec
velocity ratio > 2
velocities < 50cm/sec
velocity identifies ___ and does not relate to ___
identifies a stenosis
does not relate to performance of access
volume flow indicates ___ and suggests but does not identify ___
indicates performance of access
suggests but does not identify a stenosis
fistula occlusion is often evident, frequently the ___ will remain patent
artery
extravascular masses appear as
anechoic masses with no flow
extravascular masses may be ___ or ___ that has thrombosed outside the vessel
fluid collections
extravascular blood
access aneurysm
vein subjected to ___
document ___ and ___
___ is possible
vein subjected to high pressure
document size and precise location
rupture is possible
large blood volume moving through the fistula does not perfuse the body and therefore may impact ___
cardiac function (CHF)
steal syndrome
arterial blood flow ___ to the fistula is reversed flowing into the venous circulation
distal to the fistula
assessment of steal syndrome
- document ___ flow in artery distal to fistula
- obtain ___ tracing on multiple digits
- manually compress the ___
- document retrograde flow in artery distal to fistula
- obtain PPG tracing on multiple digits
- manually compress the fistula
no change - no steal
flow improves - steal
