Hemodialysis access grafts

Pregunta	Respuesta
Method of removing toxic substances from blood when the kidneys are unable	Dialysis
What is a life saving technique for pts with acute and chronic kidney failure?	Dialysis
This circulates blood through special filters to remove toxins.	Hemodialysis
What is necessary for a successful hemodialysis?	Access to the vascular system
A AV fistula must support velocities as high as _____ thus a peripheral IV will not work!	250 ml/min
What are the graft flow volumes?	<250- poor, 300-1000 normal, >1400- too high!
What is the flow volume equation?	Q=area x mass vel. X 60 sec
This involves the surgical joining of an artery and vein under the skin	AV fistula
Once the fistula is in place, what will happen to it?	The vein will stretch due to high velocities
Why are native veins not used in dialysis?	They are not suitable for AV fistulas so a graft is implanted
What are two things they could use as donor veins while creating a fistula?	Own sap heinous vein, bovine carotid artery, synthetic graft
What are 3 types of grafts and fistula?	Fistula, access grafts, common loop
Aka Brescia cimino fistula	Fistula
What arm are fistula generally put in?	Non dominate arm
What are the types of fistulas?	Radial artery to cephalic vein, ulnar artery to basilic vein
What is the most common type of fistula?	Radial artery to cephalic vein
What is the benefit of a fistula?	Long term latency and low complication rate
What are the types of access grafts?	Common straight, common loop
What are 3 types of access grafts?	Synthetic, gortex, or donor
This is when a vessel connects straight from artery to vein.	Common straight
What are some examples of a common straight?	Distal radial artery to cephalic, distal radial to median cubital, distal radial to basilic, distal brachial artery to proximal basilicoaxillary vein
What are some examples of a common loop graft?	Distal brachial artery to cephalic vein, distal brachial artery to median cubital vein, distal brachial artery to basilic vein, proximal brachial artery to ancillary vein, superficial femoral artery to greater saphenous
What do pts with a long term dialysis graft have to do?	Have multiple grafts put in due to the short patency of grafts
What are the complications of a graft, and or the indicators to asses the graft?	Thrombosis, stenosis, infection, arterial steal, distal venous hypertension, aneurysms/ pseudoaneurysms
Another word for occlusion	Thrombosis
Where do stenosis generally occur in a fistula or graft?	Prox/ distal anastomoses, center
Digits/ hand ischemia	Arterial steal
Are aneurysms and pseudo aneurysms common in grafts and fistulas?	Yes
What type of transducer do you use for a hemodialysis graft?	7.5-10 MHz
Do you ever take a BP over dialysis graft?	No
This will have a palpable thrill due to high velocities?	Hemodialysis graft
What is the evaluation protocol for hemodialysis grafts?	Document with 2d and Doppler the native inflow artery, arterial anastomoses, body of grafts (prox, mid, distal), venous anastomoses, native outflow vein
What are you looking for during you evaluation of the hemodialysis graft?	Aneurysms, leaks, peri graft fluid collections, stenosis, occlusions
Arterial inflow proximal to the graft/ fistful as should demonstrate low resistant waveforms.	Native artery doppler
Arterial flow should remain low resistant but velocities may be increasing and spectral broadening may be noted.	Proximal arterial graft anastomoses Doppler
What do you obtain in Doppler when looking at the graft?	Obtain systolic velocities prox, mid, distal
What should flow in the graft look like in Doppler?	Mixture of arterial and venous characteristics with turbulence and spectral broadening
Are stenosis in the distal anastomoses common?	Yes
Once you have obtained the distal portion of the graft, what do you move on to next?	Distal graft venous anastomoses
The native vein which has become arterialized is often referred to as ?	Efferent and afferent
What do you evaluate for in the native venous outflow/ efferent vein?	Doppler distal to the anastomoses, demonstrate compressibility, evaluate for thrombus, obtain velocities in native cephalad to the graft in upper arm, flow should return to normal here
A stenosis in the native venous outflow/ efferent vein is commonly caused by?	Neo intimal hyperplasia
What are you assessing the peri graft/ fistula tissue for?	Hematoma, aneurysm, pseudo aneurysm
This is a occurrence where the fistula graft will steal blood from the hand	Arterial steal
How do you assess for a arterial steal?	Obtain digit pressures, compare both to as symptomatic hand
What does a absent thrill indicate?	Occlusion
What will a stenosis in a fistulas/ graft look like?	Region of extremely high velocities
Do grafts and fistulas have a high failure rate?	Yes
What are the guidelines for a normal graft/ fistula?	High systolic velocities- 100-400 cm/s, high diastolic velocities- 60-200 cm/s
What will the flow pattern of a normal graft/ fistula look like?	Disorganized with spectral broadening
What are some indications of an occlusion?	No flow in graft with color or Doppler, no flow in efferent vein distal to fistula, high resistance in artery leading into fistula, low/ diminished venous outflow
What is the criteria for dialysis graft stenosis?	Mild- velocity increase <50% of preceding segment, moderate- velocity increases between 50-90% of preceding segment! severe- velocity increases > 100% of preceding segments

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	Creado por ecmarchese hace casi 11 años