1.5 Renal Dialysis Fistulas & Grafts Flashcards Preview

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Flashcards in 1.5 Renal Dialysis Fistulas & Grafts Deck (35)
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1
Q

What is the most common Brescia-Cimino fistula presentation?

A

Anastomosing the side of a radial artery to the end of a cephalic vein. (most common)
or
The brachial artery to cephalic or basilic vein

2
Q

Reasons for doppler Ultrasound? (9)

A
  1. Inadequate dialysis
  2. Thrombosed access
  3. Perigraft mass
  4. UE welling
  5. Decreased thrill or pulse
  6. Suspected steal
  7. Infection
  8. Bleeding
  9. Post revison follow up
3
Q

What are the methods of evaluation?

3) (one more common

A

Most common = Duplex ultrasound
Arteriography
Fistulography

4
Q

What frequency probe is preferred for duplex ultraosund

A

10-12Mhz

5
Q

Do you want high or low flow settings for the Ultrasound?

A

High

6
Q

Why do you need to decrease color gain?

A

To minimize bruit

7
Q

What position should the patient be in for duplex ultrasound

A

Supine

8
Q

What does the doppler angle need to be?

A

60 degrees

9
Q

Record PSV at the native artery prox, the ______, ___,____, _______ (4)

A

arterial anastomosis, graft, venous anastomosis, venous outflow

10
Q

With an AV fistula how many sites should be sampled distal to arterial anastomosis?

A

2-3 sites

11
Q

What is the volume flow rate formula?

A

Volume flow rate (q) ml/min = TAV (Time average velocity) x area (cross sectional area of the vessel) x 60 (60 seconds)
Q= TAV x area x 60

12
Q

To rule out steal from native circulation with duplex what do you look for?

A

Retrograde flow in the inflow artery distal to the anastomosis

13
Q

Which vessel is there a high occurrence of thrombus in dialysis graft patients?

A

Subclavian vein

14
Q

Which exam is used to rule out central vein thrombosis?

A

UE DVT scan

15
Q

What does a normal Arterial limb waveform look like?

A

1) High velocity
2) continuous forward flow through diastole
3) Marked spectral broadening

16
Q

What does a normal venous limb waveform look like?

A

1) slightly lower velocity than arterial

2) most common site of stenosis/ thrombosis

17
Q

What is the Normal PSV for grafts/AV fistulas

A

PSV= 100-400 cm/s

18
Q

What is the Normal EDV for grafts/AV fistulas

A

EDV= 60- 200 cm/s

19
Q

Normal grafts and AV fistulas have ____ flow and ____ resistance

A

high;low

20
Q

will color flow be seen in an graft with an occlusion?

A

No

21
Q

With an occlusion There will be no flow in vein_______ to the fistula

A

distal

22
Q

_________ resistance flow will be seen in the artery leading to the graft or fistula

A

High

23
Q

____ venous outflow with an occlusion from a graft or fistula

A

low

24
Q

> 50% stenosis in GRAFT & FISTULA has a PSV of greater than..

A

> 400 cm/s

25
Q

> 50% stenosis in GRAFT & FiSTULA has a velocity ratio of greater than…

A

> /= 2:1

26
Q

> 75% stenosis in GRAFT& FISTULA has a velocity ratio of greater than…

A

> /= 3:1

27
Q

Velocity values may be unreliable due to variations in vein _________ and limited when estimating doppler angle in __________fistuala’s anastomosis

A

diameter; tortuous

28
Q

Graft Flow volume with poor dialysis, pending graft failure

A

<300 ml/min

29
Q

Graft Flow volume < 500ml/min means?

A

Increased risk of graft failure

30
Q

Graft Flow volume & AV FISTULA normal range?

A

> 800 ml/min

31
Q

Graft Flow volume with possible congestive heart failure?

A

> 1500 ml/min

32
Q

AV fistula adequate dialysis has a flow volume of greater than _____ with _____mm outflow vein

A

500; 4

33
Q

What is the most common abnormality in renal dialysis, fistulas and grafts

A

Venous anastomosis stenosis (50-90%)

34
Q

Other abnormalities include in renal dialysis, fistulas and grafts(8)

A
  1. Venous outflow obstruction
  2. Pseudoanerysm
  3. Diffuse aneurismal dilation
  4. hematoma
  5. perigraft abcess
  6. Hematoma
  7. Intimal flaps (from needle punctures)
  8. Arterial anatomic stenosis (15%)
35
Q

Ultrasound maybe used to identify/monitor grafts and lesions as well as (3)

A
  1. baseline exam for F/U studies
  2. Assess maturity of an AV fistula/graft
  3. Identify grafts in jeopardy of failure