AVF

Specialties Urology

Published

Hello, wondering if anyone can help me with this question..... I have a few pt's that I've assessed the accesses on (AVF's) and all I can hear/feel is a pulse at the anastomosis, and it diminishes as I get to the venous. They are pulsatile, and I don't feel the thrill (or "purr"), nor the machinery, continuous-bruit at the anastomosis, only a strong pulse. I'm an LPN at my office and when I report this to my CN, she listens briefly and says "It's Okay".

One of my pt's in particular had this for 2 mos, and she kept saying "It's okay". I had more and more trouble cannulating her venous, and then her arterial pressures ran -250 and -280. The other CN finally sched. her with her Vasc. Surg. He ended up placing an AVG, and a CVC until the graft healed. Then when her CVC developed drainage (over 2wks of hearing "It's Okay" again), The pt. ended up in the hosp for infection... That upset me, I had to vent about that, sorry.

Anyways, I would like to know if this "pulse" is normal. Everything I read says you should always feel the thrill, hear a bruit, and feel a pulse on an AVF. My CN says "If you just feel the pulse, it's okay to cannulate." (She says this also applies to NEW AVF's).

I'm the only one in my office that actually listens to all the accesses. I'm a nurse, and I am thorough at what I do, so I might be irritating her when I report possible abnormalities to her.

I have tried looking online for abnormal AVF sounds, but all I get are "Whistles, Bruits", not abnormal pulses. :/ Can someone give me some advice???

Apologies for the long message... :)

Thanks to All...

Specializes in Dialysis.

You are correct, a thrill and bruit should be present although if the BP is low it may be difficult to assess. The gold standard would be an ultrasound that would determine the minimum flow neccessary for dialysis (600ml a minute), the size of the access (minimum 6 mm diameter), and the depth of the fistula (minimum 6mm from the surface). This would indicate a mature fistula. Not all nephrologists will order this and will many times let you be the judge if you can canulate and run a patient successfully. But if the flow is a least 600ml a minute there should be some turbulence in that fistula that you can palpate and hear.

Specializes in Dialysis.

My post should read maximum 6mm from the surface. Some fistulas require a second surgery to bring them up to this depth. Any deeper and the needles will be sticking straight up.

My initial training even before dialysis was to feel the thrill and listen with a stethoscope for the bruit. Now, for dialysis our policy is that a patient needs both a thrill and a bruit. I tried to look up some valid sources of information for you. Sounds like your facility needs a better policy on how to assess AV fistula and what to do if neither a thrill and/or a bruit are present.

Fistula First for Dialysis Facilities - Renal Network 11

http://www.annanurse.org/download/reference/practice/hemodialysisFactSheet.pdf

http://www.annanurse.org/download/reference/practice/vascularAccessFactSheet.pdf

This is why monthly ABF's are such a great frontline indicator of failing accesses. It provides a real time tracking of blood flow over time.

Don't get me wrong. Subjective findings (such as thrill/bruit/pressures) are valuable, but are less reliable when attempting to more accurately quantify/qualify actual access performance.

Do you guys not do Access Flow testing? We do ours monthly and it basically tells us the blood flow through the fistula or graft. You can then see monthly trends if the flow is getting slower. If it's coupled with increasing arterial / venous pressures, difficulty with cannulation, or attaining prescribed blood flow then you know it's certainly time for them to see their vasc. surgeon. I can't begin to tell you how many AVF/AVG's have their life prolonged by doing access flow testing.

Specializes in Dialysis.

You're right, that was an access getting ready to clot. You were right to be concerned. If your Charge nurse blows you off, go higher. Manager, FA. You are the patient's advocate. The nephrologist doesn't round weekly? Alert them as well when you have concerns.

Once you've heard that "whistling" of a failing access you'll never forget it. Access Flow monitoring should be mandatory for all AVF/AVG patients.

We do access flows in all our PTs. Can someone tell me about the >2000 reading. Some say oh that's great but some say no. I can't get a direct answer

Specializes in Dialysis.

ooh Love, that's a great question. I'd love to hear the answer for that as well. We interpret that as "great" since it is above the established 600-600 goal. Want to know what others say.

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