Dialysis Graft Site Palpation

[exodus]

Everytime before I take a BP, I always palpate the radial site and the brachial sites to check to see if they pt has previously had a graft. I have a few questions about these. Why do they feel different when you palpate them, like the pulse feeling? It feels like it's pushing air through the vein, as well as the blood, like it vibrates a little bit. I don't know how to describe it, it is something you have to feel to know. But why does it feel like that. And why can't we take bp's on that arm? I've been told we're not supposed to, but what is the real reason?

The reason I check every time now is because I asked a pt if they have ever had dialysis before and they said no, so I put the BP cuff on him, and then got my ears on, and held the bell at the site, and the sound caught me off guard since for a second I was like uhm, are these breath sounds?! I was trying to figure out why it felt like that, then I realized that pt lied to me (obviously not on purpose) and they have had dialysis and there is a graft there. So I've learned with things like that, don't trust the pt. Always check and feel for yourself.

I taught my partner this today even though she's been doing these IFT's for 8+ months. She was like, hmm. Lemme ask the nurse if he has a graft somewhere, and I said, oh just check his pulse, and she went all ...what... Then I told her it feels different and you can usually tell that way.

BACK TO MY QUESTIONS! Why do they feel different? And why can't we do BP's on them?

 

[Aidey]

I used to work as a Dialysis Tech so I have the answers to your questions.

There are 2 different types of dialysis sites pertinent to your questions, fistulas and grafts. Fistulas are where the patients natural vessels are sewn together, grafts are artificial. The grafts are either taken from a bovine source, or they are plastic. They are a tube that links a vein and an artery. They feel different because they aren't normal vessel material, plus the pressure in them is much higher than in veins.

Fistulas are usually very noticeable, as they become quite large and protrude on most people. Grafts are less noticeable because the material used doesn't expand like a human vessel does. Surgical scars are left from the creation of either access site, and you can often see the needle scars from the patient repeatedly being stuck (dialysis needles are usually 15g).

The sound you are hearing is probably bruit (pronounced brew-ee), which is turbulence in the blood flow as it goes through the site.

It is strongly strongly advised that you do not do a blood pressure on an arm with a fistula or graft that is currently being used. The counter pressure of the blood pressure cuff can cause problems in the access, especially if it is a newer access.

Accesses do fail, and become clotted off. Once this happens it is generally accepted that it's safe to do a blood pressure on that arm. Some patients have up to 4 failed accesses (2 in each arm), so you really have no choice in those cases. Or they have 2 failed accesses in one arm, and a viable access in the other arm.

There are 4 main sites for accesses being places, the forearms, and the bicep. They can be placed in the upper thigh in unique situations.

Hopefully that answers your questions, let me know if you have more.

 

[Mountain Res-Q]

Nice information Aidey.

Once quesion, from a dialysis tech standpoint, would it be prefered to just take a BP off a leg when both arms are pretty used up... I know that I have had to do that from time to time in IFT some patients at the biding of the nurses...

 

[Aidey]

In the clinic, we both took them on the ankle, and we took them over "dead" access sites. It depended on what the person wanted and the status of their accesses. For some people the old accesses are painful, so its better to do the BP on their ankle. Some patients have also had ports placed in their non-access arm for shots/medications etc, and you can't do a BP on a port arm either, meaning you have to do it on their ankle.

The best thing to do is if you ever have a dialysis patient is to just ask them where they take the BPs during their treatment. Most patients will know when you ask them.