Question about arterial and venous pressures?

[Angiepkd]

Hi all! Day 2 of training/ dialysis went well. No pain with the 17 gauge needles, ran 3 hours at 250 again. However, my pressures were still high during the run. What are your recommendations for arterial and venous pressures? I was running over 200 venous, and got the arterial pressure down to 150 after maneuvering and flipping the needle. Training nurse is concerned, but willing to give it another try before sending me to the access center. Anyone have thoughts or experience? I am worried that those numbers are this high with such a low flow rate. The plan is to increase to 300 on Thursday.  Thanks for the help!  You guys are awesome and have helped me feel so prepared for everything!

[KatieV]

My new center is happy with venous pressures under 300 at a blood pump speed of 500.  They don't usually measure arterial as there usually isn't a pressure pod.  Your pressures do seem a little high.  Have they tried flipping the needle?  Maybe they just need some time to adjust?

[Angiepkd]

Thanks, Katie! The nurse has flipped needles, pushed, pulled, pillowed, taped and untaped etc., etc.  She is giving it a few treatments to maybe work itself out. Fingers crossed!

[Speedy1wrc]

How mature is your fistula? Using 17ga I am going to venture a guess it's fairly new? If so it may still take some time yet to mature. My fistula is 7 years old iand I have quite the aneurism. It did take a number of years off without use, but came back strong when needed again. Iremember having fairly low flow rates for awhile when it was new. As long as you can stay under the max limits and it "feels" good then take it a day at a time.

It's hard to compare apples to apples since you are using a small gauge needle. The needle itself will liimit blood pump speed and also it will affect pressure. I know with a 14ga needle you can go as high as 600ml/min but the max for 15ga needle which is what I use, is only 500mm/hg. I've seen suggested maximum flow rates for 17ga needles around 300ml/min but that isn't a hard fast rule.

That said with 15ga by 1" needles at a rate of 500ml/min my areterial is usually around 200 mm/hg to start then falls to around 180mm/hg by the end. My venous starts anywhere from 240mm/hg down to around 200mm/hg and it also drops to around 180mm/hg when all is said and done.

[Angiepkd]

Thanks Speedy! It helps to have some comparisons. My fistula is about a year old, but hasn't been used until now. I have been to the access center twice with this one. Once to have it ballooned and a follow up ultrasound. The vascular doc was in today while I was running and he wants me to come in next week so he can have a better look. I guess I will see what happens then.  My pressures were a little better today, but still high for the speed of 250.  Nothing is ever easy!  My prescribed flow rate is 400 to 450. I am inclined to stick with the lower number and stay on a little longer.  Needle size will increase to 16 gauge Friday and then to 15 the following week.  Thanks again!

[Speedy1wrc]

Good luck and keep us posted.

From my own personal experience it sounds like it's working halfway decently. It takes time on the machine to get it to grow. It sounds like it's gettig better but still needs some time. Getting larger needles will allow for more flow and also in and of itself will make for less resistence. It doesn't seem like much of a change, but the actual size difference is pretty big.

No need to rush it, take your time and it will get better.

[Bill Peckham]

The arterial is actually a negative number: how hard the machine is pulling the blood; the venous is a positive number: how hard the machine is pushing the blood. (note: dialysis both sucks and blows)

Where is your fistula? Is the arterial needle pointing into the blood flow or pointing with the blood flow? I haven't heard of it happening lately but the direction of blood flow can be hard to determine by sight with some fistulas, especially upper arm loops. I would first check to make sure the flow of the blood is known and that both needles are pointing with the flow.

My venous at 250 is about 100 - 120

[Zach]

(note: dialysis both sucks and blows)

How true!
 

[Angiepkd]

Thanks for responding, Bill. I have an upper arm fistula and both needles are pointed with the flow (i think). My fistula is large and pretty well developed considering it has never been used until now.  The general consensus is that I have a narrowing in one of the bends of my fistula. I am scheduled to go to the access center Wednesday, so I will see what the vascular doc says. Thanks for the help!

[Bill Peckham]

Just because, I'd confirm the direction of blood flow with the access center.


Hopefully the access center can identify and fix the issue if it is a narrowing.