It seems like whenever I've had a fistulagram to fix a stenosis in the venous area, I have problems afterwards with arterial pressures. The problems I was having with venous pressures have disappeared, but now I have arterial pressure issues. In other words, when the venous pressures are down the arterial pressures are up. I had the vascular surgeon recheck the arterial area of my fistula with an ultrasound and there are no detected issues.
I normally run at 450 pump speed on a NXStage Home Dialysis machine. When I start out, I run at 400 and then ramp up a little bit more over 10 minutes until I reach 450. By that time, the venous pressures have dropped to under 200 and the arterial pressure is already at 190's and approaching 200. It will hover there for around 1 hour and then the arterial just starts climbing and the venous starts dropping. About half way into treatment, I have to start trying to adjust needles because I will reach the point where I get an alarm because my arterial pressures have reached 220 and the venous has dropped down to 170's. Sometimes, but not always, a pillow made of gauze under the wings of the needle may help.
I have treated in center with nurse watching me cannulate just to make sure I am not doing something wrong. She just explained that I should go in at a 25 degree angle and then flatten out when I see a flash. This is what I think I am doing, but I still continue to have problems. She also mentioned that there may be "placque" blocking the flow and sometimes it might get caught at the needle opening.
I have also noticed that some areas in my fistula are harder to push in the needle then other areas. I have been using this fistula for over 5 years now. Are there other factors that affect cannulation and varying pressures that I don't know about? I am so frustrated with this. I did not seem to have these problem until more recently.
By the way, I have went to using 15 gauge sharps only, because my buttonholes were no longer cooperating. The sharps they supply us with are both the same for arterial and venous, both with eyes.
Hopefully you can help shed some light on this subject. Thank you.