When I started in-center hemodialysis over nine years ago, the goal of the dialysis technicians was a pump speed of 500. This allowed the greatest volume of blood to be filtered and cleaned, and provided the highest level of clearance, the amount of cleaning that occurred during treatment.

After numerous trips to the vascular center for clots in my fistula, narrowing and routine semi-annual checkups, the doctor told me frequently that I should lower the pump speed during dialysis from 500 to 450 to help prevent damage to my fistula. I always responded that I have always run at 500, and I didn’t think I should lower my pump speed. Lowering my pump speed would also lengthen the amount of time I spent dialyzing.

I recently had problems with the Venus portion of my fistula, and it became totally unusable. This led to my having to start a new Venus fistula and button-hole (see my blog post https://nxstageusers.wordpress.com/2018/01/07/my-venus-buttonhole-finally-stopped-working-starting-a-new-fistula-and-a-new-venus-buttonhole/ for more details about this).

While forming my new Venus button-hole I had to start with size 17 (much smaller) needles and used a maximum run speed of 200. It took over fours and a half hours to dialyze the first day. The dialysis nurse who helped me with forming the new button-hole told me we could change the setting on my cycler called flow fraction, so that I could raise by dialysate rate, and it would allow me to run for my usual time of just over two hours even running at these extremely low pump speeds.

The next day I changed the cycler setting for flow fraction from 35 to 100. This allowed me to shorten my dialysis time by upping the dialysate rate until my run time showed just over two hours. I now start with a dialysate rate of 7.5, and raise it to 9.5 as I increase the pump speed from my starting speed of 200 to my new maximum of 450.

It’s important that you don’t raise your dialysate rate too high so that you don’t dialyze for at least two hours. If you don’t dialyze for at least two hours, your blood does not get properly cleaned during dialysis. And, the NxStage cycler has to run for a minimum of two hours anyway to remove the volume of water you enter.

Like the arterial physician, my dialysis nurse told me that all the new patients using NxStage use a maximum pump speed of 450. I have been running at 450 now for about two months. I was concerned that even though I use the higher flow fraction and dialysate rate, that I would not get the same high level of clearance that I did while running at pump speed 500.

Yesterday I had my monthly Nephrologist appointment, and my clearance was 2.8, the highest I have ever had. This immediately dispelled my fears that a lower pump speed while dialyzing would lower my blood clearance.

If you were like me, and learned to use NxStage with and continued to use a pump speed of 500, you should consider running at a reduced pump speed of 450 to protect your life-line, your fistula. My run times are now the same as when I ran at 500, and my clearance is even higher than anytime in the past.