ASN's Mission

To create a world without kidney diseases, the ASN Alliance for Kidney Health elevates care by educating and informing, driving breakthroughs and innovation, and advocating for policies that create transformative changes in kidney medicine throughout the world.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005


The Latest on X

Kidney Week

Please note that you are viewing an archived section from 2022 and some content may be unavailable. To unlock all content for 2022, please visit the archives.

Abstract: SA-PO419

Auto Flow Feature Reduces Dialysate Use While Maintaining Dialysis Adequacy Among In-Center Hemodialysis (HD) Patients

Session Information

Category: Dialysis

  • 701 Dialysis: Hemodialysis and Frequent Dialysis


  • Zhou, Meijiao, Fresenius Medical Care, Waltham, Massachusetts, United States
  • Ficociello, Linda, Fresenius Medical Care, Waltham, Massachusetts, United States
  • Mullon, Claudy, Fresenius Medical Care, Waltham, Massachusetts, United States
  • Anger, Michael S., Fresenius Medical Care, Waltham, Massachusetts, United States

Adjustment of dialysate flow rate (Qd) as a proportion of blood flow rate (Qb) may lower dialysate consumption. The Auto Flow (AF) feature on Fresenius Medical Care 2008T dialysis machines can make these adjustments automatically. Using real-world data, we investigated the use of the AF feature and its impact on dialysis adequacy among in-center HD patients.


Adult in-center HD patients converting from manual to AF (either 1.5 or 2.0 times the Qb) during 2021 at Renal Research Institute clinics were included. All patients had Kt/V measured 3 months before and after switching to AF and no change in vascular access, dialyzer types or prescribed Qb. Parameters were averaged over each 3-month period before and after switch, and comparisons between time periods were made using paired t-tests.


At AF switch, patients (n=48) had mean age of 64 years and vintage of 7 years. Most patients had a fistula (63%) and used Optiflux 180NRe (85%). 46% and 54% patients were switched to AF 1.5 and AF 2.0, respectively. After switch, on average, actual Qd reduced by 37 mL/min; based on the treatment time and actual Qd, we calculated that 8.6 L dialysate volume could be saved per patient per treatment (p<.0001). There was no statistically significant change in mean spKt/V, although there was a numeric increase after switch (table). Sub-analysis by AF 1.5 and 2.0, showed no change in spKt/V among patients switched to AF 1.5 (1.67) and an increase from 1.55 to 1.61 (p=0.06) among those switched to AF 2.0.


Use of the Auto Flow feature during HD maintained patients’ dialysis adequacy. Based upon actual Qd and treatment time, we can estimate that this would save, on average, 8.6 L of dialysate per patient per treatment (p<0.0001).

Parameters3-month before switch to AF3-month after switch to AFMean differenceP value
UKM spKt/V1.601.64+ 0.030.12
% UKM spKt/V≥ 1.2100%100%0/
Prescribed Qb, mL/min4284280/
Actual Qb, mL/min418419+1.40.17
Prescribed Qd, mL/min767758-8.70.61
Actual Qd, mL/min737700-37<.0001
Prescribed treatment time, min211212+0.80.14
Actual treatment time, min211210-1.10.32


  • Commercial Support –