Does the Blood Pump Flow Rate have an Impact on the Dialysis Dose During Low Dialysate Flow Rate Hemodialysis?

We conducted a prospective study to assess the impact of the blood pump flow rate (BFR) on the dialysis dose with a low dialysate flow rate. Seventeen patients were observed for 3 short hemodialysis sessions in which only the BFR was altered (300,350 and 450 mL/min). Kt/V urea increased from 0.54 ± 0.10 to 0.58 ± 0.08 and 0.61 ± 0.09 for BFR of 300, 400 and 450 mL/min. For the same BFR variations, the reduction ratio (RR) of β2microglobulin increased from 0.40 ± 0.07 to 0.45 ± 0.06 and 0.48 ± 0.06 and the RR phosphorus increased from 0.46 ± 0.1 to 0.48 ± 0.08 and 0.49 ± 0.07. In bivariate analysis accounting for repeated observations, an increasing BFR resulted in an increase in spKt/V (0.048 per 100 mL/min increment in BPR [p < 0.05, 95% CI (0.03-0.06)]) and an increase in the RR β2m (5% per 100 mL/min increment in BPR [p < 0.05, 95% CI (0.03-0.07)]). An increasing BFR with low dialysate improves the removal of urea and β2m but with a potentially limited clinical impact.