Background: The objective of this work was to assess the impact of the decrease in dialysate flow rate on the dialysis dose delivered (spKt /V) to chronic hemodialysis patients and to estimate the resulting water saving.
Methods: It was a prospective 4-week-period study that included chronic hemodialysis patients with clinical and hemodynamic stability. The patients successively underwent hemodialysis with a dialysate flow rate of 500 ml / min, at 1, 1.2 and 1.5 times the blood flow rate. Each dialysate flow rate was applied for one week. During these 4 weeks, the following parameters were kept constant: duration of dialysis, blood flow rate, anticoagulation, membrane nature and surface.
Results: Forty-five chronic hemodialysis patients were included with a mean age of 48.4 ± 12.07 years. The weekly average spKt/V was statistically higher with a dialysate flow rate at 1.5 times the blood flow rate compared to the dialysate flow at 500 mL / min (p = 0.001). The proportion of patients achieving a standardized dialysis dose ≥ 1.4 was statistically higher with dialysate flow at 500 mL / min (64.4%) compared to dialysate flow at 1 or 1.2 times the blood flow rate which were 57.8% and 55.6%, respectively. It was statistically higher with a dialysate flow at 1.5 times the blood flow (93.3%) compared to the dialysate flow at 500 mL / min (p = 0.036). The dialysate volume used with a dialysate flow rate of 500 mL / min was higher compared to the other dialysate flow rates (p = 0.0001).
Conclusions: An adequate dialysis dose could be achieved with a dialysate flow rate of 1.5 times the blood flow rate, thereby saving significant amount of water.