Manual Individualization of the Dialysate Flow According to Blood Flow: Effects on the Hemodialysis Dose Delivered and on Dialysate Consumption

Background: The objective of this study was to assess the impact of the decreasing dialysate flow rate (Qd) on the dialysis dose delivered (spKt/V) 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. Patients successively was dialysated with a Qd of 500 mL/min (Qd500), at 1 (mean Qd1 = 310 mL/min), 1.2 (mean Qd1.2 = 368 mL/min) and 1.5 (mean Qd1.5 = 464 mL/min) times the blood flow rate. Each dialysate flow rate was applied for one week. During these 4 weeks, the following parameters were 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 mean spKt/V was statistically higher with a Qd1.5 compared to the Qd500 (p = 0.001). The proportion of patients achieving a standardized dialysis dose ≥ 1.4 was statistically higher with Qd500 (64.4%) compared to Qd1 and Qd1.2 which were 57.8% and 55.6%, respectively. It was statistically higher with a Qd1.5 (93.3%) compared to Qd500 (p = 0.036). The dialysate volume used with a Qd500 was higher compared to the other Qd (p = 0.0001). Conclusion: An adequate dialysis dose could be achieved with a Qd1.5, allowing to significantly reducing amount of water.