Individualized hemodialysis: Is similar hemodialysis adequacy possible using less water?

Background And Aim: There are over 60,000 hemodialysis (HD) patients in Türkiye, and the number of patients is increasing yearly. Dialysate flow rate (Qd) is a factor in HD adequacy. Approximately 150 L of water are consumed per session to prepare the dialysate. We aimed to investigate whether HD effectiveness can be achieved at a low Qd in different patient groups for the purpose of saving water.

Materials And Methods: This prospective study included 81 HD patients from 2 centers. The patients underwent an aggregate total of 486 HD sessions, including 3 sessions at a Qd of 500 mL/min and 3 sessions at a Qd of 300 mL/min for each patient. We used online Kt/V readings recorded at the end of each dialysis session to compare the effectiveness of these 2 types of HD session performed at a different Qd.

Results: The online Kt/V readings were similar between the standard (500) and low (300) Qd HD (1.51 ± 0.41 and 1.49 ± 0.44, respectively, p = 0.069). In the subgroup analyses, men had higher online Kt/V values at the standard Qd compared to the low Qd (1.35 ± 0.30 and 1.30 ± 0.32, respectively, p = 0.019), but the Kt/V values were not different for women. While the low Qd did not reduce online Kt/V in patients using small surface area dialysis membranes (1.75 ± 0.35 for 300 Qd and 1.75 ± 0.32 for 500 Qd, p = 0.931), it was associated with reduced online Kt/V in patients using large surface area dialysis membranes (1.12 ± 0.25 for 300 Qd and 1.17 ± 0.24 for 500 Qd, p = 0.006). The low Qd did not result in differences in online Kt/V among low-weight patients. However, online Kt/V values were better with the standard Qd in patients weighing 65 kg and above.

Conclusion: In our study, dialysis adequacy at a reduced dialysate flow was not inferior for women, patients with low body weight, or patients using small surface area membranes. Individualized HD at a reduced Qd of 300 mL/min in eligible patients can save 48 L of water per HD session and an average of 7500 L of water per year.