Manual Versus Automated Biofeedback-Guided Strategies for Isonatremic Hemodialysis: A Real-World Comparative Study

Achieving neutral sodium balance during hemodialysis is essential to reduce sodium loading while preserving intradialytic hemodynamic stability. Automated biofeedback systems dynamically adjust dialysate sodium concentration using conductivity measurements, but their performance has rarely been compared with a manual individualized isonatremic sodium prescription in routine clinical practice. We compared these two individualized sodium management strategies.

This retrospective, single-center, real-world observational study included 49 adults undergoing maintenance online post-dilution hemodiafiltration between 2022 and 2024. A total of 14 653 dialysis sessions were analyzed, including 8164 sessions using automated biofeedback-guided sodium control targeting a plasma sodium change (ΔNa = 0 mmol/L) and 6489 sessions using a manual individualized isonatremic sodium prescription. Mixed-effects models were used to account for repeated sessions within patients.

Automated biofeedback maintained diffusive sodium transfer closer to neutrality than the manual approach (-0.02 ± 2.2 vs. -0.90 ± 2.7 g; adjusted β = 0.37, 95% CI: 0.11-0.62; p = 0.005), while total sodium removal was comparable between strategies. The machine-estimated change in plasma sodium was slightly greater with automated biofeedback (-1.6 ± 1.5 vs. -1.3 ± 1.8 mmol/L; adjusted β = -0.53; p = 0.03). Automated biofeedback was also associated with modestly lower interdialytic weight gain (2.12 ± 1.6 vs. 2.30 ± 1.9 kg; adjusted β = -0.11; p < 0.001) and pre-dialysis systolic blood pressure (140 ± 21 vs. 143.6 ± 22 mmHg; adjusted β = -3.57; p < 0.001). Poor intradialytic tolerance (20.3% vs. 24.9%; OR = 0.76, 95% CI: 0.712-0.816; p < 0.001) and symptomatic intradialytic hypotension (12.9% vs. 14.8%; OR = 0.86, 95% CI: 0.799-0.919; p < 0.001) were also modestly less frequent during the automated biofeedback period.

Automated biofeedback-guided sodium control provided more precise and reproducible sodium management than a manual individualized prescription and was associated with modest improvements in interdialytic weight gain, blood pressure, and intradialytic tolerance.