Optimization of the Convective Dose in On-Line Hemodiafiltration: Prospective Interventional Cohort Study—Conducted at Soissons Hospital, France

TL;DR

A study in France found that a structured protocol can help most patients achieve better dialysis through on-line hemodiafiltration.

Contribution

A stepwise optimization protocol successfully increased convection volume in unselected dialysis patients under routine conditions.

Findings

Blood flow and dialyzer use improved significantly after protocol implementation.

Convection volume increased and remained high through six months of follow-up.

62.3% of patients achieved a convection volume of 23.5 L/session.

Abstract

Background and Objectives: On-line hemodiafiltration (OL-HDF) has been proposed as an alternative to conventional hemodialysis (HD) for patients with end-stage chronic kidney disease (CKD). Randomized controlled trials suggest that OL-HDF may reduce mortality, particularly when the convection volume (CV) exceeds 23 L/1.73 m2 per session. However, achieving this target depends on local practices and may be limited to selected populations. The CONVINCE trial reported a 97% success rate using a structured optimization protocol, but its applicability to unselected real-world populations remains uncertain. This study aimed to evaluate the incidence of high CV in OL-HDF among unselected patients managed under routine conditions with a standardized optimization protocol. Methods and Materials: This prospective cohort study (May–October 2024) included 67 unselected incident and prevalent patients undergoing HD or HDF in a hospital-based dialysis center. All patients were switched to post-dilution OL-HDF following the CONVINCE optimization protocol, which involved stepwise increases in blood flow, adjustment of filtration fraction, and optimization of session duration. Results: The mean age was 68.8 ± 14.9 years; 56.7% were male. Blood flow increased from 283 to 338 mL/min (p < 0.001), and the use of dialyzers > 2 m2 increased from 36% to 68% (p < 0.003). Kt/V improved from 1.22 to 1.6 (p < 0.01). CV increased by ~2 L from M1 onward and was sustained through M6, correlating positively with blood flow, session duration, and Kt/V (all p < 0.01). Conclusions: Stepwise optimization protocol enabled sustained achievement of high CV (23.5 L/session) in 62.3% of patients, improving dialysis adequacy.

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