# Efficacy and safety of regional citrate anticoagulation using calcium-containing replacement solution in different modalities of continuous renal replacement therapy: a randomized controlled trial

## TL;DR

This study compares the effectiveness and safety of different CRRT methods using citrate anticoagulation with calcium-containing fluids, finding that CVVHDF performs best.

## Contribution

The study provides new evidence on the efficacy of CVVHDF over CVVH and CVVHD in RCA-CRRT with calcium-containing fluids.

## Key findings

- CVVHDF showed significantly longer circuit lifespan compared to CVVHD and CVVH.
- CVVHDF had a lower incidence of severe venous chamber thrombosis and early circuit failure.
- RCA-CRRT with calcium-containing fluids was found to be safe and effective across all groups.

## Abstract

Regional citrate anticoagulation (RCA) is recommended as the first choice of anticoagulation strategies in continuous renal replacement therapy (CRRT). However, when using calcium-containing replacement fluid, whether RCA can achieve sufficient anticoagulant effect among different CRRT modalities remains unclear.

In this open-label, three-arm, randomized trial, AKI patients receiving RCA-CRRT with calcium-containing replacement fluids were randomized to continuous veno-venous hemofiltration (CVVH), continuous veno-venous hemodialysis (CVVHD) and continuous veno-venous hemodiafiltration (CVVHDF) groups from 2022 to 2023. The primary outcomes were circuit lifespan and early circuit failure. Secondary endpoints included the safety of the three groups and 30-day all-cause mortality.

A total of 121 patients were enrolled, with 40 in CVVH group, 40 in CVVHD group, and 41 in CVVHDF group. The circuit lifespan in CVVHDF group (70 h, IQR 65–72) was significantly longer than that in CVVHD (47 h, IQR 31.5–54) and CVVH group (64 h, IQR 46–71) (P < 0.001). Meanwhile, 27 circuits remained patent for 72 h (CVVH: 10/40, 25%; CVVHD: 1/40, 2.5%; CVVHDF: 16/41, 39.02%; P = 0.003). A significantly lower incidence of severe venous chamber thrombosis was observed in the CVVHDF group (2.4%, 1/41) relative to the CVVH (5%, 2/40) and CVVHD (50%, 20/40) groups (P < 0.001). Furthermore, early circuit failure (lifespan < 48 h) was observed in 35 circuits, occurring significantly more frequently in the CVVHD group (52.5%, 21/40) than in either the CVVH (22.5%, 9/40) or CVVHDF (12.2%, 5/41) groups (P = 0.004).

Our findings suggested that RCA-CRRT with calcium-containing replacement solution appeared to be safe and effective, with CVVHDF showing potentially prolonged filter survival compared to alternative modalities, which might support its consideration as a possible option in clinical practice.

This study was registered in the Chinese Clinical Trial Registry (www.chictr.org.cn) under the registration number ChiCTR2200061065 on 15 June 2022.

The online version contains supplementary material available at 10.1186/s12882-025-04565-7.