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

OBJECTIVE: 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. MATERIALS AND METHODS: 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. RESULTS: 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). CONCLUSION: 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. TRIAL REGISTRATION: This study was registered in the Chinese Clinical Trial Registry ( www.chictr.org.cn ) under the registration number ChiCTR2200061065 on 15 June 2022.