Prefilled versus infused regional citrate anticoagulation during continuous renal replacement therapy on circuit lifespan: protocol for a randomised controlled trial.

introductionFor critically ill patients requiring continuous renal replacement therapy, regional citrate anticoagulation is the preferred strategy to maintain extracorporeal circuit patency. Current clinical practice relies on two citrate-based protocols, with the widely used but complex 4% trisodium citrate solution posing a hypernatraemia risk and haemofiltration replacement fluid of sodium citrate offering procedural simplification and a more physiological electrolyte profile. Direct prospective comparison of their circuit lifespan efficacy is currently unavailable. METHODS AND ANALYSIS: This single-centre, prospective, open-label, parallel-group randomised controlled trial will be conducted in China. 90 patients will be enrolled and randomly assigned (1:1) to receive anticoagulation with either citrate-based haemofiltration replacement fluid or 4% trisodium citrate solution, with all patients undergoing a standardised continuous venovenous haemofiltration protocol. The primary outcome is circuit lifespan, with a non-inferiority margin set at 2.43 hours. Secondary outcomes include the 72-hour circuit survival probability, duration of hospitalisation, and all-cause mortality rates at 28 and 90 days. The primary analysis will follow the intention-to-treat principle. ETHICS AND DISSEMINATION: The study protocol has been approved by the Biomedical Research Ethics Committee of West China Hospital, Sichuan University (Approval No. (2025)1157). Any subsequent amendments must be submitted to the same ethics committee for further review and approval prior to implementation. Furthermore, the findings of this trial will be disseminated through presentations at relevant national and international conferences and via publication in peer-reviewed scientific journals. TRIAL REGISTRATION NUMBER: Chinese Clinical Trial Registry ChiCTR2500106991.