Regional citrate anticoagulation combined with nafamostat mesylate for continuous kidney replacement therapy in septic acute kidney injury patients: protocol for a prospective, three-arm, randomised controlled study (RCNM-CKRT).

Introduction: Extracorporeal circuit (EC) clotting remains a major challenge in continuous kidney replacement therapy (CKRT). While regional citrate anticoagulation (RCA) is recommended first-line, nafamostat mesylate (NM) offers an alternative with potential anti-inflammatory benefits. This trial aims to compare the effects of RCA, NM and their combination on EC lifespan during CKRT in critically ill acute kidney injury (AKI) patients with sepsis.

Methods and analysis: This is a single-centre, prospective, three-arm, open-label, randomised controlled trial. Critically ill adult patients with AKI with sepsis requiring CKRT will be enrolled. Participants will be randomly assigned (1:1:1) to receive RCA, NM or combined RCA+NM anticoagulation. The primary outcome is EC lifespan. Secondary outcomes include EC survival rates, patient mortality, inflammatory biomarker levels and safety events (eg, bleeding, citrate accumulation). The sample size of 258 patients (86 per group) was calculated to detect a significant difference in the primary outcome with 90% power. Analysis will follow the intention-to-treat principle, using Kaplan-Meier survival analysis and Cox regression for the primary outcome.

Ethics and dissemination: The RCNM-CKRT trial has been approved by the Biomedical Ethics Review Committee of West China Hospital, Sichuan University. We plan to present the results of our research at an international conference and publish in a peer-reviewed journal. The study data will be available on request, ensuring transparency and accessibility.Trial registration number:ChiCTR2600121436; Pre-results.