Comparison of different heparin locking frequencies in patients with unremoved catheters after continuous renal replacement therapy in the intensive care unit: a prospective, open-label, randomized controlled trial protocol from China.

backgroundTo investigate the impact of different heparin locking frequencies on the incidence of catheter dysfunction among patients with unremoved dialysis catheters after continuous renal replacement therapy (CRRT) in the Intensive Care Unit (ICU) of Wuhan, China. The study aims to identify a relatively low-risk locking frequency for catheter dysfunction, evaluate its effects on maintaining catheter patency and preventing catheter-related bloodstream infections (CRBSI), and determine the optimal locking strategy that balances infection risk and catheter functionality. And conduct a cost-effectiveness analysis to assess the economic value of different locking frequencies, including total medical costs.

methodsThis is a prospective, open-label, parallel-group, single-center, superiority randomized controlled trial conducted at Zhongnan Hospital of Wuhan University. A total of 390 eligible patients will be enrolled and randomly assigned in a 1:1 ratio to either the intervention group (n = 195) or the control group (n = 195). INCLUSION CRITERIA: ① Patients with an unremoved dialysis catheter post-CRRT in the ICU; ② Age ≥ 18 years, regardless of gender; ③ Expected catheter indwelling time ≥ 72 h; ④ Signed informed consent by the patient or their legal representative. EXCLUSION CRITERIA: ① Pre-existing catheter dysfunction or infection before enrollment; ② Actual catheter removal during the study period; ③ Participation in another interventional study within the past two months. No stratification variables are used; simple randomization will be applied. Recruitment will be managed by the research team from the Department of Critical Care Medicine at Zhongnan Hospital of Wuhan University, including attending physicians, head nurses, and research nurses. The control group will receive heparin locking every 24 h until catheter removal, while the intervention group will be locked every 72 h. Both groups will use 1000 U/mL heparin solution (0.8 mL heparin + 4.2 mL normal saline) as the locking agent. PRIMARY OUTCOMES: Incidence of catheter dysfunction and catheter survival time. Safety endpoints: Rates of adverse events such as bleeding at the puncture site (persistent oozing, local hematoma), CRBSI, unplanned extubation, and air embolism. Cost-effectiveness outcomes: Total medical costs (including examination fees, treatment fees, material fees, medication fees, nursing labor costs) between the two groups. Outcome assessors and data analysts will be blinded. All analyses will follow the intention-to-treat principle based on randomized allocation, with missing data for primary outcomes excluded. DISCUSSION: This study represents the first prospective RCT comparing 24-h versus 72-h heparin locking frequencies in ICU patients with unremoved dialysis catheters post-CRRT. The findings are expected to provide high-quality evidence for selecting optimal catheter maintenance strategies, reducing nursing workload, and lowering healthcare costs for patients. In addition to clinical efficacy and safety, the integrated cost-effectiveness analysis will provide evidence for the economic feasibility of optimal locking strategies, supporting resource allocation decisions in clinical practice. TRIAL REGISTRATION {4}: Chinese Clinical Trial Registry. ChiCTR2500107820 . September 1, 2025.