Comparison of Anticoagulant Effects of Different Doses of Nafamostat in Continuous Renal Replacement Therapy (CRRT) in the Intensive Care Unit (ICU)

Inclusion Criteria: 1. Age \& Gender: Aged 18 to 80 years, regardless of gender. 2. Clinical Indication: Admitted to the Intensive Care Unit (ICU) with a confirmed indication for Continuous Renal Replacement Therapy (CRRT) and an expected treatment duration of greater than 24 hours. 3. Coagulation Status: Normal coagulation function prior to CRRT initiation, defined as:International Normalized Ratio (INR) ≤ 1.5,Fibrinogen (FIB) ≥ 1.5 g/L,Activated Partial Thromboplastin Time (APTT) ≤ 45 seconds 4. Platelet Count: Platelet count (PLT) ≥ 50 × 10⁹/L. 5. Body Mass Index (BMI): 18.5 kg/m² ≤ BMI ≤ 25 kg/m². 6. Informed Consent: Written informed consent obtained from the patient or their legally authorized representative. Exclusion Criteria: 1. Hypersensitivity: Known allergy or hypersensitivity to Nafamostat Mesilate or any component of the formulation. 2. Active Bleeding: Presence of active bleeding or a high risk of bleeding that contraindicates anticoagulation (e.g., active gastrointestinal bleeding, intracranial hemorrhage, or recent major surgery with a high bleeding risk). 3. Pregnancy/Lactation: Pregnant or breastfeeding women. 4. Concurrent Anticoagulation: Current use of other systemic anticoagulants (e.g., unfractionated heparin, low molecular weight heparin, warfarin, or direct oral anticoagulants) that cannot be discontinued. 5. Concurrent Extracorporeal Support: Concurrent use of other extracorporeal life support or blood purification therapies that may interfere with coagulation assessment, such as Extracorporeal Membrane Oxygenation (ECMO), Intra-Aortic Balloon Pump (IABP), or Plasma Exchange (PE). 6. Severe Liver Dysfunction: Severe hepatic impairment (Child-Pugh Class C) or baseline total bilirubin levels exceeding 5 times the upper limit of normal. 7. Limited Life Expectancy: Expected survival time of less than 24 hours due to the progression of underlying disease. 8. Conflicting Trials: Current participation in another interventional clinical trial that may influence the outcomes of this study.