Abstract: Objective This case-control study was conducted to compare the anticoagulant efficacy and safety of nafmostat mesylate (NM) and heparin (HP) during double plasma molecular absorption system (DPMAS) treatment. Methods 103 patients with hyperbilirubinemia were included in You'an Hospital affiliated to Capital Medical University between April 2022~March 2024 using prospective case-control research methods, and were divided into NM group and HP group with NM or HP in vitro anticoagulation during DPMAS treatment. Laboratory indicators, including total bilirubin (TBil), platelet(PLT) count, prothrombin activity(PTA) and partial thromboplastin time (APTT)were collected before and after DPMAS treatment, and complications such as various pressure parameters, alarms, bleeding or blockage during treatment. Results Out of the 103 DPMAS treatments, the procedure successfully completed in 102(99. 0% ), with only one treatment being discontinued because of plugged pipes induced by insufficient anticoagulation of HP; the satisfactory anticoagulation rate in NM-managed group was 88.2%, significantly higher than the 37.3% observed in HP-intervened group, and the over anticoagulation rate was 3.9%, much lower than the 58.8%(P<0.05) observed in HP-intervened group; During the treatment, the difference between the APTT at the venous and arterial end of the cardiopulmonary bypass line in the NM group [247(110, 286.3) vs. 0.0(0. 0, 55.5) s, P<0.05] significantly larger than the HP group; there were no significant differences in serum bilirubin, albumin levels and platelet counts between the two groups [(164.8±62.6) μmol/L, 5.7 (4.7, 7.8) g/L and 21 (11.5, 33.5) ×10⁹/L, vs. (174.3±64.9) μmol/L, 6.5 (5.1, 8.7) g/L and 15 (6, 24) ×10⁹/L, respectively, P>0.05]; During the course of treatment, severe pipe blockage was found in 1 case in HP anticoagulant group , the puncture skin haemorrhage was observed in 1 case in HP anticoagulant group, 1 case in the NM group, and transient increased transmembrane pressure, or venous pressure or coagulation alert by the machine occurred in 4 cases in NM anticoagulant group. Conclusion In the process of DPMAS treatment, NM demonstrates a better anticoagulation effect and higher safety compared to HP, which is worthy of further discussion. However, for patients with PTA≤40%, the optimal dose of NM requires further investigation.

Key words: Liver failure, Double plasma molecular absorption system, Nafamostat mesylate, Heparin