Abstract: Objective This clinical trial was conducted to compare the anticoagulant efficacy and safety of nafmostat mesylate (NM) and heparin (HP) during double plasma molecular absorption system (DPMAS) treatment in patients with liver failure (LF). Methods 49 consecutive patients with LF or hyperbilirubinemia were encountered in You'an Hospital affiliated to Capital Medical University between April 2022 and March 2023, and all underwent at least twice DPMAS treatment. During the procedure, the anticoagulation was crossed by NM or HP once. The prothrombin time activity (PTA) and activated partial thromboplastin time (APTT) were monitored. Results Out of the 98 DPMAS treatment, the procedure successfully completed in 97 (99.0%), only discontinued once because of plugged pipes induced by insufficient anticoagulation of HP; the satisfactory anticoagulation rate in NM-managed group was 75.5%, significantly higher than 28.6%, and the over anticoagulation rate was 2.0%, much lower than 67.3%(P<0.05)in HP-intervened group; after the procedure, the PTA and APTT in NM anticoagulant group were 20.5(13.8, 38.0)% and 83.3(55.9, 138.8)s, significantly different compared to [19.5(14.6, 31.5)% and 400.0(303.3, 400.0)s, P<0.05] in HP anticoagulant group; there were no significant differences as respect to serum bilirubin, albumin levels and platelet counts between the two groups [(279.7±99.5)μmol/L, (24.4±4.2)g/L and 59.5(42.5, 119.0) ×10⁹/L vs. (271.7±98.1)μmol/L, 23.3(21.4, 26.6)g/L and 83.8±65.9×10⁹/L, respectively, P＞0.05]; 24 hours after DPMAS, the puncture skin haemorrhage was found in one case in HP anticoagulant group, and transient increased transmembrane pressure, or venous pressure or coagulation alert by the machine occurred in two cases in NM anticoagulant group. Conclusion The extracorporeal local anticoagulation of NM during DPMAS in patients with LF is efficacious and safer, and warrants further clinical investigation.

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