Abstract: Objective To explore the safety and effectiveness of nafamostat mesylate (NM) as an anticoagulant for hemodialysis, and its impact on the systemic coagulation function in patients undergoing maintenance hemodialysis (MHD).  Methods A prospective study was conducted on 12 MHD patients at the Department of Nephrology, The First People's Hospital of Chengdu from January to September 2022. Blood samples were collected at various time points: before dialysis at the arterial end, during dialysis (1h, 2h, 3h and 4h) and 15 minutes post-dialysis at the sites before the filter, after the filter and at the arterial end. NM concentration and activated clotting time (ACT) were measured in these blood samples.  Results At the time points of 1h, 2h, 3h and 4h during dialysis, the ACT values showed significant differences in the blood samples before the filter, after the filter and from arterial end (F=21.899, 27.464, 8.264 and 8.162 respectively; P<0.001, <0.001, =0.001 and =0.001 respectively); the ACT values of different sites at the same time point showed that the ACT value of arterial end was the lowest, followed by the value after filter and then the value before filter. At the time points of 1h, 2h, 3h and 4h during dialysis, the NM blood concentrations were significantly different in the blood samples before the filter, after the filter and from arterial end (F=46.547, 20.059, 16.582 and 16.687 respectively; P <0.001); the NM blood concentrations of different sites at the same time point showed that the NM blood concentration of arterial end was the lowest, followed by the value after filter and then the value before filter.  Conclusion Nafamostat mesylate effectively serves as an anticoagulant in the extracorporeal circulation during hemodialysis. It possesses the characteristics of high dialysis clearance rate and rapid metabolism in the body with a minimal impact on systemic coagulation status. It is a new choice of anticoagulant for patients undergoing hemodialysis with high risk of bleeding.

Key words: Nafamostat mesylate, Hemodialysis, Blood concentration, Coagulation function