Effect of targeted versus fixed dosing of nafamostat mesylate on filter life in patients undergoing continuous renal replacement therapy

Nafamostat mesylate (NM) is a commonly used anticoagulant in continuous kidney replacement therapy (CKRT) in Japan and South Korea. NM has been empirically infused at fixed doses (10–20 mg/h) without monitoring. In this single-center before-and-after study, we designed post-filter activated partial thromboplastin time (aPTT)-based targeted NM dosing protocol for CKRT and evaluated its efficacy and safety. The targeted NM dosing protocol involved titrating the NM dose (2.5–5 mg/h) to maintain the post-filter aPTT between 46 and 70 s. Efficacy was assessed by comparing filter lifespan before and after protocol implementation. Safety was evaluated based on changes in the incidence of bleeding complications, leukopenia, and hyperkalemia. Linear mixed-effects and Cox proportional hazards models were used, as appropriate. In total, 151 (before; 91, after; 60) patients received NM-CKRT anticoagulation (68.9% men, mean ages; 68.2 ± 14.2 years). Patient demographics and disease severity were similar before and after protocol implementation. During the intervention, 74.3% of filters reached the target aPTT levels. Compared with fixed dosing, post-filter aPTT-based targeted NM dosing extended the filter life by 4.5 (95% confidence interval; 1.5–7.5) h among filters that achieved the target aPTT levels, without compromising safety issues. Further validation across diverse centers is required.