Association between Intra-Circuit Activated Clotting Time and Incidence of Bleeding Complications during Continuous Renal Replacement Therapy using Nafamostat Mesilate: a Retrospective Pilot Observational Study.

It has been proposed that anticoagulant activity during continuous renal replacement therapy with nafamostat mesilate can be monitored by using intra-circuit activated clotting time. However, it is still unclear whether activated clotting time would be useful for this purpose. We conducted a retrospective study and included 76 patients who required continuous renal replacement therapy using nafamostat mesilate. We obtained information for pre- and post-filter activated clotting times and bleeding complications. We calculated time-weighted average activated clotting time. We divided the patients into three activated clotting time groups (low, middle, high) according to the tertiles of pre- and post-filter activated clotting times. Regarding post-filter time-weighted average activated clotting time, the incidence of bleeding complications in the high activated clotting time group was significantly higher than those in the low and middle activated clotting time groups (p=0.04). The incidences of bleeding complications were not significantly different among the three groups according to pre-filter time-weighted average activated clotting time (p=0.35). In sensitive analysis, the duration on continuous renal replacement therapy without bleeding complications was significantly longer for filters with post-tw ACT<262 than for those with post-tw ACT≥262 (p=0.03). This result suggested that post-filter time-weighted average activated clotting time might be a good predictor of bleeding complications during continuous renal replacement therapy with nafamostat mesilate. Further study is required to refute or confirm our findings.