tokens: RESULTS : Unexpectedly high concentrations of argatroban were measured in these samples ( range , 0 - 32 microg / mL ), and a prolonged plasma argatroban half life ( t ( 1 / 2 )) of 514 minutes was observed ( published elimination t ( 1 / 2 ) is 39 - 51 minutes [< or = 181 minutes with hepatic impairment ]). CONCLUSIONS : Correlation of plasma argatroban concentration versus the patient ' s coagulation variables and clinical course suggest that prolonged elevated levels of plasma argatroban may have contributed to the patient ' s extended coagulopathy .