Objective: To describe a case of successful bivalirudin use as a prefilter anticoagulant in continuous venovenous hemofiltration (CVVH).
Case summary: A 30-year-old male was brought to the hospital by ambulance with an anterior communicating artery subarachnoid hemorrhage, signs of intraparenchymal hemorrhage, and hydrocephalus. During the patient's complicated hospital course, he developed acute renal failure requiring CVVH, as well as hepatic insufficiency (Child-Pugh class B). Unfractionated heparin was used as a prefilter anticoagulant. After he had a positive heparin-induced thrombocytopenia (HIT) antibody test, prefilter heparin was discontinued in favor of bivalirudin. Filter survival and systemic activated partial thromboplastin time (aPTT) values were compared between prefilter heparin (n = 5) and bivalirudin (n = 4). Filter survival was similar (median 26 h with heparin vs 37 h with bivalirudin; p = 0.52). Prefilter bivalirudin 1-2.5 mg/hour (0.009-0.023 mg/kg/h) was effective in maintaining systemic aPTTs that were 1-1.4 times the reference range. Serotonin release assay and subsequent HIT antibodies were negative. The patient's renal function improved and CVVH was discontinued.
Discussion: Critically ill patients requiring CVVH often need regional or systemic anticoagulation to prevent filter occlusion. In some patient populations, such as those with HIT or liver failure, prefilter heparin and regional citrate, respectively, may not be options. Alternative anticoagulants may be needed to avoid complications of frequent filter occlusions. The direct thrombin inhibitors (DTIs) lepirudin and argatroban have been used to maintain hemofilter patency, in small studies. Bivalirudin may have pharmacokinetic advantages over other DTIs when used in patients with hepatic and renal impairment. In our patient, bivalirudin provided a safe alternative to heparin therapy and was effective in maintaining hemofilter patency during CVVH.
Conclusions: Prefilter bivalirudin may be an option to prevent filter occlusion in patients requiring continuous renal replacement therapy. Future studies are needed to validate the safety and efficacy of bivalirudin as a prefilter anticoagulant.