513 Continuous Heparin Infusion in Burn Patients on Continuous Renal Replacement Therapy

Abstract

Abstract Introduction Hyper-coagulopathy has been widely described in patients following burn injury. In burn patients with renal dysfunction requiring continuous renal replacement therapy (CRRT), citrate is commonly used to anticoagulate the circuit. However, if venous thromboembolism develops, or if the patient requires treatment-dose anticoagulation for acute coronary syndrome or atrial fibrillation, an unfractionated heparin (UFH) infusion can be used for anticoagulation. This study reviewed the use of heparin infusion in burned patients on concomitant continuous renal replacement therapy. Methods This study was a retrospective review of patients in a single burn center over six years. Patients were included if they were 18 years or older and receiving UFH as a continuous infusion for VTE, acute coronary syndrome (ACS), or new onset atrial fibrillation while on concomitant CRRT. Results Eight patients were included. Seven of eight patients reached a therapeutic aPTT level. The maximum rate of heparin infusion which was required to produce a therapeutic aPTT was 34 units/kg/hr while the minimum was 9 units/kg/hr. The patient requiring the highest heparin infusion rate met criteria for heparin resistance. Four of eight patients developed clinically significant bleeding while on heparin infusion. All four patients had some duration of concomitant citrate infusion during heparin infusion and all four were receiving heparin for VTE. Each of these patients required a heparin infusion rate of 24 units/kg/hr or greater to obtain therapeutic aPTT levels. Patients who did not have clinically significant bleeding had a maximum therapeutic heparin infusion rate of 22 units/kg/hr or less. Conclusions Heparin infusion can be used successfully in burn patients who are receiving concomitant CRRT, with the majority (7 of 8) of the patients in this study able to achieve a therapeutic aPTT level. Clinically significant bleeding occurred in 50% of patients and was associated with higher rates of heparin infusion (> 24 units/kg/hr) and the use of concomitant citrate infusion to anticoagulate the CRRT circuit. Heparin resistance appeared to be present in at least one patient in the study, with high doses of heparin required to achieve a therapeutic aPTT level.