IMPACT OF PROPHYLACTIC-DOSE ENOXAPARIN ANTICOAGULATION ON ANTI-Xa LEVELS, BLEEDING AND EXTRACORPOREAL CIRCUIT THROMBOSIS IN PATIENTS ON CHRONIC INTERMITTENT HAEMODIALYSIS
Dr KIM LINH VAN1,2, Ms JULIANNE CHONG1, Ms LISA TIENSTRA1, Ms MARIA KONDA1,2, Dr RIANA VAN DER LINDE2, A/Prof VIVIEN CHEN1,2,3, Dr Shaundeep Sen1,3
1Concord Repatriation General Hospital, Concord, Australia, 2NSW Health Pathology, Concord , Australia, 3Faculty of Medicine and Health, University of Sydney, Concord, Australia
Aims: To assess the safety and efficacy of enoxaparin as an alternative to unfractionated heparin (UH) in the prevention of thrombosis in extracorporeal circuits (ECC) used for intermittent haemodialysis (IHD) by assessing anti-Xa levels and comparing them to clinical outcomes.
Background: Therapeutic anticoagulation (TA) is required during IHD to prevent clotting of the ECC. Whilst UH has been the most common agent used to achieve TA, there is increased use of the low molecular weight heparin (LMWH) enoxaparin. The evidence for safety and efficacy of LMWH across all IHD populations is lacking.
Methods:L 20 outpatients (15 male, mean age 70+/-3.4 years) receiving stable thrice weekly facility IHD, 5hr/session, were investigated. Patients were transitioned from UH infusion to enoxaparin single dose 40mg, or 60mg if weight > 100kg (2 patients). The first five patients had baseline then hourly anti-Xa and APTT measurements for the first session. All patients had measurement of APTT and anti-Xa levels at 0, 2.5 and 5hr for 6 consecutive IHD sessions, full blood counts sessions 1 and 4, and were monitored for clinical complications.
Results: There were no episodes of minor or major bleeding. Only two patients had streaking of the dialyser requiring increase in enoxaparin dose 40 to 60mg. Average anti-Xa levels across all 6 sessions at 0, 2.5 and 5hr were 0.038, 0.454 and 0.251IU/ml respectively. There was no evidence of accumulation of enoxaparin across the sessions (p=0.01).
Conclusions: In this small, short duration IHD study, 40-60mg single dose enoxaparin was safe and efficacious. Peak Anti-Xa concentrations achieved were comparable to previous studies’ suggested “optimal dosing”. The finding of anti-Xa levels >0IU/ml prior to first dose requires further investigation.