Background/Aims: Anticoagulation of the extracorporeal circuit is essential for adequate haemodialysis (HD). Low molecular weight heparins (LMWHs) are safe and sufficient towards achieving this goal. In the Netherlands, dosage is based on bodyweight and adjusted based on clinical events. LMWH levels during dialysis can be quantified through measurement of the anti-Xa activity and a target range of 0.5-1.0 IU/mL has been proposed. We aimed to evaluate the practical value of the anti-Xa activity to guide LMWH dosage in HD patients. Additionally, the value of the activated partial thromboplastin time (APTT) was investigated. Methods: All prevalent adult HD patients of our dialysis clinic were included. APTT and anti-Xa activity were measured before, during and after 2 dialysis sessions. Clinical and dialysis characteristics, including LMWH dosage, were derived from digital patient charts. Results: Our final study cohort consisted of 83 patients. LMWH dosage during dialysis was appropriate for bodyweight in 61% of cases, of which 50% reached an anti-Xa activity within the putative target range of 0.5-1.0 IU/mL. Forty-six percent of patients had an anti-Xa activity >1.0 IU/mL. Anti-Xa levels during and after dialysis were significantly correlated (r = 0.803, p < 0.01). No thrombotic or haemorrhagic complications were observed in this study. Correlation of APTT with anti-Xa activity was poor. Conclusion: Anti-Xa activity measurements during dialysis can identify patients in whom LMWH dosage should be lowered in a subsequent dialysis session. Whether such an intervention leads to a decrease in haemorrhagic complications needs to be evaluated in prospective studies.

Günal AI, Duman S, Ozkahya M, Töz H, Asçi G, Akçiçek F, et al: Strict volume control normalizes hypertension in peritoneal dialysis patients. Am J Kidney Dis 2001;37:588-593.
European Best Practice Guidelines Expert Group on Hemodialysis, European Renal Association: Section V. Chronic intermittent haemodialysis and prevention of clotting in the extracorporal system. Nephrol Dial Transplant 2002;17(suppl 7):63-71.
Lim W, Cook DJ, Crowther MA: Safety and efficacy of low molecular weight heparins for hemodialysis in patients with end-stage renal failure: a meta-analysis of randomized trials. J Am Soc Nephrol 2004;15:3192-206.
Grau E, Sigüenza F, Maduell F, Linares M, Olaso MA, Martinez R, et al: Low molecular weight heparin (CY-216) versus unfractionated heparin in chronic hemodialysis. Nephron 1992;62:13-17.
Polkinghorne KR, McMahon LP, Becker GJ: Pharmacokinetic studies of dalteparin (Fragmin), enoxaparin (clexane), and danaparoid sodium (orgaran) in stable chronic hemodialysis patients. Am J Kidney Dis 2002;40:990-995.
Ouseph R, Ward RA: Anticoagulation for intermittent hemodialysis. Semin Dial 2000;13:181-187.
Sridharan S, Berdeprado J, Sivalingam M, Farrington K: Dalteparin dosing in high-flux haemodialysis and haemodiafiltration. Nephron Clin Pract 2013;122:53-57.
Verhave G, Weijmer MC, Jaarsveld BC Van: Anticoagulation with dalteparin and nadroparin in nocturnal haemodialysis. Neth J Med 2015;73:270-275.
Antistolling bij hemodialyse, 2012|Nederlandse Federatie voor Nefrologie. (cited January 3, 2017).
Pauwels R, Devreese K, Van Biesen W, Eloot S, Glorieux G, Vanholder R, et al: Bedside monitoring of anticoagulation in chronic haemodialysis patients treated with tinzaparin. Nephrol Dial Transplant 2014;29:1092-1096.
Nigten J, De Groot KA, Grootendorst DC, Koolen SL, Herruer MH, Schut NH: Pharmacokinetics of dalteparin during haemodialysis. Nephron Clin Pract 2013;124:179-183.
Dalteparine|Farmacotherapeutisch Kompas. (cited January 3, 2017).
Kitchen S, Theaker J, Preston FE: Monitoring unfractionated heparin therapy: relationship between eight anti-Xa assays and a protamine titration assay. Blood Coagul Fibrinolysis 2000;11:137-144.
Gosselin RC, Funk DM, Taylor JM, Francart SJ, Hawes EM, Friedman KD, et al: Comparison of anti-Xa and dilute Russell viper venom time assays in quantifying drug levels in patients on therapeutic doses of rivaroxaban. Arch Pathol Lab Med 2014;138:1680-1684.
Vandiver JW, Vondracek TG: Antifactor xa levels versus activated partial thromboplastin time for monitoring unfractionated heparin. Pharmacotherapy 2012;32:546-558.
Coene KL, van der Graaf F, van de Kerkhof D: Protocolled redefinition of the therapeutic range for unfractionated Heparin. Clin Appl Thromb Hemost 2016, Epub ahead of print.
Levine MN, Planes A, Hirsh J, Goodyear M, Vochelle N, Gent M: The relationship between anti-factor Xa level and clinical outcome in patients receiving enoxaparine low molecular weight heparin to prevent deep vein thrombosis after hip replacement. Thromb Haemost 1989;62:940-944.
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.