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What are the anticoagulation options for intermittent hemodialysis?

Nature Reviews Nephrology volume 7, pages 499–508 (2011)Cite this article

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Abstract

Prevention of clotting in the extracorporeal circuit was one of the major hurdles that had to be overcome to enable the expansion of routine outpatient hemodialysis to free-standing satellite centers and the home. Unfractionated heparin, the anticoagulant of choice for many years, is now being replaced by low-molecular-weight heparins (LMWHs) in an expanding number of countries. This trend is attributable to the ease and convenience of the administration of LMWHs coupled with their reliability and predictability of dosing. However, the choice of which LMWH to use depends on the duration and frequency of the dialysis sessions. For patients who are allergic to heparin or have heparin-induced thrombocytopenia, alternative anticoagulants—the direct thrombin inhibitors and heparinoids—are now available. These agents either have short half-lives (and therefore need to be delivered by infusions), or prolonged half-lives, which allows simple bolus administration, but increases the risk of drug accumulation, overdosage and hemorrhage. In patients at risk of bleeding, regional anticoagulants enable anticoagulation to be limited to the extracorporeal circuit. Prostanoids and nafamostat mesilate are expensive regional anticoagulants, and citrate infusions add complexity to the procedure. A citrate-based dialyzate has now been introduced that might enable heparin-free dialysis or reduce systemic anticoagulant requirements.

Key Points

  • Activation of leukocytes and platelets initiate extracorporeal clotting, a problem that has made it difficult to carry out dialysis in an outpatient setting

  • The anticoagulant effects of low-molecular-weight heparins are more predictable than those of unfractionated heparin

  • Unfractionated heparin and low-molecular-weight heparins remain the cheapest anticoagulants

  • Citrate-based dialyzate might permit short anticoagulant-free dialysis sessions

  • Anticoagulant-coated dialyzers might also enable short dialysis sessions to be performed without the use of systemic anticoagulants

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Figure 1: The Vroman effect.
Figure 2: Generation of thrombin via activation of leukocytes and platelets in the extracorporeal circuit.
Figure 3: Action of LMWHs on the traditional coagulation cascades, showing coagulation factors PKK and HMWK.
Figure 4: Plasma concentration of anti-factor Xa activity (anti-Xa) measured in blood taken postdialyzer.

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Davenport, A. What are the anticoagulation options for intermittent hemodialysis?. Nat Rev Nephrol 7, 499–508 (2011). https://doi.org/10.1038/nrneph.2011.88

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