Heparin‐induced thrombocytopenia during renal replacement therapy

Abstract

There is increasing awareness that antibodies to heparin/platelet factor 4 complex can develop in both those with acute renal failure treated with continuous forms of renal replacement therapy and, to a lesser extent, regular hemodialysis patients. Clinical manifestations include premature clotting of the extracorporeal circuit and increased central venous thrombosis with indwelling venous dialysis catheters, associated with thrombocytopenia and increased platelet activation. Nevertheless, a minority of patients who develop heparin/platelet factor 4 antibodies do not have thrombocytopenia or thrombosis. When systemic anticoagulation is also required to treat venous thrombosis, then synthetic heparinoids or the direct thrombin inhibitors argatroban or recombinant hirudins are the agents of choice. Neither the synthetic heparinoids nor hirudin, however, are without their own problems, in that a minority of patients may have cross-reacting antibodies against the currently available heparinoids, and antibodies may similarly develop against recombinant hirudin, in this case leading to a potentiation of anticoagulant activity and increased risk of hemorrhage.

Use and Safety of Unfractionated Heparin for Anticoagulation During Maintenance Hemodialysis

“…This typically occurs within the first 4 days of starting heparin therapy and thus is seen in incident hemodialysis patients. 64 The thrombocytopenia is mild, with average platelet levels of 100 × 10 9 per 1 L of blood, and typically resolves with time. No antibodies are formed, and heparin therapy does not need to be stopped.…”

Review article: Low‐molecular‐weight heparin as an alternative anticoagulant to unfractionated heparin for routine outpatient haemodialysis treatments

“…There are two types of thrombocytopenia associated with the administration of heparins. First, type I heparin‐associated thrombocytopenia, which is often observed during the first few days of starting dialysis, due to heparin activation of platelet factor 4 surface receptors, and has no clinical significance 19 . Whereas type II heparin‐induced thrombocytopenia is antibody mediated, with a strong association of arterial, venous and/or dialysis circuit thrombosis.…”

The rationale for the use of low molecular weight heparin for hemodialysis treatments

“…Studies which have compared with LMWHs with UFH, have reported shorter needle site bleeding times post dialysis, with either similar or less circuit clotting and bleeding episodes than UFH, and improved urea clearances due to reduced dialyzer membrane fouling and fewer cases of heparin induced thrombocytopenia …”