title: Effects of unfractionated heparin, low-molecular-weight heparin, and heparinoid on thromboelastographic assay of blood coagulation.
abstract: Thromboelastography (TEG) has been used increasingly as an intraoperative hemostasis monitoring device. Low-molecular-weight heparins are given increasingly to reduce the development of antibodies against the heparin-platelet factor 4 complex, and heparinoids are given to patients who have developed the antibody. We studied the effect of unfractionated heparin, a low-molecular-weight heparin (enoxaparin sodium [Lovenox]), and a heparinoid (danaparoid sodium [Orgaran]) on blood clotting assayed with TEG (TEG clotting) in vitro and the efficacy of protamine sulfate and heparinase for reversing the effect. Heparin, enoxaparin, and danaparoid all caused a dose-dependent inhibition of TEG clotting of normal blood. Concentrations of enoxaparin and danaparoid that totally inhibited TEG clotting only minimally prolonged the activated partial thromboplastin time. While inhibition of TEG clotting by heparin and enoxaparin was reversed by protamine sulfate and heparinase, inhibition by danaparoid was reversed only by heparinase. Abnormal TEG clotting was observed in patients receiving enoxaparin whose plasma level of the drug was more than 0.1 antiXa U/mL. However, the degree of TEG abnormality did not always coincide with plasma levels of the drug.
authors.affiliation: Hemostasis and Rapid Response Laboratories, Northwestern Memorial Hospital, Chicago, IL, USA.
authors.forename: K
authors.initials: K
authors.lastname: Zmuda
authors.forename: D
authors.initials: D
authors.lastname: Neofotistos
authors.forename: C H
authors.initials: CH
authors.lastname: Ts'ao
mesh_terms: D000906:Antibodies / Q000097:blood; D000925:Anticoagulants / Q000494:pharmacology*; D001323:Autoantibodies / Q000097:blood; D001777:Blood Coagulation / Q000187:drug effects*; D002809:Chondroitin Sulfates / Q000494:pharmacology; D003871:Dermatan Sulfate / Q000494:pharmacology; D004338:Drug Combinations; D017984:Enoxaparin / Q000494:pharmacology*; D006493:Heparin / Q000276:immunology / Q000494:pharmacology*; D019763:Heparin Lyase / Q000494:pharmacology; D006496:Heparinoids / Q000494:pharmacology*; D006497:Heparan Sulfate / Q000494:pharmacology; D006801:Humans; D010314:Partial Thromboplastin Time; D010978:Platelet Factor 4 / Q000276:immunology; D011479:Protamines / Q000494:pharmacology; D011517:Prothrombin Time; D013916:Thrombelastography
chemical_list: D000906:Antibodies; D000925:Anticoagulants; D001323:Autoantibodies; D002809:Chondroitin Sulfates; D003871:Dermatan Sulfate; D004338:Drug Combinations; D017984:Enoxaparin; D006493:Heparin; D019763:Heparin Lyase; D006496:Heparinoids; D006497:Heparan Sulfate; D010978:Platelet Factor 4; D011479:Protamines; C035838:danaparoid