title: Successful use of recombinant hirudin and its monitoring by ecarin clotting time in patients with heparin-induced thrombocytopenia undergoing off-pump coronary artery revascularization.
abstract: Refludan (lepirudin-rDNA for injection) is the first direct thrombin inhibitor approved by the United States FDA for anticoagulation to patients with heparin-induced thrombocytopenia (HIT). It was monitored by ecarin clotting time (ECT) assay in patients with HIT. Case histories and clotting parameters for three patients undergoing off-pump coronary artery revascularization procedure are discussed. The first patient received r-hirudin at a dose of 0.2 mg/kg intravenous (IV) bolus followed by 0.15 mg/kg/hour infusion. The second patient received 0.4 mg/kg IV bolus followed by infusion of 0.15 mg/kg/hour infusion. The third patient with renal failure received 0.2 mg/kg IV bolus followed by an infusion of 0.02 mg/kg/hour. Blood samples were drawn at baseline, 5 minutes post bolus and every 15 minutes during the coronary artery revascularization procedure. ECT was performed immediately on the citrated whole blood samples using the ECT cards in conjunction with the point-of-care, the thrombolytic assessment system (TAS) Analyzer (Pharmanetics, Raleigh, NC). The plasma samples were then analyzed for APTT and liquid ECT assay performed on a kinetic centrifugal analyzer (ACL 300 Plus). The ECT by cards was ideally maintained above 600 seconds during the surgical procedure. Additional boluses of Refludan were given as and when necessary (ECT < 600 sec) in order to maintain adequate anticoagulation. The calculated circulating concentrations of Refludan, following a bolus administration, based on the ECT cards, liquid ECT and APTT were 3.20 +/- 1.3, 3.51 +/- 1.35 and 2.02 +/- 1.19 microg/mL, respectively.
authors.affiliation: Department of Pathology, Loyola University Medical Center, 2160 S. First Ave., Building 102, Room 2646, Maywood, IL 60153, USA. oiqbal@lumc.edu
authors.forename: O
authors.initials: O
authors.lastname: Iqbal
authors.forename: M
authors.initials: M
authors.lastname: Tobu
authors.forename: S
authors.initials: S
authors.lastname: Aziz
authors.forename: M
authors.initials: M
authors.lastname: Gerdisch
authors.forename: M
authors.initials: M
authors.lastname: Da Valle
authors.forename: M
authors.initials: M
authors.lastname: Demir
authors.forename: D A
authors.initials: DA
authors.lastname: Hoppensteadt
authors.forename: S
authors.initials: S
authors.lastname: Ahmad
authors.forename: J M
authors.initials: JM
authors.lastname: Walenga
authors.forename: J
authors.initials: J
authors.lastname: Fareed
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D001780:Blood Coagulation Tests; D047549:Coronary Artery Bypass, Off-Pump; D010450:Endopeptidases; D005260:Female; D005343:Fibrinolytic Agents; D006493:Heparin / Q000008:administration & dosage / Q000009:adverse effects*; D006629:Hirudins / Q000008:administration & dosage*; D006801:Humans; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D011994:Recombinant Proteins / Q000008:administration & dosage*; D013921:Thrombocytopenia / Q000139:chemically induced / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants; D005343:Fibrinolytic Agents; D006629:Hirudins; D011994:Recombinant Proteins; D006493:Heparin; D010450:Endopeptidases; C020097:ecarin; C083544:lepirudin