Week 11 Tests for Fibrinolysis PDF

11 TESTS FOR FIBRINOLYSIS WHOLE BLOOD CLOT LYSIS TIME PRINCIPLE: Whole blood will clot spontaneously when collected in a glass tube without anticoagulant. The clot should remain intact for 48 at 37°C. dissolution of the clot prior to 48 hours is indicative of excessive systemic fibrinolysis EUGLOBUL...

11 TESTS FOR FIBRINOLYSIS WHOLE BLOOD CLOT LYSIS TIME PRINCIPLE: Whole blood will clot spontaneously when collected in a glass tube without anticoagulant. The clot should remain intact for 48 at 37°C. dissolution of the clot prior to 48 hours is indicative of excessive systemic fibrinolysis EUGLOBULIN LYSIS TIME Avoids the problems that arise from plasminogen inhibitors a more rapid and sensitive assav of lytic activity PRINCIPLE: Euglobulins are proteins that precipitate when plasma is diluted with water and acidified. They include plasminogen, plasmin, fibrinogen, and plasminogen activators. PROCEDURE: Diluted PPP + acid Euglobulin (precipitate) + Thrombin= clot Clot is incubated at 37°C REFERENCE RANGE: Lysis in less than 2 hours is indicative of increased fibrinolytic activity PROTAMINE SULFATE GELATION TEST A test for secondary (smaller) fibrin degradation products PRINCIPLE: Protamine sulfate replaces secondary degradation products from fibrin monomers and primary FDPs, resulting to a gel formation REFERENCE RANGE: Normally, no gel formation is seen ETHANOL GELATION TEST Less sensitive but more specific than protamine sulfate test in detecting soluble fibrin monomers and polymers in plasma PRINCIPLE: 50% ethanol causes soluble fibrin monomer to dissociate, resulting in polymerization of the monomers and subsequent gel formation REFERENCE RANGE: There should be no gel formation under normal conditions LATEX D-DIMER ASSAY Measures a specific fragment arising from degradation of fibrin (Ddimer) Measures fibrinolysis and not fibrinogenolyis (secondary fibrinolysis) Already positive after 4 hrs of DIC onset LATEX D-DIMER ASSAY PRIMARY SECONDARY EUGLOBULIN CLOT LYSIS TIME Shortened Normal or slightly shortened PLATELET COUNT Greater than 100x109/L Less than 100x109/L ANTITHROMBIN III ASSAY Normal Decreased D-DIMER Negative Positive ANTICOAGULANT THERAPY heparin Action: Enhances antithrombin III, inhibits thrombin Treatment: Protamine sulfate Monitoring: APTT used during coronary artery bypass graft surgery, during cardiac catheterization, and in several medical conditions Prolongs APTT and TCT warfarin Action: Antagonize Vit. K, induces formation of PIVKAs Treatment: Vit K. administration Monitoring: PT