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Disseminated Intravascular Coagulation (Dic) And Related Syndromes
Published in Genesio Murano, Rodger L. Bick, Basic Concepts of Hemostasis and Thrombosis, 2019
Like the prothrombin time and partial thromboplastin time, the thrombin time can also be normal or “super normal”. Performance of a thrombin time and, alternatively/additionally, a reptilase time can add additional information if the resultant thrombin time clot (or reptilase time clot) is observed for evidence of lysis for 5 to 10 min. To observe the clot is of no additional expense, requires a minimum of laboratory time, is faster than plasminogen/plasmin assays or a euglobulin lysis time and provides evidence for significant fibrino(geno)lysis, thus aiding the diagnosis. A reptilase time is often helpful as a baseline when diagnosing DIC, since it is one of the few laboratory modalities that can be used to follow the patient with acute DIC once heparin has been given.
Disseminated Intravascular Coagulation
Published in Hau C. Kwaan, Meyer M. Samama, Clinical Thrombosis, 2019
Thiti Jaojaroenkul, Hau C. Kwaan
The presence of FDP may be detected by a prolongation of the thrombin time, but this test is not specific for FDP determination since heparin can also prolong thrombin time. Other coagulants such as peptides extracted from snake venom (Ancrod and Reptilase) are not affected by heparin, but by FDP, and may be used for clotting the fibrinogen. Thus, the Ancrod time or Reptilase time has been used instead of the thrombin time for testing FDP effects.68,69
Case 84
Published in Atul B. Mehta, Keith Gomez, Clinical Haematology, 2017
Common causes of a prolonged thrombin time (TT) are heparin contamination and a deficiency of fibrinogen. As the TT is very sensitive to heparin, it is quite possible for it to be prolonged without a rise in activated partial thromboplastin time (APTT). The reptilase time is insensitive to heparin and so this possibility is excluded because the reptilase time is also prolonged. Other causes include an inhibitor of fibrinogen cleavage, such as fibrinogen degradation products, or a low albumin that causes an artificial prolongation.
Testing strategies used in the diagnosis of rare inherited bleeding disorders
Published in Expert Review of Hematology, 2023
Deficiencies of coagulation factors in the common coagulation pathway prolong both the PT and APTT; however, reagent sensitivity affects the degree of prolongation (Figure 2). The PT/APTT tests are not sensitive to mild-to-moderate fibrinogen deficiency; therefore, specific fibrinogen assays measuring fibrinogen function (Clauss assay) should initially be performed with reflexive PT-derived (antigenic) assays to classify the type of deficiency; thrombin and reptilase time tests are more sensitive but not specific and add to the diagnosis of fibrinogen disorders. In addition to bleeding, some subtypes of congenital fibrinogen deficiency pose a risk for unprovoked or provoked thrombosis [76]. FV is a labile factor, and improper specimen processing/transportation may result in an artifactual reduction in measured levels; thus, repeat testing is essential to confirm a congenital deficiency state.