Seminars in thrombosis and hemostasis
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Semin. Thromb. Hemost. · Oct 2008
ReviewStandardization and clinical utility of thrombin-generation assays.
Thrombin generation is a key process that determines the extent of a hemostatic plug or a thrombotic process. The ensuing thrombin burst is crucial for the formation of a stable fibrin clot. During its active life, thrombin exerts a multitude of highly regulated actions on the blood and the vessel wall, including the clotting of fibrinogen. ⋯ Thrombin-generation assays not only provide an overall assessment of hemostasis but also target potential extrahemostatic effects of the generated thrombin, a potent agonist of a multitude of cellular activation pathways. Moreover, estimation of an individual's thrombin-generation potential may correlate more closely with a hypercoagulable or hypocoagulable phenotype when compared with traditional coagulation tests. In this review, we discuss to what extent thrombin generation can be expected to reflect the clotting function of blood, the development and use of different thrombin-generation assay systems suitable for detecting changes in the kinetics of thrombin generation, and the clinical utility of thrombin generation.
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Point-of-care (POC) testing in the field of hemostasis is rapidly expanding in many countries. This includes use of global tests of hemostasis in operating theaters and especially use of POC monitors for determination of the international normalized ratio (INR) for monitoring oral anticoagulant therapy. Issues related to internal quality control and external quality assessment for these devices are reviewed. Data from external quality assessment exercises involving users of several different POC-INR devices is described, and use of split samples where a patient sample is analyzed by both a POC device and by a conventional laboratory method is described.
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The term "QUALITY CONTROL" in laboratory medicine refers to all the procedures commonly used in clinical laboratories to monitor the routine performance of testing processes, to detect possible errors, and to correct problems before test results are reported. In particular, internal quality control (IQC) and external quality assessment (EQA) programs are used to evaluate and improve quality in laboratory medicine. Laboratory testing is necessary for the diagnosis and treatment of patients with hemostatic disorders. ⋯ Currently available data on analytical quality in coagulation testing not only demonstrates that quality is often unsatisfactory, but also highlights the need for more objective establishment of performances goals. This should be useful for better addressing both IQC and EQA programs. New challenges to EQA schemes for coagulation testing derive from the introduction of innovative tests, genetic analysis, and the need to assess not only analytical procedures but also all steps included in the total testing process.