Coagulation testing
Blood clotting tests are the tests used for diagnostics of the hemostasis system. Coagulometer is the medical laboratory analyzer used for testing of the hemostasis system. Modern coagulometers realize different methods of activation and observation of development of blood clots in blood or in blood plasma. Classification of blood clotting tests. Substantially all coagulometers used in laboratory diagnostics are based on the methods of testing of the hemostasis system created more than fifty years ago. The majority of these methods are good to detect defects in one of the hemostasis components, without diagnosing other possible defects. Another problem  of the actual hemostasis system diagnostics is the thrombosis prediction, i.e. sensitivity to the patient's prethrombotic state. All the diversity of clinical tests of the blood coagulation system can be divided into 2 groups: global (integral, general) tests, and «local» (specific) tests. Global tests. Global tests, also known as global coagulation assays (GCAs), characterize the results of work of the whole clotting cascade. They suit to diagnose the general state of the blood coagulation system and the intensity of pathologies, and to simultaneously record all attendant influences. Global methods play the key role at the first stage of diagnostics : they provide an integral picture of alterations within the coagulation system and allow predicting a tendency to hyper- or hypo-coagulation in general. Local tests. Local tests characterize the results of work of the separate components of the blood coagulation system cascade, as well as of the separate coagulation factors. They are essential for the possibility to specify the pathology localization within the accuracy of coagulation factor. A D-dimer (product of thrombi degradation) test can be specified separately. The rise of D-dimers concentration in the patient's blood states the possibility of the completed thrombosis. To obtain a  complete picture of the work of hemostasis by a patient, the doctor should have a possibility to choose which test is necessary. According to the type of the investigated object, the following complementary groups of methods can be specified: