Diagnostic strategies in disorders of hemostasis

Hemostasis is a complicated biological system, where the balance between procoagulation and anticoagulation processes maintains fluidity of blood through intact blood vessels and creates thrombi when it is needed to prevent bleeding from the impaired vessels. The modern model of hemostasis is divided into 2 principal phases, the first being defined as primary hemostasis which involves the platelet-vessel interplay, while the second, defined as secondary hemostasis, mainly involves coagulation factors and surfaces of activated cells. The activation and amplification of the coagulation cascade is regulated by natural inhibitors of coagulation. The blood clots which arise to prevent loss of blood must subsequently be broken down and the compact blood vessel wall must be restored. This process is called fibrinolysis. Bleeding and thromboses are manifestations of the impaired hemostatic balance. Detection of its cause is important for efficient treatment and prevention of the condition. This requires a combined evaluation of the family and personal history, a clinical anamnesis along with the evaluation of laboratory results. It is not reasonable or economical to perform all the available tests of hemostasis at the same time. It is recommendable to proceed from the global to the screening and then special tests and, through the process of elimination, obtain an explanation of the bleeding or prothrombotic phenotypes. The purpose of this report is to provide a brief overview of the principal causes of the hemostatic disorders and the practices which facilitate their diagnosis. Key words: diagnosis of hemorrhagic manifestations - diagnostics of thrombophilias - DIC diagnostics - hemophilia A - thrombopathy - von Willebrand disease.