Laboratory investigations

Laboratory investigations are an inevitable part of diagnosis of hemostatic disturbances. Screening analyses are usually performed in general clinical chemistry laboratories and are available 24 hours. They include platelet counts, PT(INR), aPTT, levels of fibrinogen, D‐dimer, and antithrombin. More detailed investigation of coagulation abnormalities is reserved for special coagulation laboratories and includes determination of single coagulation factors (FII, FV, FVII, FVIII, FIX, FX, FXI, FXII, FXIII); anticoagulants (antibodies against coagulation factors (particularly FVIII and FIX), and lupus anticoagulant); coagulation inhibitors (PS, PS); fibrinolysis factors (plasminogen, t‐PA) and inhibitors (plasmin inhibitor, PAI‐1) and functional platelet analyses. Additional analyses of markers of coagulation activation and global hemostatic assays may also be performed. Genetic investigations are primarily aimed at detection of mutation in genes for FVIII, FIX and VWF, and polymorphisms associated with thrombophilia (prothrombin mutation and FV Leiden mutation). To help clinicians choose appropriate tests in the diagnosis of hemostatic abnormalities several investigation “packages” may be offered (bleeding tendency, venous thrombosis, arterial thrombosis, hereditary thrombophilia).