Laboratory parameters of the 1st order – obligatory laboratory tests.
- D-dimers – acute diagnosis of suspected fresh venous thrombosis (see also under “Physical examination” Wells score to determine clinical probability of venous thrombosis, DVT)[positive D-dimers are not specific for thrombosis or pulmonary embolism; however, negative D-dimers exclude thrombosis or pulmonary embolism with more than 99% probability]Diagnostic procedure depending on Wells score:
- High probability → immediate diagnostic imaging: CTPA (computed tomography of the pulmonary arteries)/V/P scintigraphy (ventilation/perfusion scintigraphy).
- Low or moderate probability → determination of D-dimers (if positive → compression phlebosonography).
- Platelets (thrombocytes)
- Fibrinogen – due topossible dysfibrinogenemia.
- Protein C deficiency
- Protein S deficiency
- Antithrombin III deficiency (AT III)
- Factor V Leiden mutation – so-called APC resistance (APC genotyping).
- Factor II mutation (prothrombin mutation).
- Factor VIII elevation
- Hyperhomocysteinemia
Laboratory parameters 2nd order – depending on the results of the history, physical examination, etc. – for differential diagnostic clarification.
- Auto-Ak against cardiolipin (phospholipid antibodies) – associated with venous or arterial thrombosis/vascular occlusion (antiphospholipid syndrome).
- PAI (plasma activator inhibitor).
Predictive laboratory parameter
- Mean platelet volume (MPV) [↑]:
- Male: Age, cardiovascular risk factors such as smoking and hypertension (high blood pressure), and elevated glucose (blood sugar) levels are associated with higher mean platelet volume.
- Woman: menstruation and hormonal contraceptives.
Increased platelet volume is associated with increased risk of cardiovascular disease and thrombosis and increased mortality (mortality).
