From the Guidelines
The workup for blood clotting disorders should begin with a thorough clinical history and physical examination, followed by laboratory testing based on whether you suspect bleeding or thrombotic disorders, with initial screening tests including complete blood count (CBC), prothrombin time (PT), activated partial thromboplastin time (aPTT), and fibrinogen levels, as recommended by the most recent study 1.
Initial Screening Tests
The initial screening tests for blood clotting disorders include:
- Complete blood count (CBC)
- Prothrombin time (PT)
- Activated partial thromboplastin time (aPTT)
- Fibrinogen levels
Additional Tests for Bleeding Disorders
For bleeding disorders, additional tests include:
- Von Willebrand factor antigen and activity
- Factor assays (particularly VIII, IX, XI)
- Platelet function tests
- Thromboelastography
Additional Tests for Thrombotic Disorders
For thrombotic disorders, testing should include:
- Protein C, protein S, antithrombin levels
- Factor V Leiden mutation, prothrombin gene mutation
- Lupus anticoagulant, anticardiolipin antibodies, and beta-2 glycoprotein antibodies
- D-dimer testing is useful for ruling out acute thrombosis
Genetic Testing
Genetic testing may be warranted for hereditary conditions like hemophilia or von Willebrand disease, as suggested by the study 1.
Timing of Testing
The timing of testing is important, as acute phase reactants can affect results, so testing should ideally occur when the patient is not acutely ill or on anticoagulants, as noted in the study 1.
Recent Guidelines
Recent guidelines, such as those from the European Society of Cardiology 1 and the American Heart Association/American Stroke Association 1, emphasize the importance of a systematic approach to identifying specific deficiencies or abnormalities in the coagulation cascade, allowing for targeted treatment of the underlying disorder.
Conclusion is not allowed, so the answer will be ended here.
From the Research
Workup for Blood Clotting Disorders
The workup for blood clotting disorders typically involves a combination of clinical assessment, laboratory tests, and imaging studies.
- Clinical assessment: A thorough medical history, physical examination, and family history are essential in identifying the cause of bleeding or clotting disorders 2.
- Laboratory tests: Routine screening tests include a complete blood cell count, platelet count, prothrombin time, and activated partial thromboplastin time 2.
- Specific tests: Depending on the suspected disorder, specific tests such as factor VIII, von Willebrand factor antigen, von Willebrand factor activity, and template bleeding time may be ordered 2.
Diagnosis of Specific Disorders
- Von Willebrand disease: Diagnosis is based on a combination of clinical findings, family history, and laboratory tests, including von Willebrand factor antigen, von Willebrand factor activity, and factor VIII levels 2.
- Factor V Leiden mutation and prothrombin gene mutation: These mutations can be identified through genetic testing and are associated with an increased risk of venous thromboembolism 3, 4.
- Protein C and protein S deficiencies: These deficiencies can be diagnosed through laboratory tests and are associated with an increased risk of thrombosis 3.
Laboratory Tests for Coagulation Activation
- Markers of coagulation activation, such as F1+2, TAT, and DDI, can be measured to assess the risk of thrombosis in patients with factor V Leiden mutation and/or G20210A prothrombin gene mutation 4.
- However, these tests have limited sensitivity and specificity, and their clinical utility is still being evaluated 4.