From the Research
Before administering tranexamic acid (TXA), I recommend checking coagulation studies including prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen level, D-dimer, and complete blood count with platelet count. These tests help assess for existing intravascular clotting or hypercoagulable states that could be exacerbated by TXA. TXA is an antifibrinolytic agent that inhibits the breakdown of blood clots, so administering it to patients with active thrombosis could potentially worsen their condition. Elevated D-dimer levels may indicate ongoing thrombosis, while decreased fibrinogen might suggest consumption from disseminated intravascular coagulation (DIC) 1. Abnormal PT or aPTT could reflect underlying coagulopathy. Platelet count is important as thrombocytopenia may indicate consumption from clotting or other disorders. If these tests suggest active thrombosis, TXA should be used with extreme caution or avoided altogether, as it could increase the risk of thromboembolic complications such as deep vein thrombosis, pulmonary embolism, or arterial thrombosis.
The most recent and highest quality study on this topic is from 2014, which discusses the use of tranexamic acid, fibrinogen concentrate, and prothrombin complex concentrate in trauma-induced coagulopathy 2. However, the study does not provide specific guidance on laboratory tests to check before administering TXA. Therefore, the recommendation is based on the underlying pathophysiology of TXA and the potential risks of exacerbating intravascular clotting or hypercoagulable states.
In terms of specific laboratory tests, the following should be checked:
- Prothrombin time (PT)
- Activated partial thromboplastin time (aPTT)
- Fibrinogen level
- D-dimer
- Complete blood count with platelet count
These tests can help identify patients who may be at increased risk of thromboembolic complications and guide the safe use of TXA. It is essential to weigh the benefits and risks of TXA administration on a case-by-case basis, considering the patient's individual clinical scenario and laboratory results 2.