From the Guidelines
The initial step in the workup of a patient with thrombocytopenia is to perform a full blood count in primary care if the person is not acutely unwell, and same day test results can be obtained, to confirm thrombocytopenia and refer the patient to the emergency department immediately if necessary. This approach is based on the most recent guidance from the UK Haematology Expert Group, as outlined in the BMJ study 1.
When assessing people with suspected thrombocytopenia, it is crucial to ask about their vaccination history and take into account their overall clinical condition. If the patient is acutely unwell, they should be referred to the emergency department immediately. The full blood count is essential to confirm thrombocytopenia, and if present, the patient should be referred to secondary care for further evaluation.
In secondary care, additional tests such as D-dimer measurement, coagulation screen, including Clauss fibrinogen assay, and a blood film should be undertaken to confirm true thrombocytopenia and identify potential alternative diagnoses 1. The peripheral blood smear examination is also essential to evaluate platelet morphology and look for abnormalities in other cell lines that might suggest specific diagnoses.
It is also important to note that some patients with thrombocytopenia may have a normal platelet count at presentation, but it may subsequently fall below normal. Therefore, if a high clinical suspicion of thrombocytopenia remains, the platelet count should be repeated after two to three days.
The American Society of Hematology 2019 guidelines for immune thrombocytopenia also emphasize the importance of confirming the diagnosis and establishing care, determining platelet count trend and responsiveness to therapy, assessing additional bleeding risk, and initiating platelet-raising therapy 1. However, the most recent and highest quality study, as per the BMJ study 1, should be prioritized in guiding the initial step in the workup of a patient with thrombocytopenia.
Key considerations in the workup of thrombocytopenia include:
- Confirming the low platelet count with a repeat complete blood count (CBC)
- Evaluating the patient's vaccination history and overall clinical condition
- Referring the patient to secondary care for further evaluation if thrombocytopenia is confirmed
- Undertaking additional tests such as D-dimer measurement and coagulation screen to identify potential alternative diagnoses
- Repeating the platelet count after two to three days if a high clinical suspicion of thrombocytopenia remains.
By following this approach, healthcare providers can ensure that patients with thrombocytopenia receive prompt and appropriate care, which is critical in reducing morbidity, mortality, and improving quality of life.
From the Research
Initial Step in Thrombocytopenia Workup
The initial step in the workup of a patient with thrombocytopenia involves excluding pseudothrombocytopenia by collecting blood in a tube containing heparin or sodium citrate and repeating the platelet count 2.
Distinguishing Acute from Chronic Thrombocytopenia
If thrombocytopenia is confirmed, the next step is to distinguish acute from chronic thrombocytopenia by obtaining or reviewing previous platelet counts 2.
Evaluation of Thrombocytopenia
Key points to consider in the evaluation of thrombocytopenia include:
- Patients with platelet counts greater than 50 × 10^3 per μL are generally asymptomatic 3, 2
- Patients with platelet counts between 20 and 50 × 10^3 per μL may have mild skin manifestations such as petechiae, purpura, or ecchymosis 2
- Patients with platelet counts of less than 10 × 10^3 per μL have a high risk of serious bleeding 3, 2
- Common causes of thrombocytopenia include drug-induced thrombocytopenia, immune thrombocytopenia, and hepatic disease 3, 2
Treatment of Thrombocytopenia
Treatment of thrombocytopenia is based on the etiology and, in some cases, treating the secondary cause results in normalization of platelet counts 3. Some key treatment considerations include:
- Transfusion of platelets is recommended when patients have active hemorrhage or when platelet counts are less than 10 × 10^3 per μL, in addition to treatment (when possible) of underlying causative conditions 2
- Patients with platelet counts of less than 50 × 10^3 per μL should adhere to activity restrictions to avoid trauma-associated bleeding 2