What are the next steps in evaluating thrombocytopenia (low platelet count) in an elderly patient?

From the Guidelines

The next steps in evaluating thrombocytopenia in an elderly patient should include a comprehensive approach starting with a complete blood count with peripheral smear to confirm the low platelet count and assess for other cell line abnormalities. A thorough medication review is essential as many drugs can cause thrombocytopenia, including heparin, antibiotics, anticonvulsants, and certain cardiac medications. Basic laboratory tests should include liver function tests, renal function, coagulation studies (PT/INR, PTT), and assessment for vitamin B12 and folate deficiencies. Testing for potential underlying conditions is important, including hepatitis serology, HIV testing, and autoimmune markers like ANA and anti-platelet antibodies to rule out immune thrombocytopenia (ITP) 1. In elderly patients, a bone marrow examination may be necessary to exclude myelodysplastic syndrome or other bone marrow disorders. Additional specialized testing might include HIT antibodies if heparin exposure occurred, ADAMTS13 activity for suspected TTP, and DIC panel if there's evidence of consumption coagulopathy.

Some key points to consider in the evaluation and management of thrombocytopenia in elderly patients include:

• The use of corticosteroids may be appropriate in elderly patients with a platelet count at the lower end of the threshold, or those with additional comorbidities, anticoagulant or antiplatelet medications, or upcoming procedures 1.
• The American Society of Hematology 2019 guidelines for immune thrombocytopenia recommend against corticosteroids and in favor of management with observation in adults with newly diagnosed ITP and a platelet count of ≥ 30 x 10^9/L who are asymptomatic or have minor mucocutaneous bleeding 1.
• A systematic approach to identifying the underlying cause of thrombocytopenia, whether due to decreased production, increased destruction, or sequestration, is crucial in guiding appropriate management strategies.
• While awaiting results, bleeding precautions should be implemented, including avoiding antiplatelet medications, NSAIDs, and invasive procedures when possible.
• Treatment decisions should be based on the severity of thrombocytopenia, bleeding risk, and underlying cause rather than platelet count alone.

It's also important to note that the treatment of thrombocytopenia may involve the use of second-line therapies, such as splenectomy, immunosuppressive agents, or thrombopoietin receptor agonists, in patients who do not respond to first-line therapy or have contraindications to corticosteroids 1. However, the choice of therapy should be individualized based on the patient's specific clinical scenario, comorbidities, and preferences.

From the Research

Evaluation of Thrombocytopenia in Elderly Patients

The evaluation of thrombocytopenia in elderly patients involves several steps to determine the underlying cause of the condition.

• The first step is to exclude pseudothrombocytopenia by collecting blood in a tube containing heparin or sodium citrate and repeating the platelet count 2.
• If thrombocytopenia is confirmed, the next step is to distinguish acute from chronic thrombocytopenia by obtaining or reviewing previous platelet counts 2.
• A detailed review of medications and assessment for disorders that warrant urgent treatment is also necessary 3.
• The clinical approach requires evaluation of preexisting clinical conditions, and a systematic approach to diagnosis and management strategies should be followed 3.

Common Causes of Thrombocytopenia

Common causes of thrombocytopenia that require emergency hospitalization include heparin-induced thrombocytopenia, thrombotic microangiopathies, and the hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome 2.

• Nonemergency causes of thrombocytopenia include drug-induced thrombocytopenia, immune thrombocytopenia, and hepatic disease 2.
• In elderly patients, thrombocytopenia can be caused by various conditions, including primary immune thrombocytopenia, myelodysplastic syndrome, and drug-induced immune thrombocytopenia 3.

Management of Thrombocytopenia

The management of thrombocytopenia involves treating the underlying cause of the condition.

• 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 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.
• In patients with chronic thrombocytopenia, the use of platelet transfusions presents complex issues, including the risk of acute febrile episodes, alloimmunization, and infection 4.
• The role of prophylactic platelet transfusions in the palliative care setting should be considered, and the frequency of monitoring and transfusion threshold should be determined 4.