What are the guidelines for platelet transfusions in patients with thrombocytopenia?

From the Guidelines

Platelet transfusions are generally recommended for patients with thrombocytopenia when platelet counts fall below 10 × 10^9 cells/L or less to reduce the risk for spontaneous bleeding, as suggested by the AABB guidelines 1.

Key Recommendations

• The AABB recommends transfusing hospitalized adult patients with a platelet count of 10 × 10^9 cells/L or less to reduce the risk for spontaneous bleeding 1.
• For patients undergoing invasive procedures, higher thresholds are used: 50 × 10^9 cells/L for most procedures and 80,000-100,000/μL for neurosurgery or ocular surgery.
• Actively bleeding patients typically require transfusion to maintain counts above 50,000/μL.
• The standard adult dose is one unit of apheresis platelets or 4-6 units of pooled platelets, which should increase the platelet count by approximately 30,000-50,000/μL.

Considerations

• Transfusions should be ABO-compatible when possible, and CMV-negative products are preferred for immunocompromised patients.
• Refractoriness to platelet transfusions may develop due to alloimmunization, requiring HLA-matched platelets.
• Prophylactic transfusions are not recommended for immune thrombocytopenia (ITP) unless there is active bleeding, as these platelets are rapidly destroyed.
• The effectiveness of transfusion should be assessed with a post-transfusion platelet count performed 10-60 minutes after completion.

Risks

• Platelet transfusions carry risks including febrile reactions, allergic responses, transfusion-related acute lung injury, and infection transmission, so they should be used judiciously according to these guidelines 1.

From the Research

Platelet Transfusion Guidelines

The guidelines for platelet transfusions in patients with thrombocytopenia are as follows:

• For hypoproliferative thrombocytopenia in nonbleeding patients receiving chemotherapy or undergoing allogeneic stem cell transplant, platelet transfusion is recommended when platelet count is less than 10 × 10^3/μL 2.
• For consumptive thrombocytopenia in neonates without major bleeding, platelet transfusion is recommended when platelet count is less than 25 × 10^3/μL 2.
• In patients undergoing lumbar puncture, platelet transfusion is recommended when platelet count is less than 20 × 10^3/μL 2.
• In patients with consumptive thrombocytopenia due to Dengue without major bleeding, platelet transfusion is not recommended 2.
• For hypoproliferative thrombocytopenia in nonbleeding adults undergoing autologous stem cell transplant or with aplastic anemia, prophylactic platelet transfusion is not recommended 2.
• In adults with consumptive thrombocytopenia without major bleeding, platelet transfusion is recommended when platelet count is less than 10 × 10^3/μL 2.
• In adults undergoing central venous catheter placement in compressible anatomic sites, platelet transfusion is recommended when platelet count is less than 10 × 10^3/μL 2.
• In adults undergoing interventional radiology, platelet transfusion is recommended when platelet count is less than 20 × 10^3/μL for low-risk procedures and less than 50 × 10^3/μL for high-risk procedures 2.
• For adults undergoing major nonneuraxial surgery, platelet transfusion is recommended when platelet count is less than 50 × 10^3/μL 2.

Restrictive Transfusion Strategies

Restrictive transfusion strategies are recommended as they reduce the risk of adverse reactions, mitigate platelet shortages, and reduce costs 2, 3, 4.

• A selective literature search suggests that a more restrictive transfusion strategy is justified 3.
• Recent randomized trials have demonstrated that current practices may be suboptimal in a number of ways, and that a therapeutic rather than a prophylactic strategy of transfusion for bleeding manifestations only may be equally safe for most patients 4.
• The platelet count threshold for prophylactic transfusion can be as low as 10,000/µL 4.

Special Considerations

• In patients with inherited defects of platelet function or acquired defects such as due to drugs or uremia, the platelet count is usually normal and prophylactic transfusion is not recommended 5.
• For patients with idiopathic thrombocytopenic purpura, platelet survival is short and transfusion is useful only for severe bleeding 5.
• In intensive care unit patients, thrombocytopenia is very common and identification of the underlying cause is key for management decisions in individual patients 6.
• Platelet transfusion might be indicated in patients with impaired platelet production or increased platelet destruction, but could be deleterious in patients with increased intravascular platelet activation 6.