What is the proper protocol for transfusing platelet concentrate to a patient, considering their blood type, medical history, and risk of bleeding or adverse reactions?

How to Transfuse Platelet Concentrate

Storage and Preparation

Platelet concentrate must be stored at 22°C with constant gentle agitation in an approved incubator and should never be refrigerated, as this damages platelet function. 1

• Transfusion should ideally commence within 30 minutes of removal from the platelet storage incubator 1, 2
• Each standard adult therapeutic dose contains 250-350 ml with a platelet count >2.4 × 10¹⁰/L per unit 1
• A standard dose should increase the patient's platelet count by approximately 30 × 10⁹/L 1, 2

Administration Technique

A standard adult therapeutic dose should be infused over 30 minutes through a standard blood administration set or platelet administration set incorporating a 170-200 μm filter. 1, 2

• Do not give platelets through a set that has already been used for red cells, as previously used sets may cause platelets to stick to residual red cells and reduce the effective transfused dose 1, 2
• No drugs should be added directly to the unit of platelets 1, 2
• The 30-minute infusion time represents the optimal balance between timely administration and preservation of platelet function 2
• Rapid infusion may increase the risk of adverse reactions, including transfusion-related acute lung injury (TRALI) and circulatory overload 2

Transfusion Thresholds

Prophylactic Transfusion (Non-Bleeding Patients)

For patients with therapy-induced hypoproliferative thrombocytopenia (chemotherapy/stem cell transplant), transfuse when platelet count is <10 × 10⁹/L. 1, 3

• This threshold is supported by high-quality evidence showing no increased bleeding risk compared to higher thresholds of 20 × 10⁹/L or 30 × 10⁹/L 1
• For patients with significant bleeding risk factors, consider transfusion at <20 × 10⁹/L 1
• For consumptive thrombocytopenia in adults without major bleeding, transfuse when platelet count is <10 × 10⁹/L 3
• For neonates with consumptive thrombocytopenia without major bleeding, transfuse when platelet count is <25 × 10⁹/L 3

Active Bleeding

For patients with active bleeding, transfuse to maintain platelet count >75 × 10⁹/L. 1, 4, 2

• For traumatic brain injury or severe bleeding, maintain platelet count ≥100 × 10⁹/L 2, 5
• For major hemorrhage in sepsis, maintain platelet count ≥50 × 10⁹/L 1

Procedural Thresholds

For invasive procedures, transfuse to achieve specific platelet count targets based on bleeding risk:

• Lumbar puncture: Transfuse when platelet count is <20 × 10⁹/L 3
• Central venous catheter placement (compressible sites): Transfuse when platelet count is <10 × 10⁹/L 3
• Low-risk interventional radiology procedures: Transfuse when platelet count is <20 × 10⁹/L 3
• High-risk interventional radiology procedures: Transfuse when platelet count is <50 × 10⁹/L 3
• Major nonneuraxial surgery: Transfuse when platelet count is <50 × 10⁹/L 5, 3

Dosing

Transfuse one standard apheresis unit or equivalent (pooled buffy coat from 4-6 whole blood donations) as the standard adult dose. 1

• Greater doses are not more effective, and lower doses (one-half standard) are equally effective for prophylaxis 1
• For severe bleeding, an initial dose of 4-8 platelet concentrates or one apheresis pack may be required 2
• The patient's platelet count should be repeated after transfusion to assess response 1, 2

Blood Type Considerations

Platelets do not have to be ABO-matched to the patient, but specific considerations apply:

• Group O platelets given to non-group O children should be selected to be high-titre negative 1, 2
• D-negative children and women of childbearing potential should receive D-negative platelets to prevent risk of developing immune anti-D 1, 2

Special Clinical Situations

When NOT to Transfuse

Do not transfuse platelets in the following situations:

• Consumptive thrombocytopenia due to Dengue without major bleeding 3
• Cardiovascular surgery patients without thrombocytopenia and without major hemorrhage, including those receiving cardiopulmonary bypass 3
• Nonoperative intracranial hemorrhage in adults with platelet count >100 × 10⁹/L, including those receiving antiplatelet agents 3
• Hypoproliferative thrombocytopenia in nonbleeding adults undergoing autologous stem cell transplant or with aplastic anemia (prophylactic transfusion not recommended) 3

Safety Considerations

The risk of bacterial infection transmission is 1 in 12,000, higher than other blood components due to storage at 22°C. 1, 2

• Bacterial screening before release helps reduce this risk 1, 2
• Monitor for transfusion reactions during the controlled 30-minute infusion 2
• Use warming devices for massive transfusion scenarios, but platelets stored at 22°C require less aggressive warming than red cells 1

Common Pitfalls to Avoid

• Never refrigerate platelets - this is the most critical error that damages platelet function irreversibly 1, 2
• Avoid using administration sets previously used for red cells 1, 2
• Do not transfuse based solely on bruising (ecchymoses) without evidence of active bleeding or severe thrombocytopenia 4
• Avoid unnecessary prophylactic transfusions at higher thresholds (>10 × 10⁹/L) in stable patients, as this increases donor exposure without reducing bleeding risk 1, 3