What is the proper procedure for transfusing platelets?

How to Transfuse Platelets

Platelets should be transfused using leukoreduced products (either single-donor apheresis or pooled whole blood-derived concentrates) at a standard dose of one apheresis unit or 4-6 pooled concentrates, administered through appropriate tubing with ABO compatibility when possible, stored at 20-24°C with continuous agitation, and used within 5 days of collection. 1

Product Selection and Equivalence

When leukoreduced products are available, whole blood-derived platelets and apheresis platelets should be used interchangeably as equivalent products. 1

• Both product types produce similar posttransfusion increments, hemostatic benefit, and side effects 1
• The choice between products can be based on availability and cost considerations, as pooled concentrates are typically less expensive in most centers 1
• Single-donor apheresis platelets are preferred when histocompatible platelets are needed for patients refractory to random-donor transfusions 1

Standard Dosing

Transfuse one apheresis unit (containing at least 3×10¹¹ platelets) or pool 4-6 whole blood-derived concentrates as the standard dose. 1, 2

• Higher doses (double standard) do not reduce bleeding risk or improve outcomes 1, 2
• Lower doses (half standard) are equally effective for hemostasis but require more frequent transfusions 1, 2
• The platelet dose has no effect on bleeding incidence when doses range between 1.1×10¹¹ and 4.4×10¹¹ platelets per square meter 1

Important Dosing Caveat

Verify the actual platelet content with your local blood supplier, as many centers split apheresis collections into 2-3 products, making the actual dose equivalent to only 4-5 pooled units rather than 6-9 units. 1

Product Preparation and Storage Requirements

Whole Blood-Derived Platelets

• Prepared by centrifugation using either the platelet-rich plasma (PRP) method (used in the United States) or buffy coat (BC) method (used in Europe, Australia, and Canada) 1
• Four to six buffy coats are pooled, diluted in plasma or platelet additive solution, and centrifuged at low speed 1
• Storage can be extended to 5 days if performed in closed systems 1

Apheresis Platelets

• Collected through a blood-cell separator system requiring approximately 1.5-2 hours and processing 4,000-5,000 mL of donor blood 1
• Each apheresis product has a volume of approximately 200 mL 1
• Most products now contain <5×10⁶ leukocytes and are considered leukoreduced 1

Storage Conditions (Critical)

Store all platelet products at 20-24°C using continuous gentle horizontal agitation in storage bags designed for O₂ and CO₂ exchange. 1

• Maximum storage time is 5 days from collection to transfusion due to bacterial contamination risk 1
• Never refrigerate platelets, as this destroys platelet viability 1

ABO Compatibility and Testing

Provide ABO-compatible platelet products whenever possible, though red cell cross-matching is not necessary. 1

• All products are labeled with ABO and Rh typing and tested for transfusion-transmitted diseases 1
• Incompatible plasma (e.g., O donor to A or B recipient) can cause hemolysis, particularly in children 1
• While clinically significant hemolysis is unusual in adults, inventory constraints may occasionally preclude ABO-compatible products 1

Prophylactic Transfusion Thresholds

Transfuse prophylactically when platelet count is ≤10×10⁹ cells/L in hospitalized adults with therapy-induced hypoproliferative thrombocytopenia. 1, 2

Procedure-Specific Thresholds

• Lumbar puncture: Transfuse when platelet count is <50×10⁹ cells/L 1, 2, 3
• Major elective non-neuraxial surgery: Transfuse when platelet count is <50×10⁹ cells/L 1, 2, 3
• Central venous catheter placement: Consider transfusion when platelet count is <20×10⁹ cells/L 1

Active Bleeding Management

In patients with active bleeding and severe thrombocytopenia, transfuse immediately to achieve hemostasis and target a platelet count above 20,000-30,000/μL. 2

• Maintain platelet count ≥40-50×10⁹/L through repeated standard-dose transfusions 2
• Increase transfusion frequency rather than dose, as higher doses do not improve outcomes 2
• Do not withhold transfusion based on poor initial response; active bleeding mandates continued support 2

Common Pitfalls to Avoid

• Do not assume prophylactic thresholds apply to bleeding patients—therapeutic goals are higher (≥20,000-50,000/μL depending on bleeding severity) 2
• Do not use outdated products—bacterial contamination risk increases significantly after 5 days of storage 1
• Do not transfuse without checking local blood supplier policies—apheresis unit splitting practices vary and affect actual platelet dose 1
• Consider HLA-matched platelets for alloimmunized patients who demonstrate poor response to standard transfusions 2
• Be aware that automated platelet counters may be inaccurate at extremely low counts—consider clinical context and recent count patterns 2