Platelet transfusion

    • Platelet indication poster

      Platelet dose, administration and storage poster 


      Platelets

      Platelets are small, disc shaped cells that have a critical role in helping our blood clot and stop bleeding. When there is a break in the vascular endothelium, a process of platelet activation occurs and the platelets change shape and aggregate to form a platelet plug.  

      Platelets are commonly transfused to patients with low platelet counts or patients with platelet dysfunction who are bleeding or at high risk of bleeding.

      All platelet components are leucodepleted and irradiated prior to release to the hospital. 

      Types of product available:

      Apheresis platelets

      Are collected from one donor and therefore limit the number of donor exposures to the patient. In patients who rely on platelet support e.g. severe aplastic anaemia, they may be selected when available to reduce the risk of alloimmunisation. 

      Apheresis platelets have the following characteristics:

      • Volume (mL)                              180 ± 11    (100 mL – 400 mL) 
      • Platelet count (109/unit)             280 ± 34

      Paediatric platelets

      One unit of apheresis platelets may be divided into four equal packs to create paediatric sized components. This will enable smaller patients requiring small but regular top ups to have exposure to less donor products and minimise product wastage. 

      Have the following characteristics:

      • Volume (mL)                              51 ± 2    (40 mL – 60mL) 
      • Platelet count (109/unit)             76 ± 10

      Pooled platelets:

      An adult dose of pooled platelets are obtained from a pool of buffy coats from four donors. These are pooled and re-suspended to create one unit of pooled platelets.

      Certain patient groups may require pooled platelets as the first choice. The ratio of plasma to platelets is less in pooled components than apheresis products and therefore the exposure to plasma is less. This becomes significant for those patient groups who have mild – moderate allergic reaction to apheresis platelets. 

      Pooled platelets have the following characteristics:

      • Volume (mL)                              326 ± 14    (>160) 
      • Platelet count (109/unit)             284 ± 40

      Compatibility

      The provision of ABO and Rh(D) identical platelet transfusion is ideal, but not always possible. If ABO compatible components are unavailable, patient age, weight, diagnosis and component availability (pooled vs apheresis) will influence the blood banks decision about what product to supply.

      An ABO incompatible platelet transfusions (group O platelets given to a group A patient) may be associated with clinically significant transfusion reactions, including a positive DAT, red cell haemolysis and even lower platelet survival in some patients. 

      Platelet components contain a small number of red cells that could be Rh incompatible with the recipient. Therefore RhD negative females with childbearing potential should receive platelet transfusions from RhD negative donors. If transfusion of RhD positive product to RhD negative recipient is unavoidable, consider giving Rhesus immunoglobulin (Discuss with haematologist-on-call)

      Indications

      Platelet count (x10^9/L)                            

                                                                             Clinical situation to trigger platelet transfusion 

      <10


      •Clinically stable paediatric patients receiving chemotherapy for leukaemia or post  haematopoietic stem cell transplantation (HSCT) 

      •Clinically stable patients with solid tumours (prophylactic)*

      •* Transfusions at higher levels may be required for bladder, brain or necrotic tumours •Critically ill patients with no bleeding


      <20


      •Chemotherapy, HSCT & risk factors (e.g. fever, sepsis, minor bleeding, mucositis, disseminated intravascular coagulopathy (DIC) without bleeding)

      •Critically ill patients with no bleeding and risk factors (e.g. sepsis, renal failure, medications)

      •Nasogastric tube insertion

      •Intramuscular injections e.g. Erwinia aspariginase

      •Insertion of a non-tunnelled central venous line


      <30


      •Lumbar puncture (LP) and on-going chemotherapy induced thrombocytopenia

      •Central nervous system (CNS) tumour and:

           - A VP shunt or Ommaya reservoir

           - Has a gross total resection and is receiving chemotherapy and/or radiation

           - Has residual tumour and is receiving chemotherapy and/or radiation


      <50


      •LP and new disease induced thrombocytopenia

      •Patient undergoing invasive procedure (including tunnelled central venous line insertion)

      •Moderate active bleeding (including bleeding associated with DIC)

      •CNS tumour and:

           - A past history of intracranial haemorrhage

           - Is receiving an anti- angiogenesis agent


      <75


      •Major haemorrhage due to trauma or significant post-operative bleeding (e.g. post cardiac surgery)


      <100


      •Patient undergoing high risk invasive procedure (e.g. neurosurgery/ophthalmology)

      •Extra-corporeal life support (ECLS) (lower platelets may be acceptable in stable patients)


      Platelet transfusion not appropriate                                                 


      •Stable patients with chronic, stable, severe thrombocytopenia due to alloimmunisation, ITP, TTP, aplastic anaemia or MDS should be observed without prophylactic platelet transfusions. These patients should receive platelet transfusions with clinically significant bleeding only.

      •Bone marrow aspirate and trephine biopsy

      •Intravenous cannula insertion



      ITP – immune thrombocytopenia, TTP – thrombotic thrombocytopenic purpura, MDS – myelodysplastic syndrome.  



      Platelet count (x10^9/L)

                                                                   

                                                                           Clinical situation to trigger platelet transfusion in neonates

      <25 - 30


      Stable term or preterm infant with asymptomatic thrombocytopenia and no bleeding


      30 - 50


      Sick preterm infant with thrombocytopenia


      <50


      Term or preterm infant with symptomatic thrombocytopenia and minor bleeding, coagulopathy or prior to surgery.


      <100


      Term or preterm infant with symptomatic thrombocytopenia and major bleeding or requiring major surgery (e.g. neurosurgery)




      Platelet Transfusion in patients undergoing stem cell transplantation

      Where possible, a platelet product compatible with both donor and recipient should be used. At RCH the platelet product choice for each transplant recipient will be specified by their transplant physician and will be listed on the Transplant Protocol

      Platelet transfusion in children with congenital platelet disorders

      Platelet transfusion in rare congenital platelet disorders such as Bernard-Soulier syndrome, Glanzmann's thrombasthenia, thrombocytopenia with absent radii (TAR), Wiskott-Aldrich syndrome, Fanconi anaemia, amegakaryocytic thrombocytopenia can provoke the development of multi-specific HLA or platelet specific antibodies and they should be used sparingly. They should be reserved for clinical bleeding or prior to invasive procedures with a high risk of bleeding.

      Donor exposure should be limited through the use of apheresis platelets and the risk of alloimmunisation reduced through the use of leukocyte reduced products.

      Platelet transfusion in immune thrombocytopenia

      Transfused platelets are rapidly destroyed and should be reserved for cases of life-threatening bleeding. 


      Dosing


      Platelet product    \    weight 

                       < 10 kg                    10 - 19 kg                20 - 29 kg        30 - 39 kg          > 40 kg


      Pooled platelets     (adult unit)

                       10ml/kg                     10ml/kg      10 ml/kg up to 1 unit          1 unit           1 unit


      Apheresis platelets # (adult unit)

                    5 to 10ml/kg                  5 to 10ml/kg   5 to 10 ml/kg up to 1 unit          1 unit           1 unit


      Paediatric apheresis platelets # (pedipak)

          5 - 10 ml/kg or 1 pedipak         5 - 10 ml/kg or 2 pedipaks           3  - 4 pedipaks       4 pedipaks        4 pedipaks


      # can be used to reduce donor exposure in chronically transfused patients

      If a pedipak is not available, and platelet transfusion is required, transfuse using an adult unit at a dose of 5-10 ml/kg over 2-3 hours.


      Special Products

      Phenotype specific for patients with fetomaternal alloimmunisation (FMAIT)

      The infant or fetus with confirmed or suspected alloimmune thrombocytopenia should be transfused platelets which are negative for the implicated alloantigen. Platelets negative for the HPA-1a antigen (implicated in 85% of cases of FMAIT in Caucasian populations) are often available from ARCBS but may be sourced from interstate. Contact the haematologist-on-call for advice regarding platelet support in this clinical situation.

      HLA matched for immunised refractory patients:

      When patients fail to achieve a significant and sustained rise in the platelet count following platelet transfusion (platelet increment) they are said to be 'refractory'. There are clinical and immunological causes of platelet refractoriness. Clinical causes include fever, sepsis, bleeding, DIC and some drugs. In these situations, patients may respond to more frequent platelet transfusions or higher doses of platelets. Patients undergoing stem cell transplantation, who are multiply transfused, or who have had prior pregnancy may become refractory to platelet transfusion due to the development of multispecific HLA or platelet-specific antibodies. These patients may require platelet support from HLA (Human Leucocyte Antigen) or HPA (Human Platelet Antigen) matched donors. 

      If HLA or HPA matched apheresis platelets are required, please contact the RCH Blood Bank, ph 55829.

      IgA deficient:

      IgA deficient components may be used in patients who have developed an anti-IgA antibody and who also have recurrent, severe allergic reactions. The FFP is obtained from donors who have known low titre IgA/IgA deficiency.

      Platelet administration

      The patient should be ready for transfusion prior to picking up platelets from the blood bank. e.g. appropriate IV access and medical order for transfusion.

      A Blood Bank Release form is required for all blood products to be picked up from the blood bank, refer to issue of blood products from the blood bank.

      Complete positive patient and blood product identification prior to transfusion of platelets as per RCH Blood Transfusion - Fresh Blood Products Procedure.

      Care and monitoring of transfused patients, refer to Blood Administration

      Administer via a volumetric pump or syringe driver to ensure accurate volume delivered.

      Standard 170-200 micron filter either in-line or on transfer to syringe.

      Use a new blood administration filter (170 - 200 micron) when administering platelets.

      Do not transfuse though the same blood administration filter after red blood cell transfusion as some platelets may get caught in fibrin strands/debris caught in filter (Exception: critical bleeding event, can continue to use the same blood administration filter unless flow is impeded by debris caught in the filter).

      Adverse effects of platelet transfusion

      See section on adverse effects of transfusion.

      Platelet products are collected from volunteer donors screened with standard screening tests and have the same risks of infectious disease transmission as red cell products.