In this section
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.
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:
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
Have the following characteristics:
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
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
Pooled platelets have the following characteristics:
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.
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.
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)
Platelet count (x10^9/L)
Clinical situation to trigger platelet transfusion
paediatric patients receiving chemotherapy for leukaemia or post haematopoietic stem cell transplantation (HSCT)
stable patients with solid tumours (prophylactic)*
Transfusions at higher levels may be required for bladder, brain or necrotic
ill patients with no bleeding
•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
•Insertion of a non-tunnelled central
•Lumbar puncture (LP) and on-going
chemotherapy induced thrombocytopenia
•Central nervous system (CNS) tumour
VP shunt or Ommaya reservoir
a gross total resection
and is receiving chemotherapy and/or radiation
residual tumour and is receiving chemotherapy and/or
•LP and new disease induced
•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
receiving an anti- angiogenesis agent
•Major haemorrhage due to trauma or
significant post-operative bleeding (e.g. post cardiac surgery)
•Patient undergoing high risk invasive
procedure (e.g. neurosurgery/ophthalmology)
•Extra-corporeal life support (ECLS)
(lower platelets may be acceptable in stable patients)
•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
•Bone marrow aspirate and trephine
•Intravenous cannula insertion
ITP – immune thrombocytopenia, TTP –
thrombotic thrombocytopenic purpura, MDS – myelodysplastic syndrome.
Clinical situation to trigger platelet transfusion in neonates
term or preterm infant with asymptomatic thrombocytopenia and no bleeding
preterm infant with thrombocytopenia
or preterm infant with symptomatic thrombocytopenia and minor bleeding,
coagulopathy or prior to surgery.
or preterm infant with symptomatic thrombocytopenia and major bleeding or
requiring major surgery (e.g. neurosurgery)
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 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.
Transfused platelets are rapidly destroyed and
should be reserved for cases of life-threatening bleeding.
Platelet product \ weight
Apheresis platelets # (adult unit)
Paediatric apheresis platelets # (pedipak)
# 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.
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
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.
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.
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).
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.