In this section
A variety of platelet products are produced by ARCBS in
These platelets are collected from a single donor via
apheresis and are suspended in plasma.
Volume: 40-60mL (actual volume is specified on the label)
Platelet Count: >60 x 109/unit
White Cell Count: < 1.0 x 106/unitThese platelets are suitable for neonatal
and paediatric use (see table for appropriate dose)
An adult dose of platelets derived from whole blood is obtained from a pool of buffy coats from four ABO identical donors and is resuspended in a nutrient additive solution to produce a pooled platelet component
Volume: >160mL (actual volume is specified on the label)
Platelet Count: >240 x 109/pool
White Cell Count: < 1.0 x 106/poolThese platelets are suitable for adults
and paediatric patients > 40kg.
Platelet Apheresis Leucocyte Depleted
These platelets are collected from a single donor via
apheresis and are suspended in plasma.
Volume: >100 (actual volume is specified on the label)
Platelet Count: >240 x 109/unit
White Cell Count: < 1.0 x 106/unitThese platelets are suitable for adults
and paediatric patients > 40kg.
All platelets produced in Victoria are;
In times of product shortage, platelets may be sourced from
interstate and may not be leucocyte depleted. It is therefore
imperative to read the label on
Platelets are stored at 20-240C on a platelet
agitator for a period of 5 days from collection. (Do not
Platelet expiry is at midnight on the date specified on the
Pooled platelets (Adult unit)
5 - 10 ml/kg
1 unit or 10 ml\kg
Whichever is less
Apheresis platelets (Adult unit)
1 unit or 10 ml/kg
Paediatric apheresis platelets (pedipak)
1 pedipak or 5 - 10 ml/kg
2 pedipaks or 5 - 10 ml/kg
3 pedipaks or 5 - 10 ml/kg
4 pedipaks or 5 - 10 ml/kg
Patient's ABO Group
B or A
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.
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
If HLA or HPA matched apheresis platelets are required, please contact the RCH Blood Bank, ph 55829.
The patient should be ready for transfusion prior to picking up
platelets from the blood bank. eg appropriate IV access, written
order for transfusion. A Blood Bank Release Order is required for
all products to be picked up from the blood bank, refer to issue of
blood products from the blood bank.
Administer via Standard 170-200 micron filter either in-line or
on transfer to syringe.
Suitable products include:
Use a fresh administration set for platelets. Do not transfuse
though a standard filter straight after red cells as platelets will
get caught up in fibrin strands /debris etc.
All platelet products issued from Red Cross Victoria
are leucocyte depleted as indicated on the product label.
As for all blood products adhere to pre-transfusion check and
care and monitoring of transfused patients, refer to Blood
Rate: Platelet transfusion must be completed within 4 hours of
spiking pack. Occasionally platelets are given over 30 minutes, but
this may contribute to an increased risk of some reactions
(fever/chill) and fluid overload.
In patients receiving multiple other fluids etc give at a rate
of 3ml/kg/hr over 2-3 hours.
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.
Some adverse reactions may occur more commonly with platelet
Critically ill patients (limited evidence, suggested thresholds. NB: higher transfusion triggers may be acceptable in certain circumstances)
Active bleeding - Platelet count <50 x 109/L
Neonatal thrombocytopenia - <30 - 50 x 109/L (See table below for further information)
Children with leukaemia are the largest single group of patients
receiving platelet transfusions. Platelet transfusion is used
therapeutically in patients with bleeding and significant
Prophylactic platelet transfusion is not routinely used during
induction therapy for Acute Lymphoblastic Leukaemia or for solid
tumours (with the exception of brain tumours) unless patients are
symptomatic, there is active bleeding, an invasive procedure or
additional risks such as fever.
Prophylactic platelet transfusion during induction chemotherapy
for Acute Myeloid Leukaemia using a threshold of 10 x
109/L and during the pre engraftment phase of stem cell
transplantation using a threshold of 20 x 109/L is
A number of studies show that bleeding is more likely to arise
in disease-induced than therapy-induced thrombocytopenia, and the
presence of additional risk factors such as sepsis, drugs that
impair platelet function, abnormal haemostasis or invasive
procedures increase the risk of bleeding and a higher threshold is
recommended. A platelet count above 30-50 x 109/L is
generally acceptable for lumbar puncture, above 50 x
109/Lfor minor surgery and above 80-100 x
109/L for major surgery such as neurosurgery.
In the absence of evidence-based guidelines for children, the
following clinical circumstances represent acceptable indications
for platelet transfusion in stem cell recipients.
Prophylactic platelet transfusion during the pre engraftment
phase of stem cell transplantation using a threshold of 20 x
A higher threshold may be used in the presence of bleeding,
severe mucositis, coagulopathy or concurrent anticoagulation.
ABO incompatibility between the patient and stem cell donor may
be major, minor or both. In major incompatibility, the recipient
has antibodies to the stem cell donor's red cells (eg group A donor
and group O recipient); in minor incompatibility the stem cell
preparation from the donor has antibodies to recipient red cells
(eg anti-A in group O donor and group A recipient); in both major
and minor incompatibility, the recipients plasma contains
antibodies to the donor's cells and the donor plasma contains
antibodies to the recipient's cells (eg group B recipient and group
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 the Transplant
There are several inherited platelet disorders that occasionally
require platelet transfusions. Platelet transfusion has been shown
to be of benefit in Bernard-Soulier syndrome and Glanzmann's
thrombasthenia to cover surgery or a bleeding episode. Platelet
transfusion can provoke the development of multi-specific HLA or
platelet specific antibodies and they should be used sparingly.
Donor exposure should be limited through the use of apheresis
platelets and the risk of alloimmunisation reduced through the use
of leukocyte reduced products.
There are many rare causes of defects in platelet production
such as thrombocytopenia with absent radii (TAR), Wiskott-Aldrich
syndrome, Fanconi anaemia, amegakaryocytic thrombocytopenia.
Platelet transfusion should be used sparingly and reserved for
clinical bleeding or invasive procedures since many patients with
these conditions will require stem cell transplantation.
Transfused platelets are rapidly destroyed and should be
reserved for cases of life-threatening bleeding.
Platelet transfusion may be warranted in the patient with
unexplained excessive bleeding undergoing cardiopulmonary bypass.
Patients undergoing ECMO are usually transfused to maintain a
platelet count > 100 x 109/L.
Asymptomatic thrombocytopenia- Stable term or preterm infant consider if platelet count
< 20-30 x 109/L
- Sick term or preterm infant consider if platelet count less than
30-50 x 109/L
Symptomatic thrombocytopenia in any neonate- Major organ bleeding and platelet count < 100 x
- Minor bleeding and platelet count < 50 x 109/L
Thrombocytopenia and invasive procedures
- Surgery: consider if platelet count < 50 x
- Exchange transfusion: consider if platelet count < 50 x
109/LThrombocytopenia and DIC
- Consider if platelet count < 50 x 109/L
Thrombocytopenia is the most common haemostatic abnormality in
sick newborn infants. The immature coagulation system in neonates
contributes to an increased bleeding risk. Platelet transfusions
are indicated for the support of selected neonates with clinically
significant quantitative or qualitative platelet disorders.
Consideration should be given to the cause and natural history of
the thrombocytopenia, as this may alter the type of platelet
In the only reported randomised controlled study of platelet
transfusion in preterm infants, Andrew et. al. found no benefit
(defined as the reduction of significant haemorrhage) in babies
where moderate thrombocytopenia (50-150 x 109/L) was
prevented by platelet transfusion compared to control babies.
Guidelines for platelet transfusion in the neonate acknowledge
the lack of evidence on which to make recommendations and aim for a
safe approach. Experience from allo-immune thrombocytopenia
indicates that in a well term neonate, the risk of significant
haemorrhage as a result of thrombocytopenia is unlikely at counts
above 30 x 109/L, however for preterm infants, despite
the lack of evidence, a higher threshold of 50 x 109/L
FMAIT is a serious disease capable of causing significant
morbidity or mortality from haemorrhage in-utero or during the
perinatal period. Intracerebral haemorrhage (ICH) secondary to
severe thrombocytopenia has been reported as early as 18 weeks
gestation. The level of thrombocytopenia which places the fetus at
risk is not known, but ICH has rarely been reported in neonates
with platelet counts greater than 30 x 109/L. Weekly or
fortnightly platelet transfusion given in-utero have been used to
reduce the risk of ICH, however others recommend maternal IVIG to
raise the fetal platelet count. Appropriate antigen-negative
platelets should be available to be given to a fetus undergoing any
invasive procedure such as cordocentesis.
For the neonate with FMAIT, platelet transfusion is the
treatment of choice and should be given to normalise the platelet
count in an infant with ICH or to treat severe throbmobocytopaenia
in infants without ICH. Platelets used for neonates with FMAIT
should be negative for the implicated platelet-specific antigen.
Maternal platelets which have been plasma-reduced and irradiated
are sometimes used.
Neonates born with CMV infection, rubella, toxoplasmosis,
syphilis or herpes simplex may have suppression of thrombopoiesis
and/or splenomegaly with shortened platelet survival. Mild to
moderate thrombocytopenia may be present. This usually does not
require platelet support.
Neonatal thrombocytopenia may be associated with past or current
maternal ITP. The majority of infants are only mildly affected and
the thrombocytopenia resolves spontaneously Severe thrombocytopenia
is reported to occur in a approximately 4% of neonates and the
incidence of ICH is extremely low. Intravenous immunoglobulin and
steroids are the treatments of choice where the thrombocytopenia is
severe or bleeding is present.
Intrauterine transfusion (IUT) of platelets is used to correct
fetal thrombocytopenia caused by platelet alloimmunisation. IUT of
platelets is used to correct fetal thrombocytopenia and reduce the
risk of cord haemorrhage during fetal blood sampling procedures and
is used as therapy to prevent intracerebral or other major
haemorrhage in some cases of alloimmune thrombocytopenia. IUT is
used to maintain an acceptable fetal platelet count while enabling
the pregnancy to advance to a gestational age where the risks of
prematurity are less than the risks of ongoing pregnancy, and with
as few invasive procedures as possible. IUT is associated with a
risk of fetal loss estimated at approximately 1%.
Thrombocytopenia is not uncommon during pregnancy, and the
majority of women with mild to moderate thrombocytopenia do not
require platelet transfusion. Platelet transfusion is virtually
never required for gestational thrombocytopenia, and rarely
required in ITP. The most common clinical situations requiring
platelet support in pregnancy include; thrombocytopenia occurring
in the setting of major post partum haemorrhage, DIC or placental
abruption, or in the setting of severe pre-eclampsia or HELLP
(Haemolysis, Elevated liver enzymes and Low Platelets)
Pregnant women who are CMV negative or CMV status unknown should
receive CMV seronegative platelets