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Products / Services
Product Profile : Platelets
Platelet transfusions are required in a number of conditions
to control bleeding episodes. The decision to transfuse
should be based on a combination of clinical and laboratory
findings rather than on empirical platelet levels. Response
to platelet transfusions should be judged on clinical improvement,
normalisation of bleeding time, and relative increase in
circulating platelet count. Significant increases may not
occur in the actively bleeding patient due to rapid utilisation.
Indications for Platelet Transfusions
- Bleeding due to thrombocytopenia, which
is the result of defective platelet production (aplastic
anaemia or leukaemia).
- Defective function (congenital platelet
disorders).
- Increased consumption (disseminated intravascular
coagulation).
- Dilutional effect as in massive transfusion.
Thromboctytopenia and
bleeding
| PLATELET COUNT |
RISK OF BLEEDING
|
| < 5 x 109/l |
Life threatening bleeding is a strong
possibility |
| 5-20 x 109/l |
Increased likelihood of spontaneous bleeding,
particularly intracranial haemorrhage |
| 20-50 x 109 /l |
Increased likelihood of bleeding with
trauma, surgical
procedures and specific lesions such as
gastric ulcers |
| > 50 x 109/l |
Bleeding rarely occurs, even in major
surgery.
For surgery to the eye or brain a platelet level of
100 x 109/l
is recommended |
Clinical evidence of Thrombocytopenia
or Thrombopathy include:
- Diffuse oozing from surgical incision.
- Oozing from venepuncture sites.
- Scattered petechiae.
- Ecchymoses in areas not associated with
trauma or incisions.
- Mucocutaneous bleeding.
- Retinal bleeding.
Platelet Products
Random donor platelets
- These platelet concentrates are prepared
from whole blood within 8 hours of collection. The concentrates
may be stored for 5 days in special satellite bags that
allow for gaseous exchange at 22 °C with continuous
agitation. Each single donor unit contains approximately
60-80 x 109 platelets in 50 ml of citrated plasma.
- To transfuse sufficient platelets for a
therapeutic dose several of the individual units are pooled.
In general, random donor platelets are recommended for
acute disorders such as acute disseminated intravascular
coagulation.
Apheresis single donor platelet
concentrate
- This is a unit of platelets from a single
donor, prepared by using standardised protocols on a blood
cell separator. Each unit contains at least 300 x 109
platelets in 300 ml of citrated plasma. Depending on the
system used the product has a shelf life of 24 hours (open
system) to 5 days (closed system). The product has fewer
than 5 x 106 leucocytes in total, and is considered leucocyte
depleted.
- Apheresis products are particularly recommended
in patients on long term platelet support (e.g. bone marrow
transplant) to minimise exposure to alloantigens. The
risk of exposure to latent donor infections is also reduced,
and is therefore probably preferable to random donor platelets.
However, they are more costly and time consuming to produce.
Improved method of pooling random donor
platelet concentrates
Previously, Random Donor Platelets were stored
individually at our Blood Banks and pooled manually into
a single Transfer Pack on demand, using aseptic technique
under laminar Flow. The resultant pooled product typically
provided approximately 3x10 " platelets from 5-6 Random
Donor Platelet concentrates in approximately 300 ml Plasma.
The improved product is obtained by pooling
5-6 units of Random Donor, Buffy Coat (BC) Platelet Concentrates
immediately after preparation, using a sterile, multi-armed
pooling bag and an electronic sterile tube welding device.
Preparation in an entirely closed, sterile
system and the mechanism of the new pooling bag, enable
us to provide a product that will typically contain 3 x10"
platelets from 5 Random Donor BC Platelet Concentrates in
approximately 250 ml plasma.
Benefits of the new, Pooled Platelet product
include decreased risk of bacterial contamination, reduced
exposure of patients to random donors and ready availability
as the product is pre-pooled.
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