Blood Transfusion Process
Once the donor has donated the blood it is processed into a number of products suitable for use in the clinical care of patients.
First, the blood is filtered to remove the white blood cells from it. White blood cells are important to prevent and fight infections, but they do not work when transfused as part of an ordinary blood donation.
Next, we separate out the red blood cells, and add a special nutrient fluid to them to allow us to preserve them for up to five weeks.
Red Cell Uses
In the body red blood cells are essential to carry oxygen to all cells in all your tissues and organs. Red cell depletion occurs for any of the following scenarios:
- Red cells are lost from bleeding after injury or during surgery.
- The body loses the capacity to make enough of its own red cells.
- A genetic condition prevents proper red cell formation by the body.
- The body loses the ability to produce enough of its own red blood cells when undergoing chemotherapy for cancer.
As part of the blood transfusion process we separate out the platelets. These are very small cells that are essential for blood clotting. Platelets are used in the following scenarios:
- Patients who receive chemotherapy for cancer may need platelet transfusions to help their blood clot effectively.
- Heart surgery patients and victims of serious trauma can need platelet transfusions too.
Platelets have a short shelf life of five days. So keeping the supply going is a constant challenge. Around 22,000 doses are used in Irish hospitals per annum. Learn about Giving Platelets and what happens at the platelet clinic.
Blood Plasma Uses
The third component of each blood donation is the plasma. This is the fluid in which the cells are suspended in the bloodstream. You have about three litres of it circulating through your blood vessels. It has proteins necessary for immunity and for blood clotting. Plasma can be stored frozen. Plasma is used in the following circumstances:
- Replace proteins where they are lost due to a large blood loss from trauma and during surgery.
- Plasma is used to make purified concentrates. For example patients often receive treatment with immunoglobulin concentrates or albumin made from plasma.
(excerpt : blood transfusion service website)