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What happens to donated blood? Patients need blood, maybe due to blood loss from accidents, diseases that require blood transfusion, or even organ transplants. We answer the call and volunteer to donate blood, and by doing this, we save lives. However, have you ever wondered what happens to donated blood after it is drawn from a vein in your arm?
The process from donation to transfusion is swift and carefully monitored. It involves collecting, testing, processing, storing, and distributing to hospitals. Each step ensures that the blood is safe and ready to help those in need. In this guide, we will discuss the whole process from donation to transfusion.
What is blood donation?
Blood donation is the process of voluntarily providing blood for transfusion to save lives. Donation can be whole blood or specific components like plasma or platelets. People might need blood for various reasons, such as accident victims who have had significant blood loss, anemic patients undergoing major surgeries, cancer patients, and women in childbirth.
Types of blood donation
There are several types of blood donation that help meet certain medical needs.
- Whole blood donation
This is the most common type of blood donation. An individual donates about half a litre of whole blood. It is then separated into red cells, plasma, and platelets.
- Apheresis
In Apheresis, the donor is directed into a machine that collects blood and separates it into different components. After separation and taking the required components, the machine returns the remaining blood to the donor
Double red cell donation is the collection of concentrated red blood cells. Red blood cells are responsible for circulating oxygen to organs and tissues. It is typically given to trauma victims, surgical patients, or individuals with chronic anemia requiring transfusion.
Plasmapheresis (plasma donation) is the collection of plasma from blood. Plasma contains clotting factors and is used to treat conditions like liver disease, severe bleeding, and clotting disorders, especially in emergency or surgical settings, to accelerate the process of clotting and prevent excessive bleeding.
Plateletpheresis (platelet donation) is the collection of platelets from whole blood. Platelets help to stop bleeding by forming clots in the blood vessels. Plates are mainly used for cancer patients undergoing chemotherapy, bone marrow disorders, and individuals with severely low platelet counts..
What happens to donated blood? Step-by-step process
After a successful donation, the blood is;
Taken for tests
After donation, the blood is safely packed and sent to a processing centre where various tests are carried out. This is because people who need the blood are already sick and vulnerable to getting infected with viruses, bacteria, or other infections. Therefore, the blood needs to be screened to protect them and ensure that it is safe for donation.
What is tested?
- Blood type
When someone donates blood, their blood type needs to be known so that they get blood that is compatible with theirs. Failure to do so can lead to various risks that can be life-threatening, such as red blood cell agglutination.
Two systems make up blood type:
- ABO (Blood types A, B, AB, and O)
- RH Type or group “rhesus factor” (positive or negative)
| Blood type | Compatible blood types |
| O- | O- |
| O+ | O-, O+ |
| B- | B-, O- |
| B+ | B+, B-,O+, O- |
| A- | A-, O- |
| A+ | A+, A-, O+, O- |
| AB- | AB-, A-, B-, O- |
| AB+ | AB+, AB-, A+, A-, B+, B-, O+, O |
O- red blood cells can be given to anyone and are often used in emergencies
AB plasma, positive or negative, can be given to anyone
- Red cell antibodies
All donations are then tested for red cell antibodies. These antibodies are proteins that react with red blood cells. They might be harmful to the recipient and are important to identify for compatibility during transfusion.
- Infectious diseases
Before any transfusion, the blood must be screened for several infectious diseases, including HIV, Hepatitis B and C, syphilis, HTLV, and sometimes malaria or Chagas disease, depending on the region.
Some other tests that are carried out are for testing syphilis, CMV, and malaria, if the donor comes from a place prone to malaria.
If the test turns positive, the donor is notified and provided with guidance and support. The infected blood is no longer used.
Processing
After the tests come back clean, the blood is centrifuged to separate it into red blood cells, plasma, and a buffy coat of white blood cells and platelets.
- Red blood cells
To avoid transfusion-related reactions, the white cells are removed through filtration. This process is called leucodepletion
They can also be washed to remove excess plasma proteins before they go to a patient
Sometimes, the blood is irradiated, which is the process of exposing the blood to radiation. This helps prevent transfusion-associated graft-versus-host disease (TA-GvHD), which happens when the transfused white blood cells see the patient as foreign and attack the patient’s cells. It can lead to death.
The process of irradiation doesn’t remove the white cells but prevents them from multiplying, to stop the disease.
They are stored at 1◦c to 6◦c in special refrigerators. Depending on the preservative solution used, they can only be stored for 42 days.
- Plasma
Plasma makes up about 55% of the total blood volume in the human body. Fresh frozen plasma can be used to replace clotting factors or used in different treatments. It is stored at -18◦c or colder and can be stored up to 1 year.
- Immunoglobulins enhance immune response to disease and treat autoimmunity
- Clotting factors used in the treatment of hemophilia and bleeding disorders
- Albumin is used to supplement low albumin levels.
- Platelets
Like red blood cells, platelets are filtered to remove white blood cells. They can only be stored for 7 days at 20◦c to 24◦c with continuous gentle agitation.
Transportation to the hospitals
After the blood is separated, it is placed in a plasma extractor that separates red cells, plasma, and platelets into different bags after centrifugation. The components are then sent to hospitals or clinics, where it is matched and transfused to patients in need
