What is it about ?
A blood transfusion is the use of blood from a donor to treat a ‘recipient’. Blood is not transfused directly after donation. It is first separated into usable components, which may be useful to different people, and then it is subjected to extensive testing.
Usable components
The following components are extracted from the blood:
- red blood cells (erythrocytes), which supply the lungs and other tissues in the body with oxygen. They are transfused in the following cases: anemia chronic with symptoms, elective operations, heavy and sudden bleeding after an accident, during an operation, during childbirth, etc.
- fresh frozen plasma, which is transfused in cases of bleeding characterized by a lack of clotting factors.
- platelets (thrombocytes) are mainly transfused in the event of blood diseases characterized by a lack of platelets.
Blood tests
The donated blood undergoes a number of tests:
- blood group check: the blood group is determined on the basis of antigens (special proteins that are stuck to the surface of red blood cells). There are four different blood groups: A (A antigen), B (B antigen), AB (A and B antigens) or O (no antigens). To each group is added the rhesus factor (positive or negative).
- identification of antibodies against certain diseases;
- check that the donor’s blood matches that of the recipient (depending on the blood group).
What can you do ?
A blood transfusion can save a life. It is therefore essential that the blood reserves be sufficient. You can help by donating blood through the Red Cross.
What can your doctor do?
Blood transfusions are usually done in the hospital and, in rare cases, at the home of the person who needs them, but only when the previous transfusions have gone without problems and the attending physician assumes full responsibility. of the procedure.
A blood transfusion must follow a well-defined procedure. This is because the administration of blood from the wrong group or the wrong rhesus factor can trigger life-threatening reactions. The hospital therefore follows strict protocols before transfusing the donated blood.
If a transfusion reaction or transfusion error is suspected, the transfusion is immediately stopped and a procedure is started to treat the person correctly and avoid other possible mistakes.
What are the potential complications ?
Side effects
Any blood transfusion, even if done correctly, can cause side effects. The most common are fever and a mild allergic reaction with itching and rash, which can be relieved with medication. In exceptional cases, a severe allergic reaction may occur characterized by a shortness of breath, a rash all over the body, low blood pressure, nausea and an loss of consciousness. This situation can be fatal. In this case, additional measures should be taken during a future transfusion. One of these measures may be, for example, to use only ‘deplasmatized’ (or ‘washed’) blood cells, such as red blood cells and platelets, largely getting rid of the plasma.
Hemolysis and TRALI
If you give blood from the wrong group, the recipient’s antibodies will break down the red blood cells (acute hemolysis). This problem is manifested by the following symptoms: fever, restlessness, pain in the chest and lower back, low blood pressure, respiratory distress, decrease or absence of urination, and reddish-brown urine. The severity of symptoms depends on the number of transfusions and the amount of antibodies. Acute hemolysis is treated by administration of fluid.
Sometimes the donor’s antibodies form or are activated after the transfusion and only start to break down new red blood cells after a while (delayed hemolysis). This hemolysis usually occurs after one to four weeks and is manifested by jaundice, a anemia or abnormal coloring of the urine.
Very rarely, a blood transfusion can cause ‘transfusion-related acute lung injury’ (TRALI). We do not know how to explain the occurrence of this syndrome. Sudden respiratory distress occurs within 6 hours of the transfusion. An x-ray of the lungs shows abnormalities in both lungs. If not treated quickly, TRALI can be fatal.
Infections
Bacteria and viruses can be transmitted by blood transfusion and cause infection. However, this has become very rare thanks to the strict controls on donated blood. If there is still bacteria in the blood, it usually comes from the donor’s skin. A bacterial infection due to a blood transfusion manifests itself, during or immediately after the transfusion, with high fever, low blood pressure and nausea. Donated blood can, in very rare cases, contain a virus.