In a blood transfusion, donated blood is added to your own blood. A blood transfusion may also be done to supplement various components of your blood with donated blood products. Sometimes a blood transfusion is done with blood that you've donated ahead of time before you undergo surgery.
During a typical blood transfusion, whole blood or certain parts of blood are infused through an intravenous (IV) line and needle that's placed in one of the veins in your arm. A blood transfusion usually takes one to two hours, though in an emergency it can be done much faster.
A blood transfusion boosts blood levels that are low, either because your body isn't making enough or because blood has been lost during surgery, injury or disease.
Why it's done
There are many reasons people receive blood transfusions, including surgery, injury, disease and illness. Blood has several components, including red cells, white cells, plasma and platelets. You'll receive a transfusion that provides the part or parts of blood that will be most helpful for you. Whole blood means the blood contains all its parts, but whole blood is rarely used for transfusion.
Researchers are working on ways to develop an artificial blood, but so far there's no universally accepted replacement for human blood.
Surgery, injury or anemia
Infection, liver failure or severe burns
Severe liver malfunction
Blood transfusion is a common procedure that usually goes without complications. But there are some risks. Some transfusion reactions happen during the transfusion, while others may take several weeks to develop or become noticeable.
Allergic reaction and hives
Acute immune hemolytic reaction
Delayed hemolytic reaction
How you prepare
Your blood will be tested before a transfusion to determine whether your blood type is A, B, AB or O and whether your blood is Rh positive or Rh negative. Donated blood that is compatible with your blood type will be selected for the transfusion.
Your doctor may prescribe a medication for you to take before the transfusion to reduce the chances that you'll have an allergic reaction. Usually you don't need to modify your activity levels or diet before a transfusion.
If you've had a reaction to prior blood transfusions, be sure to tell your doctor.
What you can expect
Blood transfusions are usually done in a hospital, outpatient clinic or doctor's office. A blood transfusion typically takes one or two hours, depending on which parts of the blood you receive and how much blood you need. You're usually seated or lying down for the procedure.
During the procedure
If you develop a fever, shortness of breath, pain at the site of transfusion or chills, or if you feel itchy or uneasy, you should tell your nurse immediately.
After the procedure
You may need further blood testing to see how your body is responding to the donor blood and to check if your blood levels have reached an appropriate level.
For example, if before the transfusion you were anemic, meaning you had low levels of red blood cells, your doctor will check to see how much the transfusion raised your red blood cell count.
Or, if you've had low platelets because of chemotherapy drugs, your doctor may test your blood to see whether the transfusion sufficiently boosted your platelet count. Some conditions require repeated blood transfusions.
Last Updated: 2010-01-21
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