What are blood products (blood components) and how are they used?

Donated blood (whole blood) is divided into several products:

  • Packed red blood cells – the red blood cells carry oxygen from the lungs to the body. They may be given for rapid bleeding or anemia (low red blood cell numbers).
  • Plasma is the fluid portion of blood that is separated from the red blood cells and frozen for later use. Plasma contains coagulation factors that help control (stop) bleeding.
  • Platelets help stop bleeding by combining with thrombin to form a clot at the bleeding site.
  • White blood cells are rarely transfused, but may be given to patients with infections and very low white blood cell counts.

Why would my child need a blood transfusion?

  • to increase the number of red blood cells that carry oxygen in the blood
  • to replace blood lost from an injury, during surgery, or due to a medical condition
  • to replace needed blood components:
    • plasma (provides coagulation factors)
    • platelets
  • to control bleeding

How will I know if my child needs a transfusion?

The doctor will discuss the need for transfusion with you before it is given. This is a chance to discuss your questions and concerns with the doctor before you agree to a blood transfusion for your child.
However, in an emergency, the doctor may have to decide whether to transfuse before talking to you.

What are the risks of transfusion?

Blood for transfusion is given by healthy volunteers. Every donation is tested for the following diseases, which can be transmitted by a blood product:

  • hepatitis B and C
  • human immunodeficiency virus types 1 and 2 (HIV, the AIDS virus)
  • human lymphotrophic virus, types I and II
  • syphilis

Today’s blood supply is very safe because of improved screening and testing; however, all blood transfusions have a small chance of causing problems.

Risk for each unit of blood

    • rash, hives, itching: 1 in 33 to 100
    • fever: 1 in 17 to 200 (red cells) 1 in 3 to 100 (platelets)
    • hemolysis (breakdown of red blood cells): 1 in 38,000 to 70,000
    • hepatitis C: 1 in 1,600,000
    • hepatitis B: 1 in 180,00 (hepatitis B can be prevented by getting the hepatitis B vaccine)
    • HIV (the AIDS virus): 1 in 1,900,000
    • bacterial contamination (infection):
      • 1 in 2,500 to 13,400 platelet transfusions
      • 1 in 38,565 red blood cell transfusions

How do these risks compare to other risks in life?

Estimated risk of death in a year per person in the United States:

      • home accident: 1 in 1,100
      • influenza (the “flu”): 1 in 5,000

Are there alternatives to a blood transfusion?

There are currently no substitutes for red blood cells, platelets, and most plasma proteins. Some people may use autologous blood donation (donate blood for themselves before surgery), but this is limited to certain planned operations and depends on the size and age of the child. Some families prefer to use directed donations (have family or close friends provide the blood), but this option has not been shown to decrease the transfusion risks.


This sheet is not specific to your child, but provides general information. If you have questions, please ask the doctor.