Blood Transfusion

A blood transfusion involves receiving donated blood or blood products intravenously.  Blood transfusions are most commonly used in situations where the patient has suffered significant blood loss, and to treat severe anemia or blood disorders.

The average adult has about 5 liters of blood and transfusion is deemed necessary if more than 1.5 liters have been lost.  Below that volume, lost blood can temporarily be replaced by salt solution while the body replenishes its blood supply over the next few weeks.

Function; Why it is Recommended

Each unit of blood usually takes 2-3 hours to transfer into the patient's bloodstream.  A unit of plasma or platelets generally takes 30-60 minutes.

Donated blood is often separated into its components:

• Red blood cells: These transport oxygen to where it is needed, and are used to treat anemia
• White blood cells: Help the body to fight infection
• Platelets: These help stop excessive bleeding
• Plasma: This makes up the bulk of the blood volume and contains a large variety of nutrients

Blood transfusions are used in a variety of situations, including:

• Replacing lost blood after high-blood-loss surgery, childbirth, or a major accident
• Treating inherited blood disorders

• Red Blood Cell Transfusion for:

  • Conditions that hamper the production of normal blood cells (e.g. sickle cell anemia, thalassemia)
  • Conditions that cause excess and/or premature destruction of blood cells (e.g. malaria, drug side-effects, toxins such as alcohol or lead, and certain autoimmune disorders)
  • Disorders that prevent the body from producing a sufficient amount of blood, for example anemia due to deficiency of iron, vitamin B or folate, and certain types of cancer (e.g. AML, lymphoma)
  • Treating anemia that has not responded to other treatments

• Platelet Transfusion to treat low platelet levels (thrombocytopenia) caused by:

  • Severe infection
  • Sepsis
  • Liver cirrhosis
  • Chemotherapy
  • Bone marrow transplant
  • Cancer (e.g. lymphoma, leukemia)

• Plasma Transfusion to help with blood clotting

  • After severe bleeding (trauma, surgery, childbirth)
  • Conditions that impair production of clotting proteins (e.g. liver disease)
• White Blood Cell (Granulocyte) Transfusion for infections that don't respond to antibiotics after chemotherapy or a bone marrow transplant

Counter-Indicators and Warnings

Donors should be carefully selected, and the donated blood should be carefully screened for blood group, disease and pathogens.  Unfortunately this screening is not so strict in some countries, so blood transfusion carries a higher risk of acquiring diseases such as hepatitis B or C, HIV/AIDS, or syphilis.