A   B   C    D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z

Penn State Pathology and Laboratory Medicine

Blood Transfusion

What is it?

Blood transfusion is the process of transferring blood or a blood component from one person, the donor, to another person, the recipient.

Who needs this procedure?

Blood transfusions are given to increase the blood's ability to carry oxygen, to restore the body's blood volume when there has been a great blood loss, to improve the blood's clotting ability, and to improve a recipient's immunity to infection. Depending upon the recipient's needs, a doctor may order a whole blood transfusion, or a blood component. Blood components include red blood cells, white blood cells, platelets, immunoglobulins, or fresh frozen plasma, which is the liquid part of the blood. Whole blood is usually used with patients who have lost a lot of blood, and to make sure the body's tissues are receiving enough oxygen. Red blood cells restore the blood's ability to carry oxygen, such as in patients who are bleeding or have anemia. White blood cells are given to patients with life-threatening infections that reduce the white blood cell count. Platelets are often given to patients with blood clotting disorders, such as hemophilia or von Willebrand's disease. Plasma also helps with blood clotting, and is often transfused in patients with liver failure. Immunoglobulins are the disease fighting components of blood and are also given to build up immunity, especially in patients who have been exposed to an infectious disease or whose antibody levels are low, such as those with AIDS.

How do I prepare for this procedure?

If you know you will be undergoing surgery, you may want to donate your own blood a month before your surgery. This is called an autologous transfusion, and the blood you donate is stored at the hospital for your use only. If you need a transfusion during or after surgery, your own blood will be used. Or, you could ask a friend or family member with the same blood type to donate blood specifically for you. This is called a direct donation. Many people feel more comfortable knowing the source of the blood for a transfusion. However, the medical community has adopted stringent screening methods to ensure blood transfusions are extremely safe. Blood donors must answer questions about their general health, lifestyle, and any medical conditions that might disqualify them as donors. All donated blood is carefully checked for viral hepatitis, AIDS, syphilis, and other viruses. No blood is used until all test results have shown that it is safe. If you have had allergic reactions to previous transfusions, you should make sure your doctor is aware of this. Treatments are available so transfusions can be given to people who have had allergic reactions.

How is this procedure performed?

All donated blood is classified by type, either A, B, AB, or O, and as RH-positive or RH-negative. To protect the recipient, the blood is matched to his or her blood type. Before starting the transfusion, the healthcare professional cross-matches the donor blood by mixing a drop of it with the recipient's to make sure they are compatible. The healthcare professional will also double-check that the blood is intended for the recipient. Then, the donor blood is given slowly, through an intravenous (IV) line directly into the veins. Blood transfusions are given in units, with one standard unit of blood equaling about one pint. During the transfusion, medical personnel watch the patient closely for any adverse reactions. When the transfusion is complete, a compress bandage is placed over the area where the needle had been inserted.

People with heart disease are given transfusions even more slowly to avoid overloading the body with fluid. People with serious diseases that haven't responded to other treatments might benefit from a transfusion method called hemapheresis. Hemapheresis is a process that purifies the blood by removing blood from the patient, cleaning the harmful components from it, then returning the purified blood to the patient. Cytapheresis is a type of hemapheresis that removes excess amounts of certain blood cells. It might be used to treat conditions such as polycythemia, leukemia, and thrombocytosis. Another type of hemapheresis called plasmapheresis removes harmful substances from the plasma. This treatment might be used for patients with Guillain-Barre syndrome and myasthenia gravis.

What can I expect after the procedure?

After a blood transfusion, you will be carefully monitored for any adverse reactions. An allergic reaction is indicated by swelling, rash, itchiness, dizziness, fever, and headache. When blood is mismatched, the recipient's blood reacts to the transfused red blood cells and destroys them. This is called a homolytic reaction. Symptoms may include general anxiety or discomfort, then breathing difficulty, flushing, a feeling of pressure in the chest, and severe back pain. It is rare for these types of reactions to be life threatening.

This information has been designed as a comprehensive and quick reference guide written by our health care reviewers.  The health information written by our authors is intended to be a supplement to the care provided by your physician.  It is not intended nor implied to be a substitute for professional medical advice.