Blood transfusion is a medical treatment to replace blood
or portions of the blood lost through injury, surgery, or disease.
What is the greatest risk of a transfusion?
greatest risk of having a blood transfusion is a
transfusion reaction. A transfusion reaction may be
mild or severe, and a severe reaction can be life-threatening. Transfusion
reactions occur when there is an imperfect match between your blood and the
blood you are given. Most adverse reactions occur because of an administrative
error, either mislabeling of a unit of blood by the laboratory or misreading of
the label by the doctors and nurses before the blood is given to you. Because
of the potential for a serious reaction, great care is taken to prevent these
labeling and reading errors. A transfusion reaction occurs about once in every
14,000 transfusions.1 It is possible to have a mild
transfusion reaction even if your blood and the blood given are properly
Some people, especially those who have had several blood
antibodies against certain components in the blood
they receive. The
immune system mistakes the new blood as harmful and
tries to destroy it. Careful screening helps reduce the risk for these
The risk for an
administrative error is the same whether you bank your own blood before surgery
or receive a transfusion of donor blood. It is also possible for an
administrative error to result in your receiving the correct blood type but not
the blood you banked before your surgery.
What is the risk of infection from a transfusion?
The transmission of viral infections, such as
HIV, through blood transfusions has become very rare
because of the safeguards enforced by the U.S. Food and Drug Administration
(FDA) on the collection, testing, storage, and use of blood. The risk of
infection from a blood transfusion is higher in less developed
It is possible for blood to become contaminated with
bacteria during or after donation. Transfusion with blood containing bacteria
can result in a systemic bacterial infection. The risk for this is the same
whether you bank your own blood before surgery or receive a blood transfusion
of donor blood.
Is there a risk in banking blood before surgery?
Because blood cannot be stored very long, you must bank your blood a few
weeks before your surgery. This may not allow sufficient time for your body to
make enough new blood to replace what you banked for your surgery. You may have
less blood than normal at the time of the surgery and so be able to tolerate
less blood loss before needing a transfusion. In some cases, it is possible
that you would not have needed a transfusion at all if you had not banked blood
before your surgery.
Can I bank enough blood to cover my surgical need?
Most people are able to safely bank 2 to 4 units of blood before surgery.
If you are having major surgery that may require a greater amount of blood than
this, you probably cannot bank enough blood before the surgery.
Talk with your surgeon to estimate the amount of blood you might need for
If you need more information, see the topic