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1. 23/11/15 22:35Frequently Asked Questions | Blood Donor Services | San Antonio, TX
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Blood Bank FAQs
How much blood is required for different procedures?
Coronary artery bypass surgery: 1-5 units
Fractured hip/joint replacement: 2-5 units
Cardiovascular surgery: 2-25 units
Bleeding Ulcer: 3-30 units
Brain surgery: 2-25 units
Auto Accidents/Gunshot wounds: Up to 50 units
Liver Transplants: Up to 50 units
Other organ transplants: Up to 10 units
Bone marrow transplant: Up to 2 a day
Sickle cell/Aplastic anemia: Up to 4 a month
What is the most common blood type?
The approximate distribution of blood types in the US population is as follows. Distribution may be different for specific racial and
ethnic groups.
O Rh-positive 38%
O Rh-negative 7%
A Rh-positive 34%
A Rh-negative 6%
B Rh-positive 9%
B Rh-negative 2%
AB Rh-positive 3%
AB Rh-negative 1%
In an emergency, anyone can receive type O Red Blood Cells, and type AB individuals can receive Red Blood Cells of any ABO type.
Therefore, people with type O blood are known as "universal donors¨ and those with type AB blood are known as "universal
recipients". In addition, AB Plasma donors can give to all blood types.
How much blood is in the body?
The amount of blood varies according to age, gender and weight. It is about 7 to 10% of the person's body weight. The average-
sized adult has about 10-12 pints of blood.
Are there different components that can be made from a unit of blood?
Yes, each unit of blood is normally separated into several components, leuko-reduced red cells, plasma, and platelets.
What are leuko-reduced red blood cells (LRBC)?
Leuko-reduced red cells help prevent blood transfusion reactions caused by white cells contaminating red cells and platelet
preparations and may reduce the likelihood of certain infections. A filtering process is used to remove the white cells from the unit.
RBC are circular, donut-shaped, flexible cells produced in the bone marrow. RBC take up oxygen in the lungs, deliver it to all of
your tissues, and take carbon dioxide back to your lungs to be exhaled. Each unit of RBC is normally separated into several
components. RBC may be stored under refrigeration for a maximum of 42 days.
What are white blood cells (WBC)?
WBC act as a primary defense line for the body against bacteria. Some types of WBC destroy invaders by engulfing them. Other
types produce antibodies against protein antigens of foreign material.
What are platelets?
Platelets are tiny, irregularly shaped cells made in the bone marrow. Once collected, their shelf life is only five days. They're needed
in your blood to plug small injuries to blood vessels and to start the clotting process. Platelets are important in the control of
bleeding and are generally used in patients with leukemia and other forms of cancer. Platelets are stored at room temperature and
may be kept for a maximum of five days.
What is plasma?
Plasma carries blood cells, nutrients, enzymes, hormones, and complex proteins through your body. Its proteins are essential in
helping your blood to clot. Fresh Frozen Plasma, used to control bleeding due to low levels of some clotting factors, is usually kept
in the frozen state for up to one year.

2. 23/11/15 22:35Frequently Asked Questions | Blood Donor Services | San Antonio, TX
Página 2 de 2http://www.universityhealthsystem.com/blood-bank-faqs/
What is Whole Blood Donation?
Whole blood donation is the collection of about one pint of blood from a vein in the arm. When blood is collected, it is drawn
through a sterile needle into a sterile plastic container. All blood collection supplies are sterile, used only once and then discarded.
What is my donated blood used for?
Donated blood is typed and tested in our laboratory and used by physicians for transfusion to ill and injured patients.