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Saint Agnes Medical Center, Fresno, California
Got Questions About Blood?
This patient education tool will answer some of your questions about blood and blood transfusions. It will give you a better
understanding of:
• Blood and its different components
• Why you may need a transfusion
• How blood is screened and tested
• The risks of blood transfusion
• Alternatives to blood transfusion
BLOOD AND BLOOD COMPONENTS
Typically, each donated unit of blood, referred to as whole blood, is separated into multiple components:
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Red blood cells are the most recognizable component of whole blood. Red blood cells contain hemoglobin, an iron-containing
protein that carries oxygen throughout the body and gives blood its red color. A patient may require a transfusion of red blood
cells in the event of acute blood loss from trauma, surgery, gastrointestinal bleeding, or for chronic anemia resulting from bone
marrow disease, cancer or kidney failure.
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Plasma is the liquid portion of blood in which red and white blood cells and platelets are suspended. Plasma contains albumin
(the chief protein constituent), fibrinogen (responsible, in part, for the clotting of blood), globulins (including antibodies) and other
clotting proteins. Plasma is most often given to treat certain bleeding disorders. It can also be used for plasma replacement via a
process called plasma exchange.
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Platelets are very small cellular components of blood that help the clotting process by sticking to the lining of blood vessels.
Platelets are used to treat a condition called thrombocytopenia, in which there is a shortage of platelets, and to treat patients with
abnormal platelet function.
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Cryoprecipitate (antihemophilic factor) is the portion of plasma that is rich in certain clotting factors, including fibrinogen, Factor
VIII / von Willebrand factor, and Factor XIII. Cryoprecipitate is removed from plasma by freezing and then slowly thawing the
plasma. It is used to prevent or control bleeding in individuals with hemophilia and von Willebrand’s disease, which are common,
inherited major coagulation abnormalities.
WHAT TESTS ARE PERFORMED ON DONATED BLOOD?
After blood has been drawn, it is tested for ABO group (blood type) and Rh type (positive or negative), as well as for any unexpected
red blood cell antibodies that may cause problems in a recipient. An important step in ensuring safety is the screening of donated
blood for infectious diseases. Today, multiple tests for infectious diseases are conducted on each unit of donated blood and are listed
below:
• Hepatitis B
• Hepatitis C
• HIV / AIDS virus
Patient Education
2/23/07
Saint Agnes Medical Center, Fresno, California
•
•
•
•
HTLV
Syphilis
Nucleic acid amplification testing (NAT) for HIV and HCV (hepatitis C virus)
NAT for West Nile Virus
WHAT IS NUCLEIC ACID AMPLIFICATION TESTING (NAT)?
NAT employs testing technology that directly detects the genetic material of viruses. NAT detects a virus’s genetic material instead of
waiting for the body’s response (the formation of antibodies), as with many current tests. This offers the opportunity to reduce the
window period during which an infecting agent is undetectable by traditional tests, thus improving blood safety.
WHAT RISKS ARE ASSOCIATED WITH TRANSFUSION OF BLOOD PRODUCTS?
Although it can be said that the blood supply is safer than it has ever been, blood transfusions are still not guaranteed 100% safe.
Listed below are the risk ratios that are associated with transfusion of blood and blood components.
HIV
Hepatitis C
Hepatitis B
CJD (Mad Cow
disease)
West Nile Virus
1 : 2,000,000
Minor allergic
reactions
Bacterial infection
1 : 2,000,000
1 : 200,000
Acute Hemolytic
Transfusion reaction
Anaphylactic shock
No reported cases via
transfusion in the US
2003 – 6 cases in US
None reported in
2004 and 2005.
Immune suppression*
1 : 100
1 : 12,000 (platelets)
1 : 250,000 (red cells)
1 : 250,000
1 : 20,000
Unknown
*Some clinical studies have found a link between transfusions and suppression of the immune system. Multiple transfusions are also
linked to increased infection rates in post-operative patients. The length of time that red blood cells are stored can also affect their
shape and flexibility to pass through smaller blood vessels, and inhibit their ability to offload oxygen to tissues and vital organs.
ARE THERE ALTERNATIVES TO TAKING A BLOOD TRANSFUSION?
In situations where a person may have lost a large volume of their blood due to complex surgery, trauma or severe gastrointestinal
bleeding, transfusions of red blood cells, plasma and platelets may be the only immediate treatment option.
However, thanks to advances in equipment, techniques and technology, surgeries can be performed without the use of blood
transfusion in a wide variety of specialties, including general surgery, orthopedic, genito-urinary, and cardiovascular.
Medications are also available that may be used in a variety of settings to help in avoidance of blood transfusions:
• to stimulate production of red blood cells, white blood cells and platelets by the bone marrow
• to help reduce blood loss during and after an operation
TRANSFUSION FREE PROGRAM AT SAINT AGNES
The Transfusion-Free Medicine and Surgery Program at Saint Agnes is an innovative program designed to meet the needs of patients
who desire quality medical care without the use of donor blood. Using an integrated team approach, our highly skilled medical
professionals are committed to respecting the wishes of each patient and to providing safe and effective alternatives to blood
transfusion. If you would like more information on alternative strategies to blood transfusion or would like to enroll in our TransfusionFree Program, please request to speak with the Coordinator, Transfusion-Free Program, (559) 450-3357.
Patient Education
2/23/07