What Is a Blood Transfusion?
A blood transfusion is a safe, common procedure in
which blood is given to you through an intravenous (IV) line in one of your
blood vessels. Blood transfusions are done to replace blood lost during surgery
or a serious injury. A transfusion also may be done if your body can't make
blood properly because of an illness.
During a blood transfusion, a small needle is used
to insert an IV line into one of your blood vessels. Through this line, you
receive healthy blood. The procedure usually takes 1 to 4 hours, depending on
how much blood you need.
Blood transfusions are very common. Each year,
almost 5 million Americans need a blood transfusion. Most blood transfusions go
well. Mild complications can occur. Very rarely, serious problems develop.
Important Information About Blood
The heart pumps blood through a network of arteries
and veins throughout the body. Blood has many vital jobs. It carries oxygen and
other nutrients to your body's organs and tissues. Having a healthy supply of
blood is important to your overall health.
Blood is made up of various parts, including red
blood cells, white blood cells, platelets (PLATE-lets), and plasma. Blood is
transfused either as whole blood (with all its parts) or, more often, as
individual parts.
Blood Types
Every person has one of the following blood types:
A, B, AB, or O. Also, every person's blood is either Rh-positive or
Rh-negative. So, if you have type A blood, it's either A positive or A
negative.
The blood used in a transfusion must work with your
blood type. If it doesn't, antibodies (proteins) in your blood attack the new
blood and make you sick.
Type O blood is safe for almost everyone. About 40
percent the population has type O blood. People with this blood type are
called universal donors. Type O blood is used for emergencies when there's no
time to test a person's blood type.
People with type AB blood are called universal
recipients. This means they can get any type of blood.
If you have Rh-positive blood, you can get
Rh-positive or Rh-negative blood. But if you have Rh-negative blood, you should
get only Rh-negative blood. Rh-negative blood is used for emergencies when
there's no time to test a person's Rh type.
Blood Banks
Blood banks collect, test, and store blood. They
carefully screen all donated blood for possible infectious agents, such as
viruses that could make you sick. (See "What Are the
Risks of a Blood Transfusion" for more information.)
Blood bank staff also screen each blood donation to
find out whether it's A, B, AB, or O and whether it's Rh-positive or
Rh-negative. Getting a blood type that doesn't work with your own blood type
will make you very sick. That's why blood banks are very careful when they test
the blood.
To prepare blood for a transfusion, some blood banks
remove white blood cells. This process is called white cell or leukocyte
(LU-ko-site) reduction. Although rare, some people are allergic to white blood
cells in donated blood. Removing these cells makes allergic reactions less
likely.
Not all transfusions use blood donated from a
stranger. If you're going to have surgery, you may need a blood transfusion
because of blood loss during the operation. If it's surgery that you're able to
schedule months in advance, your doctor may ask whether you would like to use
your own blood, rather than donated blood.
If you choose to use your own blood, you will need
to have blood drawn a few times prior to the surgery. A blood bank will store
your blood for your use.
Alternatives to Blood Transfusions
Researchers are trying to find ways to make blood.
There is currently no man-made alternative to human blood. However, researchers
have developed medicines that may help do the job of some blood parts.
For example, some patients with kidney problems can
now take a medicine called erythropoietin that helps their bodies make more red
blood cells. This means they may need fewer blood transfusions.
Surgeons try to reduce the amount of blood lost
during surgery so that fewer patients need blood transfusions. Sometimes they
can collect and reuse the blood for the patient.
Types of Blood Transfusions
Blood is transfused either as whole blood (with all
its parts) or, more often, as individual parts. The type of blood transfusion
you need depends on your situation.
For example, if you have an illness that stops your
body from properly making a part of your blood, you may need only that part to
treat the illness.
Red Blood Cell Transfusions
Red blood cells are the most commonly transfused
part of the blood. These cells carry oxygen from the lungs to your body's
organs and tissues. They also help your body get rid of carbon dioxide and
other waste products. You may need a transfusion of red blood cells if you've
lost blood due to an injury or surgery.
You also may need this type of transfusion if you
have severe
anemia
(uh-NEE-me-eh) due to disease or blood loss. Anemia is a condition in which
your blood has a lower than normal number of red blood cells, or the red blood
cells don't have enough hemoglobin (HEE-muh-glow-bin). Hemoglobinan
iron-rich protein that gives blood its red colorcarries oxygen from the
lungs to the rest of the body.
Platelets and Clotting Factor Transfusions
Platelets and clotting factors help stop bleeding,
including internal bleeding that you can't see. Some illnesses may cause your
body to not make enough platelets or other clotting factors. You may need
regular transfusions of these parts of your blood to stay healthy.
For example, if you have
hemophilia
(heem-o-FILL-ee-ah) A, you may need a special clotting factor to replace the
clotting factor you're lacking. Hemophilia is a rare, inherited bleeding
disorder in which your blood doesn't clot normally.
If you have hemophilia, you may bleed for a longer
time than others after an injury or accident. You also may bleed internally,
especially in the joints (knees, ankles, and elbows).
Plasma Transfusions
Plasma is the liquid part of your blood. It's mainly
water, but also contains proteins, clotting factors, hormones, vitamins,
cholesterol, sugar, sodium, potassium, calcium, and more.
If you have been badly burned or have liver failure
or a severe infection, you may need a plasma transfusion.
Who Needs a Blood Transfusion?
Blood transfusions are very common. Each year,
almost 5 million Americans need blood transfusions. This procedure is used for
people of all ages.
Many people who have surgery need blood transfusions
because they lose blood during the operation. For example, about one-third of
all heart surgery patients have a transfusion.
Some people who have serious injuriessuch as
from car wrecks, war, or natural disastersneed blood transfusions to
replace blood lost during the injury.
Some people need blood or parts of the blood because
of illnesses. You may need a blood transfusion if you have:
- A severe infection or liver disease that stops
your body from properly making blood or some parts of blood.
- An illness that causes
anemia,
such as kidney disease or cancer. Medicines or radiation used to treat a
medical condition also can cause anemia. There are many different types of
anemia, including
aplastic,
Fanconi,
hemolytic,
iron-deficiency,
and sickle
cell anemias and
thalassemia
(thal-a-SE-me-a).
- A bleeding disorder, such as
hemophilia
or thrombocytopenia (THROM-bo-si-to-PE-ne-a).
What To Expect Before a Blood Transfusion
Before a blood transfusion, a technician tests your
blood to find out what blood type you have (that is, A, B, AB, or O and Rh
positive or Rh negative). He or she pricks your finger with a needle to get a
few drops of blood or draws blood from one of your veins.
The blood type used in your transfusion must work
with your blood type. If it doesn't, antibodies (proteins) in your blood attack
the new blood and make you sick.
Some patients have allergic reactions even when the
blood given does work with their own blood type. To prevent this, your doctor
may prescribe a medicine to stop allergic reactions. (See
"What Are the Risks of a Blood Transfusion.")
If you have allergies or have had an allergic
reaction during a past transfusion, your doctor will make every effort to make
sure you're safe.
Most patients don't need to change their diet or
activities before or after a blood transfusion. Your doctor will let you know
whether you need to make any lifestyle changes prior to the procedure.
What To Expect During a Blood Transfusion
Blood transfusions take place in either a doctor's
office or a hospital. Sometimes they're done at the patient's home, but this is
less common.
A needle is used to insert an intravenous (IV) line
into one of your blood vessels. Through this line, you receive healthy blood.
The procedure usually takes 1 to 4 hours. The time depends on how much
blood you need and what part of the blood you receive.
During the blood transfusion, a nurse carefully
watches you, especially for the first 15 minutes. This is when reactions are
most likely to occur. The nurse continues to watch you during the rest of the
procedure as well.
What To Expect After a Blood Transfusion
After a blood transfusion, your vital signs are
checked (such as your temperature, blood pressure, and heart rate). The
intravenous line (IV) is taken out. You may have some bruising or soreness for
a few days at the site where the IV was inserted.
You may need blood tests that show how your body is
reacting to the transfusion.
Your doctor will let you know about signs and
symptoms to watch for and report.
What Are the Risks of a Blood Transfusion?
Most blood transfusions go very smoothly. However,
mild problems and, very rarely, serious problems can occur.
Allergic Reaction
Some people have allergic reactions to the blood
given during transfusions. This can happen even when the blood given is the
right blood type.
Allergic reactions can be mild or severe. Symptoms
can include:
- Anxiety
- Chest and/or back pain
- Trouble breathing
- Fever, chills, flushing, and clammy skin
- A high pulse or low blood pressure
- Nausea (feeling sick to the stomach)
A transfusion is stopped at the first signs of an
allergic reaction. The health care team determines how mild or severe the
reaction is, what treatments are needed, and if the transfusion can safely be
restarted.
Viruses and Infectious Diseases
Some infectious agents, such as HIV, can survive in
blood and infect the person receiving the blood transfusion. To keep blood
safe, blood banks carefully screen donated blood.
There is a risk of catching a virus from a blood
transfusion, but it's very low.
- HIV. Your risk of getting HIV from a blood
transfusion is lower than your risk of getting killed by lightning. Only about
1 in 2 million donations may carry HIV and transmit HIV if given to a patient.
- Hepatitis B and C. The risk of having a donation
that carries hepatitis B is about 1 in 205,000. The risk for hepatitis C is 1
in 2 million. If you receive blood during a transfusion that contains
hepatitis, you will likely develop the virus.
- Variant Creutzfeldt-Jakob disease (vCJD). Variant
CJD is the human version of Mad Cow Disease. It's a very rare, yet fatal brain
disorder. There is a possible risk of getting vCJD from a blood transfusion,
although the risk is very low. Because of this, people who may have been
exposed to vCJD aren't eligible blood donors. Go to the
AABB Web site for more information about vCJD.
Fever
You may get a sudden fever during or within a day of
your blood transfusion. This is usually your body's normal response to white
blood cells in the donated blood. Over-the-counter fever medicine will usually
treat the fever.
Some blood banks remove white blood cells from whole
blood or different parts of the blood. This makes it less likely that you will
have a reaction after the transfusion.
Iron Overload
Getting many blood transfusions can cause too much
iron to build up in your blood (iron overload). People with a blood disorder
like
thalassemia,
which requires multiple transfusions, are at risk of iron overload. Iron
overload can damage your liver, heart, and other parts of your body.
If you have iron overload, you may need iron
chelation therapy. For this therapy, medicine is given through an injection or
as a pill to remove the extra iron from your body.
Lung Injury
Although it's unlikely, blood transfusions can
damage your lungs, making it difficult to breathe. This usually occurs within
about 6 hours of the procedure. Most patients recover. However, 5 to 25 percent
of patients who develop lung injuries die from the injury. These people usually
were very ill before the transfusion.
Doctors aren't completely sure why blood
transfusions damage the lungs. Antibodies (proteins)which are more likely
to be found in the plasma of women who have been pregnantmay disrupt the
normal way that lung cells work. Because of this risk, hospitals are starting
to use men and women's plasma differently.
Acute Immune Hemolytic Reaction
Acute immune hemolytic reaction is very serious, but
also very rare. It occurs if the blood type you get during a transfusion
doesn't match or work with your blood type. Your body attacks the new red blood
cells, which then produce substances that harm your kidneys.
The symptoms include chills, fever, nausea, pain in
the chest or back, and dark urine. The doctor will stop the transfusion at the
first sign of this reaction.
Delayed Hemolytic Reaction
This is a much slower version of acute immune
hemolytic reaction. Your body destroys red blood cells so slowly that the
problem can go unnoticed until your red blood cell level is very low.
Both the acute and delayed hemolytic reactions are
most common in patients who have had a previous transfusion.
Graft-Versus-Host Disease
Graft-versus-host disease (GVHD) is when white blood
cells in the new blood attack your tissues. GVHD is usually fatal. People who
have weakened immune systems are the most likely to get GVHD.
Symptoms start within a month of the blood
transfusion. They include fever, rash, and diarrhea. To protect against GVHD,
patients with weakened immune systems should receive blood that has been
treated so the white blood cells can't cause GVHD.
Key Points
- A blood transfusion is a safe procedure in which
blood is given to you through an intravenous (IV) line in one of your blood
vessels.
- Blood is transfused either as whole blood (with
all its parts) or, more often, as individual parts. The individual parts
include red blood cells, platelets, clotting factors, and plasma.
- Every person has one of the following blood
types: A, B, AB, or O. Also, every person's blood is either Rh-positive or
Rh-negative. The blood used in a transfusion must work with your blood type. If
it doesn't, antibodies (proteins) in your blood attack the new blood and make
you sick.
- Blood banks collect, test, and store blood. They
carefully screen all donated blood so the right blood type is available for
your transfusion.
- Each year, almost 5 million Americans need blood
transfusions. This procedure is used for people of all ages.
- Many people who have surgery need blood
transfusions because they lose blood during the operation. People who have
serious injuries also may need blood transfusions to replace lost blood. Some
people need blood transfusions because they have illnesses that prevent their
bodies from properly making blood or parts of blood.
- Before a blood transfusion, a technician will
test your blood to find out what blood type you have. Your doctor may prescribe
medicine to prevent an allergic reaction. Most patients don't need to change
their diets or activities before or after a blood transfusion.
- When there isn't time to test for blood type
(such as during an emergency), type O blood is used. Type O is safe for almost
everyone.
- Blood transfusions usually take place in either a
doctor's office or a hospital. The transfusion takes 1 to 4 hours. The time
depends on how much blood you need and what part of the blood you receive.
- After a blood transfusion, your vital signs are
checked. You may need blood tests that show how your body is reacting to the
transfusion.
- Most blood transfusions go smoothly. However,
mild problems and, very rarely, serious problems can occur. They include
allergic reactions, transmission of viruses and infectious diseases, fever,
iron overload, lung injury, reactions from receiving the wrong blood type, and
immune system problems.
- There is currently no man-made alternative to
human blood. However, researchers have developed medicines that do the job of
some blood parts. Research is ongoing to find a way to make blood.
Links to Other Information About Blood
Transfusion
Non-NHLBI Resources
Clinical Trials
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