What Is Whole Blood?
Whole blood is simply our blood as it flows in our bodies – with none of its
components separated or removed. In medicine, whole blood is an uncommon
type of transfusion. It is used to treat patients who need large amounts of all the
components of blood, such as those who have sustained significant blood loss
due to trauma or heart surgery.
What Are the Components of Blood?
Whole blood is made up of red blood cells, white blood cells and platelets, all of
which are suspended in a liquid called plasma. Whole blood and each of it’s four
components are all valuable tools in modern medicine.
How Much Blood Is in the Human Body?
The amount of blood in a person’s body depends on their size (the bigger the
person’s body is, the more blood it will contain). A newborn baby’s body will
contain only around a cup of blood whereas a 150-180 lb. adult will have
approximately 1.2-1.5 gallons (or 10 units) of blood in their body. Blood is
approximately 10% of an adult’s weight.
Red Blood Cells, White Blood Cells and Platelets All Constitute What
Part of Whole Blood?
Our red blood cells, white blood cells and platelets, make up about 45% of the
volume of our blood. The remaining 55% is liquid plasma.
How Are Whole Blood Donations Used?
Whole blood is used to help patients in 2 ways. It can be transfused into a single
patient. Whole blood can also be separated into its specific components of red
cells, plasma and platelets. These components can be given to different
patients, which is why we say that a donation of one unit or pint of whole blood
can help multiple people. (Although white blood cells are sometimes used in
medicine, they are not derived from a whole blood donation.)
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Why Donations Are So Important?
Recent studies show that there is a need for blood transfusions every 2
seconds. Whole blood is the simplest, most common type of blood donation. An
appointment to donate whole blood can take as little as one hour, and the actual
donation is only 8-10 minutes of that time.
Learn More About Blood Components
Platelets
Plasma
Red Blood Cells
Cryoprecipitate
Whole Blood
Hematocrit
White Blood Cells
Whole blood (WB) is human blood from a standard blood donation. It is
used in the treatment of massive bleeding, in exchange transfusion, and when
people donate blood to themselves. One unit of whole blood (~517 mls) brings
up hemoglobin levels by about 10 g/L. Cross matching is typically done before
the blood is given. It is given by injection into a vein.
Side effects include red blood cell breakdown, high blood
potassium, infection, volume overload, lung injury, and allergic reactions such
as anaphylaxis. Whole blood is made up of red blood cells, white blood
cells, platelets, and blood plasma. It is best within a day of collection; however,
can be used for up to three weeks. The blood is typically combined with
an anticoagulant and preservative during the collection process.
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The first transfusion of whole blood was in 1818; however, common use did not
begin until the First and Second World Wars. It is on the World Health
Organization's List of Essential Medicines. In the 1980s the cost of whole blood
was about US$50 per unit in the United States. Whole blood is not commonly
used outside of the developing world and military. It is used to make a number
of blood products including packed red blood cells, platelet
concentrate, cryoprecipitate, and fresh frozen plasma.
Medical use
Whole blood has similar risks to a transfusion of red blood cells and must
be cross-matched to avoid hemolytic transfusion reactions. Most of the reasons
for use are the same as those for RBCs, and whole blood is not frequently used
in high income countries where packed red blood cells are readily
available. However, use of whole blood is much more common in low and middle
income countries. Over 40% of blood collected in low-income countries is
administered as whole blood, and approximately a third of all blood collected in
middle-income countries is administered as whole blood.
Whole blood is sometimes "recreated" from stored red blood cells and fresh
frozen plasma (FFP) for neonatal transfusions. This is done to provide a final
product with a very specific hematocrit (percentage of red cells) with type O red
cells and type AB plasma to minimize the chance of complications.
Transfusion of whole blood is being used in the military setting and is being
studied in pre-hospital trauma care and in the setting of massive transfusion in
the civilian setting. Whole blood can be ABO-type specific when the recipient
blood type is known. For unknown recipient type, low-titer O universal donor
whole blood (LTOWB) can be used; this requires that the donor plasma contains
only low titers of anti-A and anti-B.
Processing
Historically, blood was transfused as whole blood without further processing.
Most blood banks now split the whole blood into two or more
components, typically red blood cells and a plasma component such as fresh
frozen plasma. Platelets for transfusion can also be prepared from a unit of
whole blood. Some blood banks have replaced this with platelets collected
by plateletpheresis because whole blood platelets, sometimes called "random
donor" platelets, must be pooled from multiple donors to get enough for an adult
therapeutic dose.
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The collected blood is generally separated into components by one of three
methods. A centrifuge can be used in a "hard spin" which separates whole blood
into plasma and red cells or a "soft spin" which separates it into plasma, buffy
coat (used to make platelets), and red blood cells. The third method is
sedimentation: the blood simply sits overnight and the red cells and plasma are
separated by gravitational interactions. Preparing a pooled buffy coat
concentrate may provide additional advantages.
Storage
Whole blood is typically stored under the same conditions as red blood cells
and can be kept up to 35 days if collected with CPDA-1 storage solution or 21
days with other common storage solutions such as CPD.
If the blood is used to make platelets, it is kept at room temperature until the
process is complete. This must be done quickly to minimize the warm storage
of RBCs in the unit.
Citrate-phosphate-dextrose solution with adenine (CPDA) is an anticoagulant
and preservative for storage of blood. It can prolong red blood cell storage life
up to 35 days. It maintains platelet viability. Usage of CPDA improves post-
transfusion visibility and improves glucose and ATP levels in blood.
