BLOOD TRANSFUSION
BLOOD TRANSFUSION, AUTOLOGOUS
in septicaemia. Microbiology also looks
for antibodies in the blood, which may
confirm immunity to an infection,
blood transfusion The infusion of large
volumes of blood or
blood products
directly into the bloodstream to remedy
severe blood loss or to correct chronic
anaemia.
In an exchange transfusion,
nearly all of the recipient's blood is
replaced by donor blood.
Before a
transfusion, a sample of the recipient's
blood is taken to identify the
blood
groups,
and it is matched with suitable
donor blood. The donor blood is trans-
fused into an arm vein through a plastic
cannula. Usually, each unit (about 500
ml) of blood is given over 1-4 hours; in
an emergency, 500 ml may be given in a
couple of minutes. The blood pressure,
temperature, and pulse are monitored
during the procedure.
If mismatched blood is accidentally
introduced into the circulation, anti-
bodies in the recipient's blood may cause
donor cells to burst, leading to
shock
or
kidney failure
. Less severe reactions can
produce fever, chills, or a rash. Reactions
can also occur as a result of an allergy
to transfused blood components. All
blood used for transfusion is carefully
screened for a number of infectious
agents, including
HIV
(the
AIDS
virus)
and
hepatitis B
and
hepatitis C.
In elderly or severely anaemic patients,
transfusion can overload the circulation,
leading to heart failure. In patients with
chronic anaemia who need regular trans-
fusion over many years, excess iron may
accumulate (haemosiderosis) and dam-
age organs such as the heart, liver, and
pancreas. Treatment with
desferrioxamine
to remove excess iron may be needed,
blood transfusion, autologous The
use of a person's own blood, donated
earlier, for
blood transfusion.
Autolo-
gous transfusion eliminates the slight
but serious risk of contracting a serious
infectious illness from contaminated
blood. There is no risk of a transfusion
reaction occurring as a result of incom-
patibility between donor and recipient
blood. Up to 3.5 litres of blood can be
removed and stored in several sessions
at least 4 days apart and up to 3 days
before planned surgery. Blood may be
salvaged during surgery, filtered and
returned to the circulation, reducing the
need for transfusion of donated blood.
BLOOD TRANSFUSION
Nurse
monitors
blood
pressure
Stethoscope
Sphygmomanometer
Blood enters
vein through a
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