BLOOD TRANSFUSION
Learning objectives
After reading this chapter students should be able to:
1. Identify indications for blood transfusion
2. Mention types of blood component therapy
3. Know blood transfusion reactions and their preventions
Definition
Blood transfusion is the procedure of introducing the blood of a
donor, or pre-donated blood by a recipient into the recipient’s
bloodstream.
Indications for blood transfusion
The need for blood transfusion in patients with acute hemorrhage is
based on
• The volume lost
• The rate of bleeding
• The hemodynamic status of the patient; hematocrit may be normal
if determined.
• A patient with acute blood loss of more than 2000ml certainly
requires replacement of blood. It must be remembered that
crystalloid infusions should be provided while the blood compound is
obtained. For patients with chronic blood loss or chronic anemia
replacement of blood (RBC) should be based on the hematocrite
level. The optimal hematocrite is considered to be in the range of
30%. But patients with chronic anemia (e.g. renal failure) seem to
tolerate hematocrite as low as 18%-20%. Symptomatic patients
, exhibiting air hunger, dizziness, significant tachycardia or cardiac
failure should, of course, be transfused.
Component therapy is indicated when specific factor deficiencies are
demonstrated. For instance, factor VIII concentrates is the preferred
mode of therapy for classic hemophilia.
Compatibility tests If administrated blood is incompatible with the
patients own blood, life threatening reactions may result. Blood
banks routinely test for incompatibilities of the ABO and RH systems.
Cross matches allow for detection of rare antibodies (e.g. kell, duffy,
kidd) that are not detected in ABO and RH tests. Group-A contains
anti-B antibodies, Group-B contains anti-A antibodies, Group-O
contains anti-A and anti B antibodies. AB-group can receive any
blood.
Blood prepared after a full typing and cross match can be transfused
safely in 99.95% cases. In some instances when fully cross- matched
compatible blood is depleted or unavailable; type specific or O
negative blood should be given. Type O Rh negative blood can be
transfused without lysine the recipients blood.. Irregular recipient
antibodies cannot be detected and extra vascular hemolysis can also
occur. Overall, O negative blood, if randomly transfused, has a
serologic safety of about 99.8%.
Component therapy
Treatment of specific hematologic abnormality often requires only a
single component of whole blood. For example, factor VIII for classic
hemophilic or platelet transfusion for patients with bone marrow
suppression. Blood banks reduce the whole blood received from
donors to a variety of components. The available products include
whole blood, red blood cells, white blood cells, platelet concentrates
and plasma in several forms.
Learning objectives
After reading this chapter students should be able to:
1. Identify indications for blood transfusion
2. Mention types of blood component therapy
3. Know blood transfusion reactions and their preventions
Definition
Blood transfusion is the procedure of introducing the blood of a
donor, or pre-donated blood by a recipient into the recipient’s
bloodstream.
Indications for blood transfusion
The need for blood transfusion in patients with acute hemorrhage is
based on
• The volume lost
• The rate of bleeding
• The hemodynamic status of the patient; hematocrit may be normal
if determined.
• A patient with acute blood loss of more than 2000ml certainly
requires replacement of blood. It must be remembered that
crystalloid infusions should be provided while the blood compound is
obtained. For patients with chronic blood loss or chronic anemia
replacement of blood (RBC) should be based on the hematocrite
level. The optimal hematocrite is considered to be in the range of
30%. But patients with chronic anemia (e.g. renal failure) seem to
tolerate hematocrite as low as 18%-20%. Symptomatic patients
, exhibiting air hunger, dizziness, significant tachycardia or cardiac
failure should, of course, be transfused.
Component therapy is indicated when specific factor deficiencies are
demonstrated. For instance, factor VIII concentrates is the preferred
mode of therapy for classic hemophilia.
Compatibility tests If administrated blood is incompatible with the
patients own blood, life threatening reactions may result. Blood
banks routinely test for incompatibilities of the ABO and RH systems.
Cross matches allow for detection of rare antibodies (e.g. kell, duffy,
kidd) that are not detected in ABO and RH tests. Group-A contains
anti-B antibodies, Group-B contains anti-A antibodies, Group-O
contains anti-A and anti B antibodies. AB-group can receive any
blood.
Blood prepared after a full typing and cross match can be transfused
safely in 99.95% cases. In some instances when fully cross- matched
compatible blood is depleted or unavailable; type specific or O
negative blood should be given. Type O Rh negative blood can be
transfused without lysine the recipients blood.. Irregular recipient
antibodies cannot be detected and extra vascular hemolysis can also
occur. Overall, O negative blood, if randomly transfused, has a
serologic safety of about 99.8%.
Component therapy
Treatment of specific hematologic abnormality often requires only a
single component of whole blood. For example, factor VIII for classic
hemophilic or platelet transfusion for patients with bone marrow
suppression. Blood banks reduce the whole blood received from
donors to a variety of components. The available products include
whole blood, red blood cells, white blood cells, platelet concentrates
and plasma in several forms.
