FOR PHYSICIAN ASSISTANTS October 2002
nonhemolytic transfusion reactions.
of leukocytes helps prevent microaggregates
of white blood cells, fibrin, platelets and RBC
debris that form in stored blood.
It also helps
prevent HLA alloimmunization, nonhemolytic
febrile reactions, transmitting cytomegalovirus
(CMV) and benefits neonates and immuno-
Washed RBCs are prepared by washing the
blood cells with saline. Washing blood cells
removes donor antibodies and is useful in IgA
It is indicated for patients
with paroxysmal nocturnal hemoglobinuria.
The blood must be infused within 24 hours
after washing; otherwise it must be discarded.
Washing RBCs removes about 70% to 90% of
all white blood cells (WBCs).
Frozen RBCs are obtained by adding glycerol
to packed cells before freezing them. Frozen
RBCs can be stored for up to 10 years. The glyc-
erol must be removed before the cells can be
infused. The advantage of freezing RBCs is the
ability to stockpile unusual antigenic pheno-
types and obtain a large inventory of units.
Freezing removes about 95% of the total WBCs.
Frozen RBCs should be transfused within 24
hours after thawing.
Irradiation of blood products includes
platelet concentrates, whole blood, various
RBCs and granulocyte concentrates. Irradiation
of blood is indicated for patients at risk for
graft-versus-host disease from transfusion.
To prevent transmission of CMV infection,
blood components from random donors are
tested for CMV antibodies. Screened CMV
blood products are reserved for those at risk for
CMV infection. These include CMV-seronega-
tive pregnant women, premature infants born
to CMV-seronegative mothers, CMV-seronega-
tive recipients of allogenic bone marrow trans-
plants from CMV-seronegative donors and
CMV-seronegative patients with AIDS.
Blood filters are more efficient in removing
leukocytes and debris. Filters remove 99.9% of
WBCs from blood products. The filter is hung
at bedside and decreases the need for washed
blood cells. Filters should be replaced after
one to two units have been transfused.
Platelet transfusions are administered to
prevent or treat bleeding in thrombocytopenic
patients and patients with inherited platelet
Most prophylactic transfusions are
for counts less than 20,000/µL. Bleeding
patients may be transfused at platelet counts
much higher than that. Unless patients hem-
orrhage, platelets should not be transfused
when diagnosed with immune thrombocy-
topenic purpura, thrombotic thrombocy-
topenic purpura and hemolytic uremic syn-
drome. Platelets can be given as pooled con-
centrates or apheresis products. Pooled
platelets need to be transfused within four
hours. Each platelet unit contains about 5.5 x
platelets. A single unit will increase the
platelet count about 10,000 in a 70 kg patient.
A platelet count should be obtained one hour
after transfusion. An accurate way of measur-
ing the platelet count is by the corrected
count increment (CCI):
CCI = post-transfusion platelet count – pre-
transfusion platelet count/number of platelets
transfused by 10
x body sur face area (m
A CCI value of at least 5,000 should be seen.
Fresh Frozen Plasma
Plasma is separated from whole blood and
stored at -18 degrees C within eight hours of col-
lection. Once thawed, fresh frozen plasma (FFP)
is stored at 1 degree C to 6 degrees C and must
be transfused within 24 hours. FFP is most fre-
quently transfused to replenish multiple coagu-
lation factors in patients with documented coag-
ulation abnormalities who are bleeding or at risk
of bleeding during surgery.
FFP is used for
replacement of individual coagulation factors
that are not available as concentrates (factors II,
V, X and XI) and management of thrombotic
FFP is occasionally
used to replace hemostatic regulatory proteins
such as antithrombin III, protein C or protein S.
FFP also is given to patients who are bleeding
while on Coumadin with vitamin K deficiency
or before vitamin K reverses Coumadin’s effect.
Cryoprecipitate is indicated for the treatment
of factor XIII deficiency and fibrinogen defi-
ciency. One unit of cryoprecipitate per 5 kg
will increase fibrinogen by approximately 75
It is used as an alternative treatment
for von Willebrand’s disease and hemophilia A
(factor VIII:C deficiency). One unit of cryopre-
cipitate raises the factor level by 40 U/dL for
Table 2: ABO Blood Groups
Cells of Person Tested With Serum of Person Tested With
Table 3:Blood Type Compatibility Char t
Blood Type Recipient
Donor Red Cells
Donor Whole Blood
Any B or AB
Any B or AB
Any B or AB
Any B or AB
Platelets—ABO identical or compatible units are preferred but not required.Rh compatibility is
recommended in children and women of childbearing years to prevent antibody formation.
Single Donor Cr yoprecipitate—All ABO groups acceptable.
Type O blood is known as the universal donor.
Type AB blood is known as the universal recipient.