Transfusion Flashcards
what is the minimum criteria for men to donate blood?
Hb 135g/L and weight 50kg at least
what is the minimum criteria for women to donate blood?
Hb 125g/L and weight 50kg at least
the bag of whole blood is ———— to separate into component parts?
centrifuged
the blood samples are tested for? (6)
HIV, Hep B, Hep C, Hep E, HTLV, Syphilis
red cells are stored at?
4 degrees for 35 days
FFP is stored at?
-30 degrees for 3 years
platelets are stored at?
22 degrees for 7 days with agitation
what are the blood components available form the transfusion lab?
red cells, FFP, platelets, cryoprecipitate
what are the blood products available from the transfusion lab?
Anti D immunoglobulin, prothrombin complex concentrate
what are the blood products available from the pharmacy?
iv immunoglobulin, human albumin, specific Ig
what chromosome is the ABO system on?
chromosome 9
what are A and B genes?
they code for transferases which modify precursor called H substance on red cell membrane
A and B are ————- over O
dominant
A and B are?
co dominant
O is?
silent
what are the commonly encountered blood group in populations?
A and O group
what is the most common blood group?
O
what antigens are present on A group red cells?
A
what antigens are present on B group red cells?
B
what antigens are present in AB group red cells?
A and B
what antigens are present on O group red cells?
neither
what is the Lansteiner’s law?
when an individual lacks the A or B antigen the corresponding antibody is producing in their plasma
naturally occurring antibodies cause?
hemolysis of red cells expressing the specific antigen
what antibodies are present in the plasma of A group?
anti B
what antibodies are present AB group?
neither
what antibodies are present in O group?
anti-A and anti-B
which blood group can donate to all ABO groups?
O group
which blood group can only donate to its blood group and AB blood gorup>
A or B
which blood group can donate to AB blood group only?
AB
what is the next most important antigen after AA & B?
RhD
what percentage of the population are RhD positive?
85%
d in RhD is?
silent
avoid exposing RhD negative people to?
D antigen through transfusion eg. RhD negative blood to RhD negative people
Anti-D antibody can cause?
transfusion reactions and hemolytic disease of the fetus and newborn
what are the aims of pre-transfusion testing?
identify ABO and RhD group of patient
identity the presence of clinically significant antibodies
what reagents with known antibody specificity identify antigens present on red cells?
antisera
red cells with known antigen specificity identify antibodies present in plasma
reagent red cells
antigen on red cells bind to the antibody specific for antigen of interest?
agglutination of red cells
how does ABO/D groups work?
test the patient’s red cells with anti-A, anti-B and anti-D antisera: identify antigens on the red cells
test the patient’s plasma against reagent red cells of group A and group B - identify antibodies in the plasma
IgM reagents cause?
direct agglutination
how does antibody screening work?
test the patient’s plasma against several reagent red cells which express a known range of antigens
what is the aim of antibody screening?
identify antibodies in the plasma
use the indeirect anti-globulin test
what is the indirect anti-globulin test?
addition of anti-human globulin to plasma/red cells suspension facilitates red cell agglutination
in the indirect anti globulin test agglutination indicates?
presence of antibody
perform crossmatch?
to check donor cells are compatible with patients plasma
in IAAT agglutination?
indicated do not cells are incompatible with patient plasma
indications for red cells transfusion?
Symptomatic anaemia Hb<70g/L (80g/L if cardiac disease)
Major bleeding
indications for platelet transfusion?
Prophylaxis in patients with bone marrow failure and very low platelet counts
Treatment of bleeding in thrombocytopenic patient
Prophylaxis prior to surgery/ procedure in thrombocytopenic patient
indications for FFp transfusion.
Treatment of bleeding in patient with coagulopathy (PT ratio >1.5)
Prophylaxis prior to surgery or procedure in patient with coagulopathy (PT ratio >1.5)
Management of massive haemorrhage
Transfuse early in trauma
not in absence of bleeding/planned procedure
