Transfusion Flashcards
what is the minimum criteria for blood donation
Hb 135g/L men Hb 125g/L women Weight 50kg age 17-65 blood safety criteria (drugs, piercings, tattoos)
how long can red cells be stored for in a fridge (4 degrees)
35 days
how long can FFR -fresh frozen plasma be stored in the freezer
3 years
how long can platelets be stored at room temp
7 days
what blood products are produced from donated blood
Anti-D immunoglobulin
prothrombin complex concentrate
IV immunoglobulin
human albumin
specific Ig
what are red cell antigens
proteins on the cell surface of RBCs
about 36 groups of antigens
ABO = most important one for blood transfusion
what is the ABO system
red cells all have substance H, whether yours is A or B or O depends on your genes on chromosome 9
O-no sugary
A- one type of sugar
B- another type of sugar
you can have A and B at the same time
what are the most-least common ABO antigens
0- most common
A- common
B- less common
AB- rare
What is Landsteiner’s Law
if you’re blood group A you have the B antibody
if you’re group B you have the A antibody
If you’re group AB you have neither
If you’re group O you have A and B antibodies
why is Landsteiner’s law important
means you can’t be given blood with antigens which you have antibodies against
eg. group A cant receive B blood
but group AB can get any
what blood type is a universal donor - can use in emergency if you dont have a blood group
Blood group O because the cells have no antigens
people with group O blood can only receive O blood because of their antibodies
what is the next most important antigen after ABO
RhD- 85% of the population is RhD positive
what can anti-D antibody cause
transfusion reactions
haemolytic disease of the fetus and newborn
what happens if an Rh- person gets given Rh + blood
they produce anti-rhesus antibodies to destroy the Rh+ blood
what is done as pre-transfusion testing
identify ABO and RhD group of patient
Identify presence of clinically significant red cell antibodies
allow selection of appropriate blood for transfusion
how do you group ABO
use reagents with known antibodies to identify whats present on the new red cell (eg. test with anti A and anti B)
use red cells with known antigens to specify what antibodies are in the blood
both tests are done and should match
what is agglutination
when the antibody and antigen mix it causes clumping together of the blood
How is indirect anti globulin testing done
plasma is added to red cells with known antigens
add anti-human globulin
look for agglutination
What is an IAT crossmatch
agglutination indicated donor cells are incompatible with patient’s plasma
no agglutination - cells can be issues for transfusion
what are the indications for a red cell transfusion
Symptomatic anaemia Hb <70
Major bleeding
transfuse a single unit of red cells and then reassess patient
what are the indications for a platelet transfusion
prophylaxis in patients with bone marrow failure and v low platelet count
treatment of bleeding in thrombocytopenic patients
prophylaxis prior to surgery/procedure in thrombocytopenic patient
always consider cause before transfusion
what are the indications for fresh frozen plasma transfusion
treatment of bleeding in patients with coagulopathy (PT ration >1.5)
prophylaxis prior to surgery or procedure in patient with coagulopathy (PT ratio >1.5)
management of massive haemorrhage
transfuse early in anaemia
