Blood Groups and Transfusion Flashcards
what is the NICE Hb threshold for blood transfusion
70
why is thethreshold for transfusion in those with ACS higher
anamaeia can worsen the ischaemia in ACS as Hb is needed to carry the oxygen = 80
what is the criteria that needs to be met to be a blood donor
Hb 135/125 men/women
weight 50kg
what 5 infections is the blood tested for
HIV, Hep B and C, syphillis, HTLV
which component of blood carries the highest risk of bacterial contamination
platelets as they are stored at room temp
why do you need to agitate platelets during storing
so they dont stick together
what is cryoprecipitate
a concentated source of fibrinogen and also contains factor VIII
which chromosome encodes the information for blodo groups
chromosome 9 codes for the antigens that are found on the RBC surface - A or B
how is rhesus group denoted on blood group
A+ - AO/AA and rhesus positive
is A or B gene dominant?
and O
co-dominant
dominate over O
what antigens do O RBCs express
none
what is Landsteiner’s law
if someone doesnt have eg an A antigen on their RBC surface the body wont know it and wil produce an antibody against it when it encounters a tiny bit of it in the gut (the bacteria there have similar appearance) = group B/O blood and anti-A antibody in plasma
how do you determine blood groups pres transfusion
test the patients RBCs with anti A B and D antisera
what further testing can be done to test for any clinically significant antibodies in the pt blood
indirect anti-globulin test
- take pt serum that would have the antibodies in it and add it to a donor blood sample in a test tube
- add Coombs solution
- if agglutination occurs there has been an antigen-Ab reaction
when doing a blood transfusion, how must you do it?
transfuse a single unit of RBCs and then reasses pt
