Transfusion Medicine Flashcards
What is the risk or transmission of HIC, HCV, HBV in blood transfusion
1 in 500,000…this will be on test
What is 1 unit of pbrc
250 ml of packed red blood cells…each unit raises Hb by 1 g/dl
How long can prbc packs be stored?
42 days
WHat happens after 42 days?
25% of transfued red cells will hemolyze after transfusion
Type A allele transfers what sugar to the “O” antigen?
GalNac
Type B transfers what sugar ?
Galactose
Type “O” transfers what sugar?
None. The enzme is inactive in the “O” form.
Two copies of A allele?
Type A blood
Two copies of B allele?
Type B
AB has both GalNac and Galactose
Yep
What antibodies do type A ppl make?
B antibodies
antibodies made by type B
A
Antibodies by AB?
None
What type of antibody is it?
IgM…fixes complement to th erecognized cell
What does antigenicity mean?
Its kinda like a measure of how much of an antigen something is. It is defined as the likelihood of an antibody binding site to induce an antibody response.
What is the most antigenic protein on red cell surface
RhD
You understand how RhD works
Its easy. Treat with Rhogam after first pregnancy
In who is it ok to transfer RhD+ blood to an RhD- pt?
old women and men. Never to women of childbearing age b/c they will develop an RhD antibody and can kill an RhD+ fetus.
Why do we screen transfusion recipients for red cell minor antibodies?
These can react with minor red cell antigens. If you find the antibody, you can usually find blood without the antigen
What is a crossmatch
Take doner blood and recipient blood and test for agglutination
What do you give in an emergency blood transfusion?
O-
Whats the lowest Hb level can healthy patients tolerate
7g/dl
What are the 3 real reasons to transfer blood
Increased HR or RR along with confusion weakness.
Acute blood loss
During or immediately after an MI
Mythical reasons to transfuse?
Old and frail
Asymptomatic coronary artery disease
To expand blood volume. NEVER, just use fluid
To promote wound healing. No doesn’t work
What transfusion strategy is better and what are the target levels for each>
Liberal- 10-12 Hb
Restictive- 7-9…THIS IS BETTER
