Transfusion

Question 1

what is the minimum criteria for blood donation

Answer 1

Hb 135g/L men 
Hb 125g/L women 
Weight 50kg
age 17-65 
blood safety criteria (drugs, piercings, tattoos)

Question 2

how long can red cells be stored for in a fridge (4 degrees)

Answer 2

35 days

Question 3

how long can FFR -fresh frozen plasma be stored in the freezer

Answer 3

3 years

Question 4

how long can platelets be stored at room temp

Answer 4

7 days

Question 5

what blood products are produced from donated blood

Answer 5

Anti-D immunoglobulin
prothrombin complex concentrate

IV immunoglobulin
human albumin
specific Ig

Question 6

what are red cell antigens

Answer 6

proteins on the cell surface of RBCs

about 36 groups of antigens

ABO = most important one for blood transfusion

Question 7

what is the ABO system

Answer 7

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

Question 8

what are the most-least common ABO antigens

Answer 8

0- most common
A- common
B- less common
AB- rare

Question 9

What is Landsteiner’s Law

Answer 9

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

Question 10

why is Landsteiner’s law important

Answer 10

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

Question 11

what blood type is a universal donor - can use in emergency if you dont have a blood group

Answer 11

Blood group O because the cells have no antigens

people with group O blood can only receive O blood because of their antibodies

Question 12

what is the next most important antigen after ABO

Answer 12

RhD- 85% of the population is RhD positive

Question 13

what can anti-D antibody cause

Answer 13

transfusion reactions

haemolytic disease of the fetus and newborn

Question 14

what happens if an Rh- person gets given Rh + blood

Answer 14

they produce anti-rhesus antibodies to destroy the Rh+ blood

Question 15

what is done as pre-transfusion testing

Answer 15

identify ABO and RhD group of patient
Identify presence of clinically significant red cell antibodies

allow selection of appropriate blood for transfusion

Question 16

how do you group ABO

Answer 16

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

Question 17

what is agglutination

Answer 17

when the antibody and antigen mix it causes clumping together of the blood

Question 18

How is indirect anti globulin testing done

Answer 18

plasma is added to red cells with known antigens

add anti-human globulin

look for agglutination

Question 19

What is an IAT crossmatch

Answer 19

agglutination indicated donor cells are incompatible with patient’s plasma

no agglutination - cells can be issues for transfusion

Question 20

what are the indications for a red cell transfusion

Answer 20

Symptomatic anaemia Hb <70

Major bleeding

transfuse a single unit of red cells and then reassess patient

Question 21

what are the indications for a platelet transfusion

Answer 21

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

Question 22

what are the indications for fresh frozen plasma transfusion

Answer 22

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