Blood Transfusion

Question 1

How regularly can you donate blood?

Answer 1

Donor gives approx. 1pint (unit) max. every 4 months

Question 2

 Blood shelf life is ….

Answer 2

5 weeks

Question 3

How are A and B antigens on RBC formed

Answer 3

by adding one or other sugar residue onto a common glycoprotein and fucose stem on red cell membrane

Question 4

How O group antigens on RBC formed

Answer 4

common glycoprotein and fucose stem on red cell membrane with no sugar

Question 5

What is added onto a common glycoprotein and fucose stem on red cell membrane in A blood group and by what enzyme

Answer 5

N-ACETYL GALACTOSAMINE

n-acetyl galactosamine transferase)

Question 6

What is added onto a common glycoprotein and fucose stem on red cell membrane in B blood group and by what enzyme

Answer 6

adds GALACTOSE (galactose transferase)

Question 7

• ‘A’ and ‘B’ genes are X

Answer 7

codominant

Question 8

O gene is X

Answer 8

recessive

Question 9

• Person has antibodies against any antigen XXX own red cells

Answer 9

not present on

Question 10

Which Ig causes haemolysis of red cells

Answer 10

IgM

Question 11

What antibodies are found in the plasma of people with O blood group

Answer 11

both anti A and anti B

Question 12

Which blood group can receive any blood

Answer 12

AB

Question 13

Which blood group can give blood to anyone

Answer 13

O

Question 14

What 2 antigens need to be matched for a blood transplant

Answer 14

RH and ABO

Question 15

What are the Rh blood groups

Answer 15

RhD is the most important one 
RhD positive (if have D antigen) or RhD negative (if not)

Question 16

• Genes for RhD groups (notation and genotype)

Answer 16

D Codes for D antigen on red cell membrane
d Codes for no antigen and is recessive

• dd= no D antigen RhD negative
• Dd or DD= D antigen present RhD positive

Question 17

Proportion of people RhD positive and negative?

Answer 17

• 85% of people are RhD positive, 15% negative

Question 18

Can People who lack the D antigen make anti-D antibodies, when?

Answer 18

Yes after RhD exposure through transfusion or if women fall pregnant with an RhD positive baby

Question 19

What type of Ig are anti D antibodies, what does this cause

Answer 19

IgG
Don’t fully activate the complement cascade Go as far as C3D stage, so you get antibody coated red cells and between 5-10 days later, these pass through the spleen and are destroyed by macrophages

Question 20

What does extravascular haemolysis cause

Answer 20

causes jaundice through the high bilirubin and the free haemoglobin damages kidney tubules

Question 21

What is HAEMOLYTIC DISEASE OF THE NEWBORN

Answer 21

If RhD neg mother has anti-D, and in the next pregnancy the foetus is RhD pos, the mother’s IgG anti-D anitbodies can cross the placenta causing haemolysis of foetal red cells if severe leads to hydrops fetalis, brain damage due to high bilirubin and even DEATH

Question 22

Why do we not give women who are child bearing age X type of blood

Answer 22

RhD positive blood to RhD negative women is never given to avoid haemolytic disease of the newborn

Question 23

What is used in an emergency to give blood

Answer 23

O neg

Question 24

RED CELLS:- Shelf life?

Answer 24

5 weeks

Question 25

RED CELLS: units/donor?

Answer 25

1

Question 26

RED CELLS: why do we not freeze?

Answer 26

Has a poor recovery when thawing

Question 27

FFP (fresh frozen plasma): storage conditions?

Answer 27

-30 degrees

Question 28

FFP (fresh frozen plasma): shelf life?

Answer 28

• Shelf life 2 years

Question 29

FFP (fresh frozen plasma): unit/donor?

Answer 29

• Shelf life 2 years

Question 30

FFP (fresh frozen plasma): time till use?

Answer 30

• Must thaw approx. 20-30mins before use:

 Give ASAP- ideally within 1 hour or coagulation factors degenerate at RTP

Question 31

FFP (fresh frozen plasma): units/dose?

Answer 31

• Dose 12-15ml/kg (usually 3 units)

Question 32

FFP (fresh frozen plasma): matching necessary?

Answer 32

• Need to know blood group, but X-match not necessary (as contains ABO antibodies, which could cause some haemolysis but not very much so not fatal)

Question 33

FFP indications? (3)

Answer 33

1. Patient bleeding AND abnormal coagulation test results (prothrombin time (PT)/activated partial thromboplastin time (APTT) abnormal) Monitor the response clinical and by coagulation tests
2. Reversal of warfarin (anticoagulant that depletes factors II, VII, IX and X) e.g. for urgent surgery (if prothrombin complex concentrate (PCC) unavailable)
3. Other conditions occasionally e.g. massive haemorrhage

Question 34

CRYOPRECIPITATE: storage conditions

Answer 34

same as FFP, -30

Question 35

CRYOPRECIPITATE: contains?

Answer 35

fibrinogen and factor VIII

Question 36

CRYOPRECIPITATE: indications?

Answer 36

• If massive bleeding and fibrinogen very low

- Rarely it can be used for hypofibrinogenaemia

Question 37

Fractionated products that can be used for blood transfers? (3)

Answer 37

• Factor VIII and IX:
• Immunoglobulins:
• Albumin:

Question 38

What disease has been transmitted via blood transfusion in the UK 4 times, what precaution is now taken to fix this?

Answer 38

Prion disease,

 All plasma pooled to make fractionated products now obtained from USA (UK plasma is sometimes used for FFP, but otherwise thrown away)
 All blood components have white cells filtered out (leucodepleted)- white cells are essential for uptake of vCJD prion into brain to cause disease