Blood Transfusion

Question 1

How do blood groups arise

Answer 1

Arise from antigens

Red cell antigens are expressed on the cell surface and provoke antibodies

Question 2

What is the Rhesus blood positive

Answer 2

Rhesus positive (RhD positive), it means that a protein (D antigen) is found on the surface of your red blood cells

Question 3

Depending on your blood group what antibodies do you have?

Answer 3

A- antibodies against B
B- antibodies against A
O- antibodies against A and B
AB- no antibodies against A and B

Question 4

What are the red cell donor/ recipient compatibility?

Answer 4

Donate:
O can donate to anyone
A and B can donate to A and B
AB can donate to A or B or AB

Recipients:
A from A, AB or O 
B from B, AB or O 
AB from A, B, AB or O
O from O

Question 5

What can RhD negative individuals make?

Answer 5

Can make anti-D if exposed to RhD+ cells

Via transfusion or pregnancy

Question 6

Blood components?

Answer 6

Plasma- clotting or coagulation factors, albumin, antibodies

Buffy coat- platelets, white cells or leuocytes

Red blood cells

Question 7

Indications for red cell transfusion

Answer 7

Correct severe acute anaemia,
Improve QofL in uncorrectable anaemia,
Prepare patient for surgery or speed up recovery,
Reverse damage from patients own red cells
-Sickle cell disease

Question 8

How are red blood cells stored and transfused?

Answer 8

Stored at 4degrees Celsius
Transfuse over 2-4 hours
1 unit increments

Question 9

Platelet storage

Answer 9

1 dose platelets
Stored at 22degreec
Shelf life for 7 days
Transfuse over 20-30 minutes

Question 10

when to use platelets

Answer 10

Massive haemorrhage (keep count above 75x10(9)/L)

Bone marrow failure (keep at <20x10(9)/L)

Prophylaxis for surgery (minor 50x10(9)/L major 80x10(9)/L or CNS/eye surgery (100x10(9)/L)

Cardiopulmonary bypass (only if bleeding)

Question 11

When is fresh frozen plasma indicated?

Answer 11

Massive haemorrhage,
DIC with bleeding,
Prophylactic

Allow 30 mins to thaw

Lab test- PT and APTT

Question 12

“Group and screening” for blood bank

Answer 12

Check:
ABO and RhD type,
Check against historical records,
Screen for allo-antibodies in serum

Question 13

What is Coombs test?

Answer 13

Direct:
Test detects antibodies that are stuck to the surface of the red blood cells:
Looks for- autoimmune haemolytic anaemia, passive anti-D, haemolytic transfusion reactions

Indirect:
Prenatal testing of pregnant women
Testing prior to a blood transfusion

Question 14

Blood tests that are normally done due to clinical significance

Answer 14

ABO 
Rh 
Kell 
Duffy 
S, s, U
P 
Kidd

Question 15

Why do you test pregnant woman for RhD blood type/

Answer 15

Rhesus negative blood (RhD negative) and the baby in her womb has rhesus positive blood (RhD positive) will cause rhesus disease

Anti-RhD antibodies produced by mother attack baby

Question 16

What is haemolytic disease of newborn (HDN)

Answer 16

RhD negative mother and RhD positive baby
Positive DAT (Direct Antiglobulin Test) at birth
Haemolysis,
Anaemia,
Jaundice

Question 17

Treatment for Haemolytic Disease of the Newborn

Answer 17

Prevention using prophylactic anti-D
Monitoring- antibody titres, Doppler ultrasound, intrauterine transfusions
Neonatal alloimmmune thrombocytopenia

Question 18

Examples of cellular therapies?

Answer 18

Leucapheresis

• bone marrow harvests,
• donor lymphocyte infusions

Other banks

• bone, milk, tendons, heart valves, faecal
• islet cells, mesenchymal stem cells