Blood Transfusion

Question 1

What are the 2 main blood group systems?

Answer 1

1- ABO
-Type A agglutinogen (b type A)
-Type B agglutinogen (b type b)
-Both A agglutinogen (b type AB)
Neither agglutinogens (b type O)
2- Rhesus
-Type D (Rh pos= D pos, Rh neg= no D antigen)

Question 2

What are the blood types and their corresponding antibodies in the plasma?

Answer 2

B type O- anti A & anti B
B type A- anti B
B type B- anti A
B type AB- none

Question 3

is it possible to develop anti- Rh antibodies?

Answer 3

Yes, it is acquired in either childbirth or mismatched transfusions. Can lead to haemolytic incompatibility.

Question 4

What is the process of storing blood?

Answer 4

1- Blood sample is spun separate red cells from plasma & platelets.
2- White cells are filtered out (leucodepletion).
3- Tested for pathogens and blood type- avoid infection + mismatching.
4- Adding preservatives- extend shelf life (Sodium citrate bind calcium & prevent clumping, dextrose =energy).

Question 5

What is the typical shelf life of blood cells?

Answer 5

Whole blood: 21/35 days
RBC: up to 42 days
Platelets: 5 days
Plasma and cry precipitated AHF: 1 year

Question 6

What steps need to be taken prior to a transfusion?

Answer 6

1- Blood grouping: determining red cell antigen in blood of donor and recipient
2- Crossmatching: agglutination (clumping) in presence of an antibody. if this happens, then blood is incompatible with recipient.

Question 7

What is the universal donor and the universal recipient?

Answer 7

1-Donor: B type O Rh neg. Can be in emergency to PTs with A, B, AB & Rh pos blood groups. May not be suitable if large volume = antibody titres.
2- Recipient: B type AB Rh pos.

Question 8

What are the most common transfusion reactions?

Answer 8

1- Febrile non-haemolytic
2- Haemolytic reaction: agglutination in rare cases, but more commonly minor rise in plasma bilirubin with ^ severity to renal damage, anuria and death.

Question 9

What is Haemolytic disease of the newborn?

Answer 9

Mother Rh-, father Rh+, foetus Rh+. Transfer of foetal Rh+ antigen to maternal circulation at birth stimulates production of anti-Rh antibodies in mother. Rh antibodies cross placenta in subsequent pregnancies leads to agglutination & haemolysis of foetal RBCs.

Question 10

What is the sole prevention of Haemolytic disease of newborn?

Answer 10

Routine administration anti-D antibodies post-partum. Reduced the incidence of disease by >90%

Question 11

what are autologous transfusions?

Answer 11

-Pre-deposit of blood prior to event e.g surgery and re-infused post. Can also be salvaged during surgery and re-infused.
-^ demand due to blood borne viruses.