Blood transfusion

Question 2

how is bloood processed and tested

Answer 2

• Bag of whole blood centrifuged to separate into component parts
  
  • Samples undergo microbiological testing - HIV, hep B, hep B, Hep E, HTLV, syphilis
  • Red cells stored at 4℃ for 35 days
  • FFP stored -30℃ for 3 years
    Platelets stored at 22℃ for 7 days with agitation

Question 3

blood components from a blood donation

Answer 3

red cells, fop , platelets , cryoprecipitate

Question 4

blood products from donation

Answer 4

anti-d immunoglobulin , pt complex conc

Question 5

blood products from pharmacy

Answer 5

iv immunoglobulin, human albumin, specific ig

Question 6

what is antigen expression determined by

Answer 6

which blood group antigen genes we inherit from our parents

Question 7

ABO system

Answer 7

• Coded for by the ABO gene which is located on chromosome 9
  
  • A and B genes code for transferases which modify precursor called H substance on red cell membrane
  • A and B are dominant over O
  • A and B are co-dominant
    O is silent

Question 8

landsteinersz law

Answer 8

If a specific antigen (agglutinogen) is present on the RBCs, the corresponding antibody (agglutinin) will be absent in the plasma

Question 9

aims of pre transfusion testing

Answer 9

○ Identify ABO and RhD group of patient
○ Identify presence of clinically significant red cell antibodies
This allows selection of appropriate blood for transfusion

Question 10

indications for red cell transfusion

Answer 10

• Symptomatic anaemia Hb < 70g/L (80g/L if cardiac disease)
  
  • Major bleeding
  • Always consider cause before transfusion and whether there is an alternative
    Transfuse a single unit of red cells and then reassess patient

Question 11

indications for platelet trransfusion

Answer 11

• Prophylaxis in patients with bone marrow failure and very low platelet counts
  
  • Treatment of bleeding in thrombocytopenic patients
  • Prophylaxis prior to surgery/procedure in thrombocytopenic patient

Question 12

indications for FFP transfusion

Answer 12

• Treatment of bleeding in patient with coagulopathy (PT ratio >1.5)
  
  • Prior to surgery or procedure in patient with coagulopathy (PT ratio >1.5)
  • Management of massive haemorrhage
  • Transfuse early in trauma
  • NOT indicated in abscence of bleeding/planned procedure even if coagulation screen abnormal

Question 13

monitoring during transfusion

Answer 13

• Observation before blood is commenced
  
  • Observations at 15 mins
    Observations within 60 mins of completion

Question 14

cryoprecipitate v ffp

Answer 14

cryo is more fibrinogen concentrated while FFP provides a broader range of clotting factors

cryo is derived from FFP

Question 15

what is the rhd antigen

Answer 15

protein found on surface of red blood cells

Question 16

rh positive v negative

Answer 16

○ If a person has the RhD antigen, they are Rh-positive (e.g., A⁺, B⁺, O⁺).
○ If they lack the RhD antigen, they are Rh-negative (e.g., A⁻, B⁻, O⁻).