blood transfusion

Question 1

When is a blood transfusion used?

Answer 1

• where one or more components of blood has to be replaced quickly (most commonly RBC
• transfuse clotting factors via plasma from donor
• transfusion when bone marrow cannot produce blood cells
• whole blood transfusion where blood is lost quickly
• sudden blood loss
• specific production problems in RBC, platelets, plasma proteins

Question 2

why should transfusions be avoided if possible?

Answer 2

• transfusion reactions where patients have reaction to incompatible blood
• transmission of infection, blood is screened for many known infections but new pathogens may not be caught

Question 3

What is the blood transfusion process?

Answer 3

• sample taken from patient
• tested against known blood types (basic ABO and rhesus compatibility)
• patient sample tested against donated sample to see if cross react
• successfully matched blood given to patient and patient is monitored

Question 4

what are surface antigens?

Answer 4

combination of different chains of sugar and protein.

Question 5

Describe blood group A.

Answer 5

• A antigen on surface of RBC
• has B antibodies in plasma
• Patient with A blood can receive O or A blood
• A1 or A2 surface antigens
• 20% are A2 and can have anti-A1 antibodies

Question 6

Describe blood group B.

Answer 6

• Displays B antigen on surface of RBC
• has A antibodies in plasma
• patient with B blood can receive B blood or O blood

Question 7

Describe blood group AB.

Answer 7

• Displays A and B antigens on the surface of the RBC
• No A or B antibodies in plasma
• Patient can receive A, B, AB or O blood
• A1B and A2B possible
• A2B can have anti A1 antibodies

Question 8

Describe blood group O.

Answer 8

• displays no surface antigens on RBC
• A and B antibodies in plasma
• O patient can only receive O blood

Question 9

Describe complications with transfusion.

Answer 9

• incompatible blood can cause RBC lysis, fever, jaundice and death
• fluid overload can overload CV system and cause heart failure
• transmission of infection (BBV-HepB, HepC, HIV, CMV; prion disease - vCJD; bacterial infection- syphilis)

Question 10

what is the D system/Rhesus system?

Answer 10

Rhesus (Rh) protein is found on the surface of RBCs. If your blood has the protein you are Rh positive and if not you are Rh negative. This is important In maternal foetal compatibility.

Question 11

Why is rhesus compatibility important in mother and child?

Answer 11

Only happens when mother is Rh negative carrying a baby who is Rh positive. The mothers immune system treats the babies Rh positive RBC cells, creates antibodies against them and destroys babies circulating RBC cells.