1.3 Principles of transfusion medicine Flashcards Preview

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Flashcards in 1.3 Principles of transfusion medicine Deck (31):
1

Which antibodies can cross the placenta?

IgG

2

If you are blood type A what antigens and antibodies do you have?

Antigen A
Antibody Anti-B

3

If you are blood type AB what antigens and antibodies do you have?

Antigens A and B
No antibodies

4

If you are blood type O what antigens and antibodies do you have?

No Antigens
anti-A and Anti-B antibodies

5

What extra sugars do blood types A and B have?

A: n-acetyl galactosamine

B: Galactose

6

What blood type is the universal donor and why?

O because there are no antigens on the surface so no one will recognise them as foreign

7

What blood type is the universal recipient and why?

AB as there are no antibodies in the blood to react

8

What blood type are the universal donor and receiver of plasma?

Donor: AB
Recipient: O

9

What are the structural genes of Rh?

RhD (present or absent)
RhCE (C c, E e)

10

What are the symptoms of an acute heamolytic transfusion reaction?

Uritcaria
Chest pain
Hypotension
Diffuse intravascular coagulation
Haemoglobinuria
Back pain
Acute renal failure

11

What is the most common cause of acute heamolytic transfusion reaction

Clerical error resulting in the wrong ABO group being given

12

What causes delayed heamolytic transfusion reaction

Previously formed antibodies which were not detected on the pre transfusion testing enter the system. These cells are coated with IgG and removed

13

What are the typical symptoms of delayed heamolytic transfusion reaction

Unexplained anaemia with or without jaundice typically 7-10 days after transfusion

14

What happens if a patient who is Rh - is given Rh + blood?

The donor will develop antibodies against Rh. This will remain in the system but not cause harm as there is no antigen for them to bind to.If the patient is given a subsequent transfusion with Rh + there will be a reaction as the previously formed antibodies have an antigen to bind to

15

How does haemolytic disease of teh newborn occur?

Rh - mother has a Rh+ baby. The blood will cross teh placenta into the mothers cirulation. The mother will create antibodies againt the Rh (anti-D). In subsequent pregnancies the IgG can cross the placenta into the fetus and coat the fetal red cells leads to reticuloendotheilal destruction of teh RBCs. Can lead to anaemia, jaundice, hydrops, fetal death and hyperbilirubinaemia

16

How does haemolytic disease of the newborn occur?

Rh - mother has a Rh+ baby. The blood will cross the placenta into the mothers circulation. The mother will create antibodies against the Rh (anti-D). In subsequent pregnancies the IgG can cross the placenta into the foetus and coat the foetal red cells leads to reticuloendotheilal destruction of teh RBCs. Can lead to anaemia, jaundice, hydrops, foetal death and hyperbilirubinaemia

17

How does haemolytic disease of the newborn occur?

Rh - mother has a Rh+ baby. The blood will cross the placenta into the mothers circulation. The mother will create antibodies against the Rh (anti-D). In subsequent pregnancies the IgG can cross the placenta into the foetus and coat the foetal red cells leads to reticuloendotheilal destruction of the RBCs. Can lead to anaemia, jaundice, hydrops, foetal death and hyperbilirubinaemia

18

What can you do as prevention?

Give Rh - women anti-D IM at 28 and 34 weeks pregnancy. Anti-D will coat the +ve D cells preventing the mother from forming Anti-D memory B cells

If the mother delivers a Rh + baby you will also give a dose 72 hours post partum

19

How does haemolytic disease of the newborn occur?

Rh - mother has a Rh+ baby. The blood will cross the placenta into the mothers circulation. The mother will create antibodies against the Rh (anti-D). In subsequent pregnancies the IgG can cross the placenta into the foetus and coat the foetal red cells leads to reticuloendotheilal destruction of the RBCs. Can lead to anaemia, jaundice, hydrops, foetal death, kernicterus (CNS damage) and hyperbilirubinaemia

20

What can you do as prevention?

Give Rh - women anti-D IM at 28 and 34 weeks pregnancy. Anti-D will coat the +ve D cells preventing the mother from forming Anti-D memory B cells

If the mother delivers a Rh + baby you will also give a dose 72 hours post partum

If you do intervention such as amnio or the mother had bleeding in early pregnancy you would also give it then

21

What test can you do to check for immune mediated haemolysis?

Direct coombs test - will detect presence of antibody coasted red cells in circulation

22

How are red cells stored?

In citrate dextrose adenosine at 2-6 degrees for up to 42 days

23

How are platelets stored?

Room temperature for 5 days

24

How is FFP/cryoprecipitate stored?

Frozen at -20 for up to 12 months

25

When do you use platelets?

To prevent or stop bleeding in patients with severe thrombocytopaenia or platelet dysfunction

26

When do you use FFP?

To replace clotting factors (wont have all clotting factors)

27

What is present in cryoprecipitate?

Factor VIII, vWF, fibrinogen and factor XIII

28

What are examples of plasma derived products?

Albumin
IV immunoglobulin
Specific coagulation fatcors
Specific immunoglobulins

29

What test do you use for antibody screening?

Direct coombs test
Patient serum is incubated with a panel of red cells expressing a wide variety of common antigens and anti-IgG
If antibodies are present there will be agglutination

30

What test do you use for antibody screening?

Direct coombs test
Patient serum is incubated with a panel of red cells expressing a wide variety of common antigens and anti-IgG
If antibodies are present there will be agglutination

31

What are the possible transfusion reactions?

Acute heamolytic transfusion reaction
Anaphylaxis
Anaphalyactoid reaction
Sepsis
Febrile non-hameolytic transfusion reaction
Uritcaria
Transfusion related acute lung injury
Delayed haemolytic tranfusion reaction
graft vs. host disease
post transfusion purpura