Blood transfusion Flashcards
(22 cards)
What is blood screened for before donor transfusion?
- HIV
- Hep E
- Hep C
- Hep B
- HTLV
- Syphillis
How long can red cells be stored for?
- 35 days
How long can FFP be stored for?
- 3 years frozen
How long can platelets be stored for?
- 7 days
Explain red cell antigens?
- inherited from parents
- foreign antigen -> antibody formation
- 2nd exposure can cause reaction
Explain the ABO system?
- chromosome 9
- 2 copies
- a and b cause h substance
- o is silent
What is Landsteiner’s law?
- when someone lacks A or B antigen
- exposure to natural antigen can cause antibody formation
ABO blood types?
- A
- B
- AB
- O
Antibiodies for each ABO group
- A = anti b
- B = anti a
- AB = neither
- o = anti a and anti b
Donor group O can be given to what recipient groups?
- O
- A
- B
- AB
- As no antigens present
Donor group A can be given to what recipient groups?
- Group A
- AB
Explain the Rh system
- 2 alleles D and d
- d is silent
- anti-d antibody can cause reaction
Explain antisera
- known antibody specificity to identify antigens present on red cell
Explain reagent red cells
- red cells of known antigen specificity to identify antibodies in plasma
How is ABO grouping performed?
- antisera (identifying antigens)
- reagent red cells (identifying antibodies)
Agglutination positive in ABO grouping means?
- incomparable
What type of reagent red cell is used in ABO grouping?
- IgM
Explain how antibody screening is performed?
- test patients plasma against several reagent red cells which express a known range of antigens
- add anti-human globulin
How is donor recipient cross matching conducted?
- donor red cells
- add patient plasma
- add anti-human globulin
- look for agglutination
What are the indications of a red cell transfusion?
- symptomatic anaemia Hb < 70g/l
- major bleeding
What are the indications for a platelet transfusion?
- prophylaxis in patients with bone marrow failure and very low platelet count
- treatment of bleeding in thrombocytopenia patients
- prophylaxis for surgery in thrombocytopenia patientis
Indications for a FFP transfusion
- treatment of bleeding in patient with coagulopathy pT>1.5
- Prophylaxis for patient with a coagulopathy
- transfuse early in trauma
