Blood Transfusions Flashcards
1
Q
What are reasons for transfusing blood?
A
- bleeding
- failure of production
2
Q
What determines blood groups?
A
- arise from antigens
- red cell antigens expressed on cells surface
- can provoke antibodies
- Type A- A glycoproteins
- Type B- B glycoproteins
- Type AB- A + B glycoproteins
- Type O- no glycoproteins
3
Q
Which blood donors groups are compatible with which blood recipient groups?
A
4
Q
What is RhD blood groups?
A
- RhD positive- RhD antigen/Rhesus positive
- RhD negative- no Rhd antigen/Rhesus negative
5
Q
What happens if an RhD negative individual is exposed to RhD+ blood cells?
A
- pregnancy or transfusion
- make anti-D
- anti-D cause transfusion reactions, haemolytic disease in newborns
6
Q
What are blood donors screened for?
A
- sex, age, travel, tattoos
- ABO + Rh blood grou
- Hep B/C/E, HIV, syphilis
- HTLV1, malaria, West Nile virus, Zika virus
7
Q
What are indications for red cell transfusions?
A
- severe acute anaemia, which may cause organ damage
- improve quality of life in uncorrectable anaemia
- prepare for surgery or speed recovery
- reverse damage caused by patients own cells
- sickle cell disease
8
Q
How are red blood cells stored and transfused?
A
- stored at 4˚C
- transfuse over 2-4 hrs
- 1 unit increments ~ 5g/L
9
Q
What are indications for platelets?
A
- massive haemorrhage
- bone marrow failure
- prophylaxis for surgery
- cardiopulmonary bypass
- use only if bleeding
10
Q
How are platelets stored and transfused?
A
- stored at ~22˚C
- shelf life 7 days
- transfused over 20-30 mins
11
Q
What are the components of plasma?
A
- fresh frozen plasma (FFP)
- 1 unit from 1 unit of blood
- stored frozen, 30 mins to thaw
- massive haemorrhage, DIC with bleeding, prophylactic
- cryoprecipitate
- 1-2 pool if fibrinogen < 1.0g/dl
- stored frozen, 20 mins to thaw
12
Q
What is the direct and indirect Coombs test?
A
- direct- detects antibodies on surface of RBC
- autoimmune haemolytic anaemia
- passive anti-D
- haemolytic transfusion reactions
- indirect- dectects free antibodies in blood
- cross matching
13
Q
What is haemolytic disease of the newborn (HDN)?
A
- erythroblasosis fetalis
- baby’s RBCs brake down at a fast rate
14
Q
What causes haemolytic disease of the newborn (HDN)?
A
- RhD -ve mother and +ve baby (most immunogenic)
- c, K
- other Rh antigens, Jka, ABO
- +ve DAT at birth, anaemia, jaundice
15
Q
What is the prevention and treatment for haemolytic disease of the newborn (HDN)?
A
- prevention using prophylactic anti-D
- sensitising events
- routine at 28/40
- treatment by careful monitoring
- antibody titres
- Doppler US
- intrauterine transfusions
- neonatal alloimmune thrombocytopenia (NAIT)
