Blood transfusion Flashcards
What blood groups are dominant and recessive?
A and B are dominant
O is recessive
a patient is blood group A and requires blood due to haemorrhage.
what blood types can she receive blood from?
A and O
a patient is blood group AB and requires blood due to haemorrhage.
what blood types can she receive blood from?
A, B, AB and O
a patient is blood group O and requires blood due to haemorrhage.
what blood types can she receive red cells from?
group O
a patient is at high risk of haemorrhage so you decide to give FFP.
their blood group is O. what type of donor can they receive FFP from?
A, B, AB and O
a patient is at high risk of haemorrhage so you decide to give FFP.
their blood group is AB. what type of donor can they receive FFP from?
group AB
a patient is at high risk of haemorrhage so you decide to give FFP.
their blood group is A. what type of donor can they receive FFP from?
A and AB
what type of antibody is anti-A / anti-B in blood?
IgM
what infections are blood donors screened for?
HIV
syphillis
hep B, C, E
what are the 3 blood components?
plasma - clotting factors, albumin and antibodies
buffy coat - leukocytes (WC’s) and platelets
red blood cells
what are some of the indications for a red cell transfusion?
severe anaemia which might otherwise cause organ damage
improve quality of life in someone with uncorrectable anaemia
prepare a patient for surgery or speed up recovery
reverse damage caused by the patients own cells i.e. sickle cell
how much is unit of red blood cells?
5 g/l
over how long is red blood cells transfused?
2-4 hours
over how long is platelets transfused?
20 - 30 mins
how much is 1 dose of platelets ?
20-40 x 10(9) /L
what are the indications of a platelet transfusion?
massive haemorrhage
bone marrow failure
prophylaxis for surgery
if bleeding with cardiopulmonary bypass
if a patient is blood group A+ and requires platelet transfusion due to bone marrow failure.
from what donor can she receive platelets from?
any blood group
you don’t require specific cross match for platelet transfusion as there are no antibodies/antigens in the buffy coat
what test can be used as an indicator of a patient requiring FFP?
PT and APTT
measure of clotting of the blood
when would a patient require FFP?
massive haemorrhage
DIC with bleeding
prophylactic
what transfusion is given to correct fibrinogen deficiency?
cryoprecipitate
how long does it take for FFP to thaw?
30 mins
when donating blood, how long is the sample valid for?
samples kept for 7 days but only valid for 2 days if recent transfusion
what happens when someone who is Rh-D negative becomes pregnant and the baby is Rh-D positive?
the mixi
what are the indications of the direct and indirect Coombs test?
direct;
- alloiummune haemolysis (i.e. HDN)
- drug induced immune-mediated haemolysis (i.e. penicillin, methyldopa)
- autoimmune haemolysis (i.e. SLE)
indirect;
- cross matching for blood transfusions
- antenatal screening for IgG causing potential HDN
in a massive haemorrhage, what immediate supply of blood products should you ask for?
6 units red cells
4 units FFP
1 unit platelets
in an emergency situation what blood type should you give a patient whose blood type you don’t know?
group O -ve
what is TA-GvsHD
transfusion associated graft vs host disease
a rare life threatening reaction in which the immunological competent donors T lymphocytes mount an immune response against the recipients lymphoid tissue
shortly after receiving a blood transfusion, a patient becomes breathless. what are the possible complications that could account for this?
how would you treat?
Transfusion associated circulatory overload (TACO)
Anaphylaxis
Transfusion related acute lung injury (TRALI)
- 02
- diuretic
- ventilation
- adrenaline
shortly after receiving a blood transfusion, urticaria develops on the patients arm. what are the possible complications that could account for this?
how would you treat?
mild allergic reaction
anaphylaxis
- anti-histamine
shortly after receiving a blood transfusion, a patient becomes pyrexic. what could be the cause of this?
how would you treat?
febrile non-haemolytic transfusion reaction
- anti-pyretic
what are the 2 main complications that can arise if a baby is coombs test positive at birth?
anaemia
jaundice
if a mother is Rh-D negative and the baby is Rh-D positive, what prophylaxis is given to prevent HDN?
the mother is given prophylactic anti-D at 28 weeks
at birth the baby presents healthily but starts to show pupura on their skin and on a blood test shows low platelets.
what is the diagnosis?
neonatal alloimmune thrombocytpenia (NAIT)
what is the difference between direct and indirect Coombs test? (anti globulin test)
used to detect antibodies which are bound to RBC surface
used to detect in vitro antibody-antigen reactions
what does a positive direct Coombs test indicate?
an immune mechanism is attacking the patients own RBC
what are the indications of cryoprecipitate?
bleeding due to thrombolytic therapy
hypofibrinogen
bleeding disorder i.e. von willibrands
would you transfuse a 76 year old with Hb 54 g/L and blood film consistent with megaloblastic anaemia?
no because she has either folic acid or vitamin B12 deficiency so you would give folate supplements and vitamin B12 injections
this will improve Hg within a week
would you transfuse a 48 year old lady admitted for a planned hysterectomy with Hb of 95 g/L?
no because she is obviously bleeding from her uterus hence why she is probably receiving a hysterectomy
e.g. menorrhagia
therefore just give some iron supplements and it will improve
what is the main way to determine clinically if a patient requires a blood transfusion?
if their blood volume is severely compromised
check pulse and blood pressure
they could lose a lot of blood but there Hg may still be normal therefore don’t reply on Hg level to determine if they require a blood transfusion
at what platelet level would you give platelet transfusion?
platelets < 15 x 10(9)
how is FFP stored and why is this of clinical significance?
frozen at -22 degrees and takes 30 minutes to thaw so have to pre plan if you are going to use it
would you transfuse a patient with DIC ?
only if they were bleeding
would you transfuse a patient with FFP who is hypotensive with an albumin content of 16 g/L?
no you would give human albumin as a plasma expander
would you give a patient FFP who is bleeding due to warfarin?
no you would give vitamin K + factor III and IV
what coagulation factors does cryoprecipitate contain?
Factor VIII and XIII
von willebrand factor
fibrinogen
fibronectin
why may platelets and red cells be irradiated before transfusion?
to decrease the risk of graft vs host disease in patients who are at risk i.e. immunosuppressed
