Blood Transfusion TBL Flashcards
A 20 year old women is brought into A&E with massive bleeding following a road accident.
Why can a transfusion of blood (red cells) of the wrong ABO group to a patient be fatal?
The patient has anti-A or anti-B antibodies in their plasma, which activate complement fully, to haemolyse the red cells.
A 20 year old woman is brought into the Emergency Department with massive bleeding following a road traffic accident.
She needs blood (red cells) within 5 minutes, so there is not time to test her blood group. Which blood should we give in an emergency?
O negative
A 20 year old woman is brought into the Emergency Department with massive bleeding following a road traffic accident.
Which blood component will she need to replace all her coagulation factors (as depleted following massive bleeding, and very little present in stored red cells)?
FFP
A 20 year old woman is brought into the Emergency Department with massive bleeding following a road traffic accident.
For this component, which group should we give in an emergency?
AB
A 20 year old woman is brought into the Emergency Department with massive bleeding following a road traffic accident.
While she receives emergency transfusion, which tests will be needed to provide fully compatible blood for her?
ABO & RhD group and antibody screen
A 20 year old woman is brought into the Emergency Department with massive bleeding following a road traffic accident.
Her blood group results are as follows: her red cells agglutinate (form a clump) when tested with a known anti-A antibody reagent, but not with a known anti-B reagent. Her red cells also agglutinate when tested with a known anti-D reagent.
What ABO & RhD group does she have?
A positive
A 20 year old woman is brought into the Emergency Department with massive bleeding following a road traffic accident.
Her blood group results are as follows: her red cells agglutinate (form a clump) when tested with a known anti-A antibody reagent, but not with a known anti-B reagent. Her red cells also agglutinate when tested with a known anti-D reagent.
She stabilizes, then her mother comes in and asks about the risks of infection from blood transfusion.
Which infections are all blood donations tested for?
HIV, hepatitis B+C+E, HTLV and syphilis
A 25 year old pregnant woman needs 2 units of blood (red cells) because she had severe bleeding after delivering her baby. Her blood ‘group and screen’ results show she is group A RhD negative and she has an anti-E antibody. Which blood (red cells) should she be given?
Group A RhD negative, which is also E antigen negative
A 25 year old pregnant woman needs 2 units of blood (red cells) because she had severe bleeding after delivering her baby.
Her blood ‘group and screen’ results show she is group A RhD negative and she has an anti-E antibody.
The baby is group A positive.
What could happen if some of the baby’s red cells get into the mother’s circulation during delivery?
The mother can form anti-D antibodies
A 25 year old pregnant woman needs 2 units of blood (red cells) because she had severe bleeding after delivering her baby.
Her blood ‘group and screen’ results show she is group A RhD negative and she has an anti-E antibody.
The baby is group A positive.
Can formation of the antibody be prevented?
Yes – if the mother is given some anti-D antibody, to prevent this
A 24 year old woman receives O positive blood (red cells) in error: her own group is A negative.
Explain in terms of ABO group antigens and antibodies, what implications this has for this patient
Woman is group A so has A antigens (but no B antigens) on her red cells; so makes anti-B antibodies from birth.
She receives group O red cells, which have neither A nor B antigens on them – so the woman’s anti-B has no B antigens to interact with on the red cells. So no harmful transfusion reaction occurs.
A 24 year old woman receives O positive blood (red cells) in error: her own group is A negative.
Explain in terms of RhD group antigens and antibodies, what implications this has for this young woman.
Woman lacks D antigen. She has received RhD positive red cells, so her immune system recognises the RhD antigen present on red cells, as “foreign” and mounts an immune response, forming anti-D antibodies.
Implications for future: For this transfusion, there is no problem, but for any future transfusion, she must receive RhD negative red cells. If she is given RhD positive blood, her anti-D antibodies will interact with the RhD antigens on the red cells and cause a delayed haemolytic transfusion reaction, with anaemia and jaundice. As anti-D antibodies are IgG class antibodies, they can cross the placenta. So if she is pregnant and the fetus is RhD positive (as inherited the D antigen from the father), then her anti-D interacts with the RhD positive fetal red cells and causes haemolysis. The fetus becomes anaemic and if severe, may die; or after birth, the baby may have high bilirubin, which can cause brain damage or death.
A 24 year old woman receives O positive blood (red cells) in error: her own group is A negative.
1 year later, this woman needs cardiac surgery for a heart valve problem, on the afternoon surgery operations list. She will need 4 units of red cells, 1 unit of platelets and 3 units of fresh frozen plasma (FFP).
A new member of staff asks why they can’t take all of these from the Transfusion Lab first thing in the morning and keep them all in a box in the operating theatre, so they are closeby if needed.
Explain in terms of storage conditions, why this is not appropriate.
Red cells - must be kept in a blood fridge at 4±2˚C and can only be kept up to 5 weeks, to prevent bacterial proliferation, which could harm patients.
FFP - must be kept frozen, to preserve all the coagulation factors; at room temperature they start to degenerate so lose function within hours.
Platelets – must be kept at room temperature (22±2˚C) and agitated (on a mechanical rocker), to preserve platelet function– otherwise they don’t work well when transfused.
A 24 year old woman receives O positive blood (red cells) in error: her own group is A negative.
One year later, this woman needs cardiac surgery for a heart valve problem, on the afternoon surgery operations list. She will need 4 units of red cells, 1 unit of platelets and 3 units of fresh frozen plasma (FFP).
A new member of staff asks why they can’t take all of these from the Transfusion Lab first thing in the morning and keep them all in a box in the operating theatre, so they are closeby if needed.
How many blood donors would have been involved in providing all these blood components?
4 units of red cells = 4 donors;
3 units of FFP = 3 donors;
1 unit of platelets could be 4 donors (their platelets all pooled into 1 unit), or 1 donor (donating platelets on an apheresis machine);
Total = 11 or 8 donors.
A 24 year old woman receives O positive blood (red cells) in error: her own group is A negative. 1 year later, this woman needs cardiac surgery for a heart valve problem, on the afternoon surgery operations list. She will need 4 units of red cells, 1 unit of platelets and 3 units of fresh frozen plasma (FFP). A new member of staff asks why they can’t take all of these from the Transfusion Lab first thing in the morning and keep them all in a box in the operating theatre, so they are closeby if needed.
Each year, there are issues such as flu epidemics, snow from “Beast from the East”, Christmas holidays etc, so that there are largescale reductions in the number of donors coming to donate, for several weeks.
Explain, in terms of how long we can keep blood components for, why we can’t stockpile all components for months in advance, and which components we run short of first.
FFP (and cryoprecipitate) are not a problem, as kept frozen for up to 3 years, so can stockpile and wear peaks and troughs.
Red cells - up to 5 weeks; so can stockpile a few weeks’ worth before Christmas etc – but if sustained shortfall of donors, begin to run low. (NB: in “mass casualty event eg: bombing” have plenty for that but do need donors to donate over next few weeks. If all donate on the day of bombing, then all those units will expire on the same day 5 weeks later, if not all used! Much better to backfill the blood used for the bombing, over next 2-ish weeks. But hard to “sell” message on the day of the event and be hugely grateful to donors).
Platelets – only 7 day shelf life, because kept at room temp, so risk of bacterial proliferation, so restricted shelf-life. Run short of platelets first, if sustained shortfall of donors.
