Blood Transfusion Flashcards
why transfuse blood?
mainly because of bleeding
failure of production
how do blood groups arise?
antigens
red cell antigens are expressed on cell surface
what is an antigen?
something that provokes an immune response
what can red cell antigens be made from?
proteins
sugars
lipids
the ABO gene codes for?
glycosyltransferase
with a graph describe the antibody response to antigens
see notes
what are glycans?
added to proteins or lipids on red cells
what do A and B genes code for?
transferase enzyme
what is A antigen?
N-acetyl-galactosamine
what is B antigen?
galactose
what is O gene?
non functional allele
what antigens does everyone have?
2 x D-galactose
N-acetylgalactosamine
N-acetylglucosamine
what inheritance is A and B and O?
A and B codominant
O is recessive
group A antibodies
B
group B antibodies
A
group O antibodies
A and B
group AB antibodies
No antibodies
what type of immunoglobulin for anti-A/B is naturally occuring?
IgM
IgG vs IgM
IgG needs protein
IgM ability to fix complement
table red cells donor recipient compatibility
see notes
table showing FFP donor/recipient compatibility
see notes
why is FFP the reverse of RBC?
plasma contains antibodies not antigens
when do rhesus negative individuals make anti-D
when exposed to RhD+ cells
what kind of protein is RhD?
transmemebrane
why is RhD immunogenic?
hydrophobic
what can anti-D cause?
transfusion
haemolytic disease of the newborn
what does DD mean?
RhD +ve
what does Dd mean?
RhD +ve
what does dd mean?
RhD -ve
what are blood donors screened for?
ABO, Rh hep B/C/E HIV syphilis (HTLV1, malaria, West Nile virus, Zika virus)
what kind of antibody is RhD?
IgG
what are the indications for red cell transfusion?
- to correct severe acute anaemia, which might otherwise cause organ damage
- to improve QoL in patient with otherwise uncorrectable anaemia
- to prepare a patient for surgery or speed up recovery
- to reverse damage caused by patient’s own red cells - Sickle cell disease
other than freezing plasma what can you do?
extract clotting factors and albumin
what temp should RBCs be stored at?
4 C
how long should you transfuse RBCs over?
2-4hrs
RBC 1 unit increments is?
5g/l
what does 1 dose of platelets =?
4 pooled
1 apheresis donor
platelets 1 dose increments?
20-40 10^9l
what temp should platelets should be stored at?
22 c
self life of platelets?
7 days
how long to transfuse platelets over?
20-30 mins
indications for platelets?
massive haemorrhage
bone marrow failure
prophylaxis for surgery
cardiopulmonary bypass
what is the first clotting factor to run out?
fibrinogen
in massive haemorrhage what do you want to keep platelet count above?
75 x 10^9/;
what is bone marrow failure in terms of platelets?
platelet count < 10-15 x 10^9/l
or <20 x 10^9/l if additional risk
platelets in prophylaxis for surgery
minor procedures 50x10^9/l
major 80x10^9/l
CNS or eye surgery 100x10^9/l
when would you use platelets in cardiopulmonary bypass?
only if bleeding
FFP is stored at what temp?
frozen
how long do you thaw FFP for?
30 mins
indications for FFP
massive haemorrhage
DIC with bleeding
prophylactic
indications for cryoprecipitate
fibrinogen low
how long to thaw cryroprecipitate for?
20 mins
if fibrinogen < 1.0g/dl how much cryoprecipitate?
1-2 pools
practical blood banking principles
Blood sent to Blood Bank ‘Second sample’ now implemented Group and Screen/Save Cross match Tariff defined by ’MSBOS’ Samples kept for 7 days But only valid for 2 days if recent transfusion
what type of near miss in blood banking is common?
patient not identified sample not labelled at bedside sample not labelled by person taking blood prelabelled bottle same surname
what is a group and save?
ABO and RhD type
checked against historical records
screen for allo-antibodies in serum
direct Coombs test
antibody already there
autoimmune haemolytic anaemia
passive antiD
haemolytic transfusion reactions
indirect Coombs test
Cross matching
describe Coombs test
anti-human immunoglobulin if get clumping
apart from ABO and Rh name some of the other most common
Kell Duffy MN P Lewis Lutheran
how many people have allo-antibodies in blood?
1-10%
what blood is available in minutes?
O -ve
what is urgent blood?
10-15 mins type specific (ABO/RhD)
what is non-urgent blood?
1 hr
full cross match
select correct ABO/RhD
if allo-antibodies choose antigen -ve blood
when may you need rapid control of bleeding?
obstetric intervention
surgery
interventional radiology
what does the massive haemorrhage protocol involve?
dedicated porter
6 units red cells
4 units FFP
1 unit platelets
never events in blood transfusion
death
harm due to ABO incompatability
other risks of blood transfuson
TACO TRALI ATR Febrile allergic vCJD risk
what is a prion disease?
transmittable by blood transfusion from early disease in sheep
steps taken to reduce risk of prion transmission in blood
leucodepletion
UK plasma not used for fractionation
imported FFP for all patients after 1996
management of blood reactions
stop transfusion
check patient identify against component label
consider: anaphylaxis, TACO, AHTR, bacterial infection, lung injury
acute transfusion reactions: pyrexia possible cause
FNHTR
acute transfusion reactions: pyrexia treatment
anti-pyretic
other symptoms usually more concern - shock/DIC
acute transfusion reactions: urticaria possible causes
mild allergic reaction
anaphylaxis
acute transfusion reactions: urticaria reatment
antihistamine
other symptoms usually more concern - bronchospasm/shock
acute transfusion reactions: dyspnoea causes
TACO
TRALI
anaphylaxis
acute transfusion reactions: dyspnoea treatment
O2
diuretic
ventilation
adrenaline
acute transfusion reactions: shock causes
IBCT
anaphylaxis
TRALI
TAS
acute transfusion reactions: shock treatment
adrenaline (IV) hydrocortisone/antihistamine IV fluid/ITU admission ventilation antibiotics FFP/platelets if DIC
what is haemolytic disease of the newborn?
development of maternal anti-D antibodies (Sensitisation)
IgG crosses placenta
most common antigens involved in haemolytic disease of the newborn
RhD - most immunogenic
also c, K
other Rh antigens, Jka, ABO less immunogenic
Positive DAT at birth, anaemia, jaundice
how to prevent haemolytic disease of the newborn
prophylactic anti-D
sensitising events
routine 28/40
treatment of haemolytic disease of the newborn
careful monitoring
antibody titres
doppler ultrasound
intrauterine transfusions
what is leucapheresis?
bone marrow harvests
donor lymphocyte infusions
other banks that are not blood
bone milk tendons heart valves faecal islet cells mesenchymal stem cells
name 3 cellular therapies
leucapheresis
other banks
gene therapies
what does TRALI stand for?
transfusion related acute lung injury
what is TRALI?
Tranfused anti-leucocyte Abs in donor plasma interact with patient’s WBC
Bilateral pulmonary infiltrate
Supportive management, ventilation
what does PTP stand for?
post transfusion purpura
what is PTP?
Tranfused anti-leucocyte Abs in donor plasma interact with patient’s WBC
Bilateral pulmonary infiltrate
Supportive management, ventilation
what is transfusion associated graft versus host disease?
Rare, but always fatal Graft of lymphocytes in donor’s blood transfused to an immunocompromised host Homozygosity of donor’s HLA type Can be prevented by irradiation of blood
