transfusion reactions

Question 1

what are the acute transfusion reactions

Answer 1

Acute haemolytic (ABO incompatible)
Allergic/anaphylaxis
Infection (bacterial)
Febrile non-haemolytic
Respiratory
* Transfusion associated circulatory overload (TACO) more common than TRALI
* Acute lung injury (TRALI)

Question 2

timeframe of an acute transfusion reaction

Answer 2

less than 24 hrs

Question 3

timeframe of a delayed transfusion reaction

Answer 3

more than 24hrs

Question 4

what are the delayed transfusion reactions

Answer 4

Delayed haemolytic transfusion reaction (antibodies)
Infection - viral, malaria, vCJD
TA-GvHD
Post transfusion purpura
Iron overload

Question 5

what is ‘serious hazards of transfusion’

Answer 5

SHOT is a national reporting scheme for serious hazards of transfusion
Reports submitted by country and trends of error reports from different departments – rising in ED / theatres

Voluntary reporting

serious hazards divided into:
* pathological reactions - may not be preventable
* reactions probably/possibly preventable
* hazard caused by error

A+E is where mistakes happen commonly

Question 6

presentation of an acute reaction

Answer 6

rise in temp
rise in HR
fall in BP

sx can include:
* Fever,
* rigors
* flushing,
* vomiting,
* dyspnoea,
* pain at transfusion site,
* loin pain/ chest pain,
* urticaria,
* itching,
* headache,
* collapse

Question 7

monitoring for a transfusion

Answer 7

Baseline temp, pulse, respiratory rate, BP before transfusion

Repeat after 15 mins (as most, but not all, reactions will start within 15 mins) -if obs have changed - need to stop - could be ABO/anaphylaxis

Ideally repeat hourly and at end of transfusion (as occasionally reactions start after transfusion finished)

Question 8

summarise febrile non-haemolytic transfusion reaction

Answer 8

mild/mod
During / soon after transfusion (blood or platelets),
rise in temperature of 10C, chills, rigors

Common before blood was leucodepleted, now rarer

Have to stop or slow transfusion; may need to treat with
paracetamol - likely can re-start transfusion

Cause: White cells can release cytokines during storage

Question 9

summarise allergic transfusion reactions

Answer 9

common - esp plasma
mild/mod

uriticarial itchy rash
wheeze

during or after transfusion

have to stop/slow transfusion
IV antihistamines - treat and future prevention

cause
* allergy to plasma protein
* more common if have atopy/allergies

Question 10

summarise the transfusion reaction when wrong blood is transfused

Answer 10

severe fatal - shock
acute intravascular haemolysis - IgM

• restless
• chest/loin pain
• fever
• vomiting
• flushing
• collapse
• haemoglobinuria (later)
• low BP
• high HR
• high temp

stop transfusion
check blood and pt
samples for FBC, biochem, coag
repeat X-match and DAT

cause
* failure of bedside check
* wrong label
* lab error

Question 11

summarise bacterial contamination

Answer 11

severe/fatal

shock - low BP, high HR, temp
presents similar to ABO incompatability

cause
* bacterial growth -> endotoxin production -> collapse
* donor infection
* introduced in processing - env/skin
* plts > red cells > frozen (storage temp)

Question 12

how do we prevent bacterial contamination

Answer 12

donor questioning
clean arm
division of 1st 20ml into pouch - used for testing

look for abnormalities in bag - clumps, debris, brown plasma

if red cells out of fridge for 30 min - need to go back in for 6hrs
complete transfusion within 4h of leaving the fridge

plts - screen for bacteria before release, transfuse over 20mins

Question 13

summarise anaphylaxis as a transfusion reaction

Answer 13

severe/fatal
soon after start of transfusion

shock - low BP, high HR temp
breathless
wheeze
laryngeal and facial oedema

Question 14

mechanism of anaphylaxis after a blood transfusion

Answer 14

IgE Ab -> mast cell release of granules and vasoactive substances

Question 15

anaphylaxis with IgA deficiency

Answer 15

common
IgA ab form in response to IgA esp with plasma transfusion

minority have transfusion reactions

If IgA deficient – can get hold of appropriate blood but need warning

Question 16

transfusion related circulatory overload

Answer 16

TACO

present within 6hrs
like pul oedema
SOB
low sats
high HR and BP

CXR - fluid overload/cardiac failure
mod/severe/fatal

need to assess before transfuse
give diuretics before transfuse to make space if at risk

Question 17

cause of TACO

Answer 17

inattention to fluid balance

RFs:
* HF
* resp disease
* renal impairment
* hypo-albuminaemia (liver disease)
* fluid replacement
* diuretics
* v young
* v small
* old

Question 18

transfusion related acute lung injury

Answer 18

TRALI
severe/fatal
within 6hrs
sx similar to TACO
acute lung injury/ARDS
SOB
low sats
high HR BP

CXR - bilateral pul infiltrates

Question 19

mechanism of TRALI

Answer 19

anti- white cell Ab in donor (HLA or neutrophil Ab)
-> interact with ag in pt
-> aggregate white cells
-> stuck in pulmonary capillaries
-> release neutrophil proteolytic enzymes and toxic ox metabolites
-> lung damage

Question 20

prevention of TRALI

Answer 20

male donors for plasma and platelets
no pregnancy or transfusion - so no HLA/HNA Ab

Question 21

transfusion related reaction - infection

Answer 21

mo-yrs after transfusion
prevention - question donors, never 0 risk
Hep B > HIV > Hep C

All tested for Hep B, HIV, Hep C E HTLV1 CMV western nile virus, zika virus

Question 22

CMV infection after transfusion

Answer 22

v immunosuppressed (stem cell pt)
fatal

leucodepletion removes CMV

only give CMV -ve for pregnant women, and neonates

Question 23

parvovirus infection after transfusion

Answer 23

temporary red cell aplasia

affects foetus and pts with haemolytic anaemia

Question 24

v-CJD infection after transfusion

Answer 24

no test

exclude transfused patients as donors just in case

Question 25

delayed haemolytic transfusion reaction

Answer 25

mild/mod

1-3% transfused get ab to red cell ag that the7 lack -> alloimmunisation

if have another transfusion with same ag - Ab -> RBC destruction

-> extravascular haemolysis (IgG) -> takes 5-10days

Question 26

tests for delayed haemolytic transfusion reaction

Answer 26

high - BR, LDH, reticulocytes
low - Hb
DAT +ve
haemoglobinuria
UEs
repeat G&S for new Ab

Question 27

transfusion associated graft vs host disease mechanism

Answer 27

rare but always fatal - death wks-mos
donor blood contain some lymphocytes -> divide
normally donor’s immune system recognise them and kill
in immunosuppressed - cant
lymphocytes recognise pt’s HLA as foreign - attack gut, liver, disease, skin and marrow

Question 28

features of transfusion associated graft v host disease

Answer 28

severe diarrhoea,
liver failure,
skin desquamation,
bone marrow failure
death

Question 29

prevention of transfusion associated graft v host disease

Answer 29

irradiate blood components for v immunosuppressed or pts having HLA matched components

Question 30

post-transfusion purpura

Answer 30

appear 7-10 days after blood/plts
resolve in 1-4wks
can -> life threatening bleeding
affects HPA-1a -ve pts (prev immunised by preg/transfusion: anti-HPA-1a Ab)

mech:
* ?exact mechanism of own platelet destruction, as HPA-1a negative!
* ?innocent bystander mechanism

Treatment – infusion of IVIG

Question 31

immune modulation post-transfusion

Answer 31

Possible

increased rate of infections post-op

increased recurrence of cancers in patients who have blood transfusion

Question 32

iron overload post-transfusion

Answer 32

If lots of transfusion (e.g. >50 e.g. Thalassaemia / Sickle cell disease )

accumulate iron (not
excreted); 200-250mg of iron per unit of blood
-> organ damage - liver, heart, endocrine etc

Prevent by iron chelation (Exjade) with transfusions once ferritin >1000