Pre/Neonatal and Infant Transfusion Flashcards
In general why do we need to be more careful with neonatal transfusion?
Neonates are a lot more unstable then adults
It is much easier to metabolically unbalance babies
How is a neonate defined
Infants up to 28 days post birth
However requirements for blood remain the same until over 1 year of life
What is the most common type of transfusion in neonates
Top-up transfusions most common especially in premature babies
Why is transfusion so common in neonates, especially premies?
Premies are born with less HbA then full term babies
HbF is converted to HbA at birth -> noticable drop in Hb before coming back up again as HbA is formed
Babies will often need a transfusion during this low Hb period
What is the significance when transfusion neonates?
They are our longest living survivors of a BT
Thus they are at risk of long-term consequences of transfusion i.e. symptoms of complication not until later in life
When transfusing neonates what considerations should always be made?
Every effort should be made to reduce transfusions
Reduce donor exposure as well hence split paedi packs from one donor
What donors are required for neonatal blood?
Donors must have previously donated blood in the past two years
Blood must be negative for all mandatory microbiology markers etc
What two main markers must neonatal blood be negative for?
Leucocyte depleted -> all components except granulocytes have to be LD
Cytomegalovirus -> CMV serology negative -> LD if in emergence and CMV - not available
Why can LD blood be used as a replacement for CMV- blood in an emergency?
CMV resides in leukocytes
therefore CMV- blood = LD blood
Therefore LD blood is considered CMV safe
As it is very unlikely to cause infection in immunocompetent or even in a baby
How do we crossmatch blood for babies, why is this?
Neonates up to 4 months old will have any blood crossmatched against the mothers plasma as it takes up until this point for babys immune system to kick in
What would be the four reasons why an IUT would be needed?
HDN
Parvovirus
Twin to Twin
FMH (severe)
What are some reasons why a neonatal top-up transfusion would be needed?
Anaemia of prematurity
Iatrogenic
ECMO: if baby requires cardiothoracic surgery etc -> causes haemolysis requiring top-up
Talk about parvovirus infection?
Infection from animals
It can cause aplastic anaemia in utero or in immunocompromised
Hence need for IUT
What is meant by Iatrogenic
This means caused by a doctor i.e. a clinician taking to many blood samples from a baby with a tiny blood volume
1ml + 1ml + 1ml etc all add up and can make baby anaemia and thus requiring a transfusion
What Hb do we try to maintain in neonates
Try to keep Hb above 12 or 10
-> try to maintain high Hb thats seen at birth
Hb will drop to 8.5 after a few weeks
Changing physiology of newborns - hence need for strict criteria for transfusion
What pre-transfusion testing is done
Group and screen on maternal plasma
ABO and Rh forward group on infant sample
DAT on infant red cells
What should you do if no maternal serum is available to do reverse grouping?
Screen infants serum for atypical antibodies used an indirect antiglobulin technique
NB: you probably wont have enough though as you only get 1ml of whole blood
What kind of crossmatching is done if no atypical antibodies are present and the DAT of infant is negative?
No cross-matching is necessary for first 4 months of life
Why do we see many DAT positives in labs today?
Due to RADP
Probably not HDFN but have to be investigated anyways
what are the four main considerations that have to be applied to blood components for neonates?
Smaller blood volume
Reduced metabolic capacity
Higher haematocrit due to HbF
Immature immunological system
What is the estimated blood volume of a newborn?
80-85ml/kg of body weight
Normally a baby is 3-4 kilos
Premie is 2 kilos
What two things can be toxic to a baby?
Mannitol and potassium
What might cause hypocalcaemia in babies?
Citrate in preservatives
Baby’s have an immature immune system, why is this an important consideration?
This can put baby at risk of graft versus host disease whereby donor cells can take over bone marrow especially in pre-mature babies etc
Why dont we irradiate all blood?
This shortens the shelf life due to potassium leakage
How do we avoid potassium leakage in blood for babies?
We use fresh blood which is less than 5 days old
give an example of where a baby will have to go for ecmo?
If baby is born with heart valve issues
What is a babys blood volume per kg?
10-20mls per kg
How old is the blood used for paedi packs?
First unit transfused must be less than 5 days old
Sequential units can be 7, 10, 35 days old etc
What temperature blood is used for neonatal transfusion, why is this?
All blood must be prewarmed
Babies cannot control their body temperature
Cold blood would result in hypothermia and therefore acidosis
What additive is found in paedi packs and why?
CPD is used and not SAGM
This is because Mannitol in SAGM is toxic -> nephrotoxic -> adults can deal with this in small quantities but small baby kidneys cannot
Adults can also produce allergic reactions to this
What neonatal units must be irradiated?
Exchange or intrauterine transfusions
If baby requires an IUT and a following top up transfusion then both units will be irradiated
If only a top up required then blood does not need to be irradiated
What is one method of increasing haemoglobin in a newborn which is done by the clinicians at birth
Delayed cord clamping
The umbilical cord is raised so as to let any cord blood flow back into the newborn
Hb will increase
What are the ten risks when transfusing a neonate?
Graft vs Host disease
Cytomegalovirus transmission
Bacterial infection
Volume overload
Citrate toxicity
Rebound hypoglycaemia
Hypothermia
Thrombocytopenia after exchange transfusion
Manitol toxicity
Hyperkalaemia
Talk about the tragic case study whereby platelets were not irradiated for a baby
Mother experiencing NAIT
Mother had anti-HPA1a antibodies
Platelets were taken from mother and irradiated and given to baby
However irradiation was not done correctly
HLA was only half matched - most severe
Baby died 3 weeks later
When would is be dangerous to give a neonate plasma?
If the neonate or young child has necrotising enterocolitis
T and Tn antigens will be exposed and antibodies will be present in plasma
Talk about overload in neonates
TACO
Babies are actually more tolerant to this than elderly and we see less reports in this cohort
But it is likely to happen due to small volume
What metobolic affects can cause cardiac arrythmia in neonates
Hypocalcaemia
Magnesium
Talk about hypoglycaemia in neonates
Sugar present in CPD preservative
This sugar will cause an insulin release
Baby will then become hypoglycaemia after the transfusion
Talk about hyperkalaemia in neonates
High potassium
Seen if old blood is used
Reports of fatalities due to this
How are paedi packs made and why is this done
Made using multiple satellite bag systems
Whereby a single red cell unit is divided into multiple splits
This minimises exposure e.g. 5 splits from one donor
Mimimises risk of infection
When is hypothermia most seen in neonatal transfusion?
Exchange transfusion
especially large exchanges
Talk about hypothermia in neonates, why does it occur
Carried out if baby experiencing hyperbilirubinaemia
Blood must be pre-warmed to prevent hypothermia
If cold or even room temp blood is used babies experience increased metabolic rate, hypoglycaemia, acidosis, apnoeic episodes and eventually cardiac arrest
What temperature decrease would you see if rt blood transfused into a neonate?
0.7 to 2.5 degree drop
Effects of hypothermia on a neonate
Increased metabolic rate
Hypoglycaemia
Acidosis
Apnoeic episodes
Cardiac arrest
Talk about mannitol toxicity in neonates
If SAGM units used in high volume toxicity occurs -> wont occur if only for top up
Nephrotoxic
How does mannitol work as an additive
It prevents rbc haemolysis
Talk about hyperkalaemia in neonates
Potassium load of a unit above acceptable limits
Cardiac affects etc
What is the new method ebing looked at at preventing K+ leakage in paedipacks
In America theyre looking at using XRAY irradiation to reduce K+ leakage as seen from gamma irradiation
Gamma irradiation has to be done in IBTS -> time then for leakage to occur before transfusion
But with XRAY it can be done on the day of the procedure thus minimal leakage is seen
What is the acceptable amount of K+ for neonates
Less than 10 mmol
But normally we use 3-5mmol/L (normal for baby)
This K+ increases linearly in packs
What does hyperkalaemia induce?
Cardiac arrest
What are the three red cell products available for neonates
Rbcs in SAGM, LD, split into 5 units
Partially packed rbcs or whole blood, LD in CPD -> for neonatal exchange
Red cells high in Hct LD in CPDA for use in IUT and exchange
How many mls per split?
50mls
How are packed rbcs for exchange made?
Squeeze of the plasma
What are the requirements for a rbc unit for IUT
O-, Kell neg, lacking implicated rbc antigen
IAT crossmatch compatible with mother
HCT up to 0.7 or 0.85
CPD
Less than 5 days old
CMV negative
Irradiated less than 24 hours ago
HbS negative
Pre-warmed
What is the required Hct of a rbc unit for an IUT
0.7->0.85
What needs to be remebered when treating a neonate who has had a previous IUT
Any blood or platelets now needed will need to be irradiated
At 8 weeks the neonate will often have a hyporegenerative anaemia and will often require a top up (irradiated)
What are the requirements of a rbc unit for a small volume top up transfusion
Must be ABO compatible with mother and infant
IAT compatible with mother or if available the neonates (4 months +)
SAGM 35 days or CPDA less than 28 days
1 unit must be less than 5 days old
Hct 0.5-0.7
Transfuse 10-20ml/kg over 2-4 hours
Dedicate one paedipack to a patient (5 splits)
Irradiate if appropriate i.e. if IUT
Compare the shelf life of SAGM vs CPD
SAGM 35 days or CPDA less than 28 days
What methods are in place now to limit the need for a neonatal rbc transfusion?
Clinicians limit the number of blood samples they take
Delayed cord clamping
Guidelines implemented
Maximimse nutritional status iron folate
Training of staff in phlebotomy - prevents need for re-draw etc
Regular audits
Erythropoietin - limited use though as it takes too long for effects
Talk about the requirements of a partially packed neonatal exchange rbc unit
O-, lacking implicated rbc antigen
crossmatch with maternal plasma
Hct: 0.5-0.55 (UK) or o.4 to 0.5 (AABB)
CPDA or reconstitute
<5 days
CMV negative
Irradiated and transfused within 24 hours
HbS negative
Pre-warmed
What are the leading causes of death in neonatal transfusions
Single haplotype match and non-irradiated platelets
How does LD affect risk of TA-GVHD
Universal LD has greatly reduced TA-GVHD
Removes 3-4 logs total wbcs
Removes 3.5 logs CD3+ cells
LD will not prevent GVHD in the immunodeficient individuals e.g. bone marrow patients but it has been sufficient in doing so in all other cohorta
What are the four different platelet products available for neonates
Apheresis platelets
NAIT
In utero transfusion
Hyperconcentrate of platelets
Talk about apheresis platelets for neonates
A single apheresis donation is split into either two or three donations
One one donor exposed
Talk about platelet transfusions for NAIT, what anitbodies are most commonly causative
Usually HPA-1a (80-90% of cases) antibodies involved
HPA-5b negative platelets also a common need for IUT
When might in utero transfusion of platelets be needed
Can be used for NAIT
Often uses hyperconcentrate of platelets
Weekly transfusions of selected platelets given in utero to minimise risk of bleeding associated with foetal blood sampling
What is the conc of platelets in hyperconcentrate
120 x 10^9 platelets in 60mls plasma
What are the requirements of all neonatal platelets
CMV -
Irradiated
When can ABO incompatible platelets be used for neonates?
If not high titre antibodies
Can also remove plasma supernatant and resuspend in saline or PAS
-> IBTS looking to do this for apheresis platelets as at the moment only are pooled platelets are suspended in PAS and these arent suitable for neonates
What are the three plasma products available to neonates?
AB Octaplas LG in Ireland
Group AB FFP or same ABO group as infant -> UK
Group AB FFP with low titre anti-T => only in UK
NB: both UK products can be from either whole blood donors or apheresis donors
How is plasma treated in the UK
Methylene blue to pathogen inactive the plasma
What is Octaplas
A blend of A, B and AB plasmas with low titre antibodies intended for use as a universal plasma but used by the IBTS primarily for issue to AB patients
What percentage of neonates will receive Octaplas
Less than 0.3%
Why might a neonate need octaplas
To increase clotting times in preterm infants
in DIC where PT/APTT ratio >1.5 and neonate is at significant risk of bleeding
If undergoing an invasive procedure
Inherited coag factor deficiencies without available concentrates e.g. FV deficiency
When should a neonate not be given octaplas, what is not an indicator for use>
A volume replacment
If coag factor recombinant product is available
Talk about cryoprecipitate for neonates
Group AB cryoprecipitate used to be used
Used to make single units of approximately 20 mls
Fibrinogen concentrate is used instead today
UK still uses cryo
What are the requirements of a neonatal donor
Must have donated and tested negative for all mandatory virology markers in the past 2 yeats
Donors should not have had a transfusion
Donors should not have an antibody
DCT negative
C- and E- if RhD-
K-
CMV antibody negative
HbS negative
What labelling requirements are there for neonatal units
> 5days old
Filtered within 24 hours of donation
Negative haemolysin if group O
CMV Ab negative
K negative
Leucodepleted
HbS negative
When is Irradiation a requirement
IUT
Exchange transfusion
Top up after IUT
First or second degree relative or HLA matched donor
Proven or suspected immunodeficiency
Platelet IUT
Post platelet or rbc IUT
Allogeneic stem cell transplant
Hodkgins disease/NHL/leaukaemia
How does irradiation affect potassium
Doubles potassium
Decreases shelf life to 14 days
