Pediatric Transfusion

Question 1

How does hydrops fetalis occur?

Answer 1

Fetal anemia suppresses production of albumin, in turn causing high output heart failure.

Question 2

Why isn’t kernicterus of concern before delivery?

Answer 2

Fetal bilirubin is eliminated by the mother.

Question 3

How does fetal doppler ultrasound influence need to transfuse?

Answer 3

1.5x MoM indicates severe anemia requiring transfusion

Question 4

What product requirements are applied to units for intrauterine transfusion?

Answer 4

Fresh, irradiated, washed, CMV-seronegative, HbS-negative, O-neg (OR MATERNAL) red cells that are crossmatch compatible with maternal plasma.

Question 5

What is the sensitivity of the rosette test?

Answer 5

Detects any fetomaternal hemorrhage greater than or equal to 10mL.

Question 6

What is the risk of maternal anti-D alloimmunization with, and without, RhIG?

Answer 6

16% without

0.1% with

Question 7

How is are weak D and anti-G managed in the prenatal setting?

Answer 7

Both may not necessarily require RhIG, but just give it anyway.

Question 8

How can RhIg be distinguished from true maternal anti-D?

Answer 8

Titers rarely exceed 4

No IgM component should be present (try to react with DTT)

Question 9

What is the cause of FNAIT?

Answer 9

80% of cases from HPA-1a antibodies
10% of cases from HPA-5b
Others: HPA-4b (asian), 1b, 3a…

Question 10

How severe is FNAIT? How is it treated

Answer 10

Quite severe. Develops fast and can often cause ICH. Treat with maternal IVIG, and IUT (plt, goal 50k for vaginal delivery).

Question 11

What causes maternal thrombocytopenia? How should it be managed?

Answer 11

Most cases are dilutional, but 4% are immunologic (eg. ITP). Transfuse mother to 50k for vaginal delivery, 80k for epidural/caesarian. Don’t worry about the kid in cases of ITP.

Question 12

What drives anemia of infancy?

Answer 12

Depression of EPO expression by the fetal liver which is habituated to the in utero hypoxic environment.

Question 13

In which children do AABB standards allow waiving of the second ABO/Rh and antibody screen?

Answer 13

Children under 4mo of age (insignificant expression of isohemagglutinins)

Question 14

What are the toxic effects of blood transfusion which can primarily affect neonates?

Answer 14

Hypothermia
Citrate toxicity (incl. acidosis)
Excess 2,3-DPG (avoid by using fresh blood)

Question 15

What are the advantages of using syringes for pediatric aliquoting?

Answer 15

More accurate volume measurements, and use of in-line filters.

Question 16

ARIPI

Answer 16

Trial which suggests no benefit to using fresh blood in VLBWs.

Question 17

How much of a baby’s RBCs and bilirubin does a double-volume blood exchange remove?

Answer 17

~80% of fetal RBCs

~50% of bilirubin

Question 18

What is the ideal product to be used in neonatal whole blood exchange?

Answer 18

Compatible pRBCs suspended in compatible FFP, reconstituted to baby’s hematocrit, and ideally also CMV/HbS neg with other special preps….

Question 19

What is the bilirubin cutoff for whole blood exchange? How long does it take to do a 2x blood volume exchange?

Answer 19

> 25mg/dL

Takes 90-120min to complete (do not transfuse faster than 5mL/kg/5min).

Question 20

What is a typical dose of red cells, plasma, and platelets in infants? Cryo?

Answer 20

RBCs: 10mL/kg
Plasma: 10-15mL/kg
Platelets: 5-10mL/kg
Cryo: No more than 1 unit.

Question 21

What can cause neonatal polycythemia, and how is it managed?

Answer 21

Maternal diabetes

Can be managed by exchange with blood reconstituted to the proper hematocrit.

Question 22

What is the association between necrotizing enterocolitis and blood transfusion?

Answer 22

Previously thought to be associated in some causative fashion, but now thought to be confounded by severe anemia.

Question 23

What are some transfusion goals in sickle cell disease? In thalassemia?

Answer 23

SCD: Target Hb 8-9g/dL with HbS <30%.
Thalassemia: Target Hb 8-10g/dL, manage iron overload.

Question 24

What causes anemia of infancy/prematurity?

Answer 24

Decrease in EPO expression (normally accustomed to relatively hypoxic in utero conditions). Also phlebotomy.

Question 25

What is the benefit of a 2x volume exchange transfusion?

Answer 25

Removes 90% of abnormal RBCs, 50% of bilirubin.

Question 26

How should crossmatching be done in neonatal settings?

Answer 26

May crossmatch against maternal plasma sample.

Question 27

What are some transfusion thresholds in the first 3 weeks of life?

Answer 27

Week 1: 10g/dL (more if respiratory support needed)
Week 2: 8.5g/dL (more etc)
Week 3: 7.5 g/dL

Question 28

What is the benefit vs cost of delayed cord clamping?

Answer 28

Delayed cord clamping increases red cell mass and immune response and reduces coagulopathy. However, can cause hyperviscosity and more bilirubin load.

Question 29

How does the rate of adverse reactions to transfusion in children compare to adults?

Answer 29

Children have slightly more reaction rates overall, especially allergic reactions.

Question 30

What are some typical RBC transfusion thresholds in children?

Answer 30

<7g/dL in general
<8g/dL perioperative or on chemo
Hct < 35% on ECMO or with severe pulm dz

Question 31

What are some typical PLT transfusion thresholds in children and neonates?

Answer 31

<25k for neonates (even higher if VLBW/ELBW)

<80k for bypass and ECMO

Question 32

Neonatal purpura fulminans

Answer 32

Thrombotic disorder with skin necrosis caused by congenital factor C/S deficiency. Treat with plasma ASAP.

Question 33

What effect does use of INTERCEPT technology have on phototherapy?

Answer 33

None; the psoralen should be fully removed and even if not the wavelengths are non-overlapping.

Question 34

What are the consequences of underdeveloped immune response in neonatal transfusion?

Answer 34

Less likely to form red cell antibodies

Less able to tolerate CMV transmission, TA-GVHD.

Question 35

What are the consequences of small neonatal blood volumes in transfusion?

Answer 35

Transfusions are relatively large; be mindful of minor incompatibility, of storage lesions, and of phlebotomy. Use aliquots.