Lec 18 - Pediatric CBC

Question 1

CBC components:

Answer 1

• RBC
• Lymphocyte
• Monocyte
• Eosinophil
• Basophil
• Neutrophil
• Platelets

Question 2

WBC range:

Answer 2

9000-30000

compared to adult - 5000 to 12000

Question 3

Neutrophil range:

Answer 3

50-60% of WBC increases after birth and then decreases then increases to adult value of 59%

Question 4

I:T ratio
what is it
how to calculate

Answer 4

immature neutrophils to total neutrophils

bands+metamyelocytes +myelocytes)/(Numerator +neutrophils

Question 5

Interpretation of I:T ratio

Answer 5

• low suspicion = 0-.15
• intermediate = .15-.2
• higher = >.2

Question 6

Lymphocyte norm in newborn?

Answer 6

~30%

Question 7

hemoglobin levels:

Answer 7

higher at birth! 14-22

Question 8

Polycythemia is based on what kind of sample: (for HCT)

Answer 8

VENOUS HCT>65%

Question 9

Capillary venous samples for polycythemia

Answer 9

values tend to run high for HCT - cant really trust this since you squeeze the blood out so not equal stuff

Question 10

polycythemia causes:

Answer 10

• increased fetal erythropoiesis
• erythrocyte transfusion
• DIABETIC MOMS

Question 11

polycythemia is a big deal bc?

Answer 11

hyperviscosity = heart failure or thrombosis

Question 12

newborns who have polycythemia symptoms and have high venous HCT get what?

Answer 12

exchange transfusion - take babies blood and exchange it with blood with saline or blood with normal HCT

Question 13

Drop in Hg levels when?

Answer 13

10-12 weeks bc start switching over to HbA from HgF
to 6-9.5 ish

-premies drop in Hb even more

THIS DROP IN Hg IS CALLED THE PHYSIOLOGICAL NADIR!!!**

Question 14

LOWER LIMIT MCV in child less than 10 years formula?

Answer 14

70fL + age in years = MCV

Question 15

UPPER LIMIT MCV after 6 mo of age formula:

Answer 15

84 + .6fL x #year up to adult 96fL

Question 16

Most important RBC indicator:

Answer 16

MCV

Question 17

MCHC might be useful in:

Answer 17

spherocytosis

Question 18

when does physiologic anemia occur in infancy? why?

Answer 18

10-12 weeks bc RBC life span is decreased at about 80 days

Question 19

Reticulocytes are: How are the they different general terms?

Answer 19

immature RBC - LARGER than mature RBC

Question 20

Three causes of thrombocytopenia in newborns

Answer 20

1) Alloimmune thrombocytopenia: transfer of maternal antibody across the placenta - marks baby platelets = platelet destruction
2) Maternal Immune thrombocytopenic purpura: mom forms antibodies against her own platelets type IgG and go into baby and destroy baby platelets - Tx IVIG to bring up moms platelets
3) Decreased platelet production from infected bone marrow - antibiotics

Question 21

Polychromatophilia definition

Answer 21

ability of bone marrow to produce reticulocytes in response to RBCloss or breakdown

Question 22

Platelets levels

Answer 22

run the same throughout age

150-450K

Question 23

physical finding for alloimmune thrombocytopenia?

to fix bleeding?

Answer 23

petechia and brusing
but serious intracranial bleeding can occur

give baby transfusion of MOMS platelets