Flashcards in Hematology Deck (136)
Why is protein so important in hematopoesis?
facilitates the making of new cells
Why is Fe and vitamin E so important in hematopoesis?
decreased retic count, decreased RBC life span
What is the expected result of a blood transfusion to your hematocrit and hgb?
a 3mL/kg will raise hct approximately 3%
a 10mL/kg will raise hgb by approximately 3g
How do you determine when an infant's Fe stores will be depleted?
BW + cord hgb (gm/dL) = % growth until Fe depletion
% growth + BW = wt at which Fe stores at birth will be gone
What is the physiologic effect of Fe deficiency?
has negative neurodevelopmental sequelae even when the infant is not quite iron deficient
When should Fe supplementation begin?
around 2 weeks of life
What is the recommended Fe dose for routine maintainence?
What is the recommended Fe dose for treatment?
What are the associated risks with Fe treatment?
damaging to the liver
What are the associated risks with blood transfusion treatment?
1) GvHD: seen in pts with primary immune deficiency (ex: Di George)
2) infection: incidence of CMV seropositivity in adult pop is 60% (doesn't mean active infx)
3) suppresses production of endogenous hematopoesis
4) transfusion related NEC
5) fluid overload
How can the risk of GvHD be limited when giving a PRBC transfusion?
irradiation of blood products
How can the risk of CMV transmission be limited when giving a PRBC transfusion?
leukocyte reduce: because the virus lives on WBCs
How can you maximize infant blood volume in order to reduce need for subsequent PRBC tx?
delayed cord clamping
How can you limit donor exposure in order to increase safety with PRBC tx?
1) quad packs, directed donor
2) autologous transfusion from the placenta
What criteria should be considered when considering transfusing an older patient?
1) pattern of growth
2) O2 requirement
5) if surgery is coming up
6) if you can't get enough good Fe in
7) active septic state causing increased RBC destruction
Where are platelets derived from?
What is the clinical range determining thrombocytopenia?
< 150k; severe is < 50k
What is the incidence of congenital thrombocytopenia?
rare; occurs frequently in sick infants (about 35%)
What is considered in the differential with the etiology of thrombocytopenia?
1) increased plt destruction
2) decreased production
What is considered early onset thrombocytopenia?
What is the differential in an ill appearing infant with a variable degree of thrombocytopenia in < 72 h of life?
1) Sepsis (bacterial, viral)
2) TORCH infx
3) Birth asphyxia
What is the differential in an well appearing infant with a mild to moderate degree of thrombocytopenia in < 72 h of life?
1) placental insufficiency (including PIH)
2) Genetic disorders
What is the differential in an well appearing infant with a severe degree of thrombocytopenia in < 72 h of life?
1) Neonatal alloimmune thrombocytopenia
2) Genetic disorders
What is the differential in an ill appearing infant in > 72 h of life?
1) Sepsis (bacterial, viral, fungal)
3) Inborn error of metabolism
What is the differential in an well appearing infant in > 72 h of life?
1) Drug induced thrombocytopenia (ex: heparin)
3) Fanconi anemia
What are the 4 steps in platelet production?
1) production of thrombopoietin Tpo
2) proliferation of megakarocyte progenitors
3) megakaryocyte maturation
4) generation and release of plt
Why is overall plt production less in neonates?
neonates have higher Tpo levels, but megakaryocytes are smaller and produce fewer plt
What is the mechanism of thrombocytpoenia with intrauterine hypoxia?
underproduction r/t lower levels than expected of Tpo
What is the mechanism of thrombocytpoenia with sepsis?
underproduction: body attempts to up regulate production but is unsuccessful