Flashcards in Hematology Deck (136)
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61
Why is protein so important in hematopoesis?
facilitates the making of new cells
62
Why is Fe and vitamin E so important in hematopoesis?
decreased retic count, decreased RBC life span
63
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
64
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
65
What is the physiologic effect of Fe deficiency?
has negative neurodevelopmental sequelae even when the infant is not quite iron deficient
66
When should Fe supplementation begin?
around 2 weeks of life
67
What is the recommended Fe dose for routine maintainence?
2-4mg/kg/day
68
What is the recommended Fe dose for treatment?
4-6mg/kg/day
69
What are the associated risks with Fe treatment?
damaging to the liver
70
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
71
How can the risk of GvHD be limited when giving a PRBC transfusion?
irradiation of blood products
72
How can the risk of CMV transmission be limited when giving a PRBC transfusion?
leukocyte reduce: because the virus lives on WBCs
irradiate
73
How can you maximize infant blood volume in order to reduce need for subsequent PRBC tx?
delayed cord clamping
74
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
75
What criteria should be considered when considering transfusing an older patient?
1) pattern of growth
2) O2 requirement
3) spells
4) retic
5) if surgery is coming up
6) if you can't get enough good Fe in
7) active septic state causing increased RBC destruction
76
Where are platelets derived from?
megakaryocytes
77
What is the clinical range determining thrombocytopenia?
< 150k; severe is < 50k
78
What is the incidence of congenital thrombocytopenia?
rare; occurs frequently in sick infants (about 35%)
79
What is considered in the differential with the etiology of thrombocytopenia?
1) increased plt destruction
2) decreased production
80
What is considered early onset thrombocytopenia?
first 72h
81
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
82
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
3) Autoimmune
83
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
3) Autoimmune
84
What is the differential in an ill appearing infant in > 72 h of life?
1) Sepsis (bacterial, viral, fungal)
2) NEC
3) Inborn error of metabolism
85
What is the differential in an well appearing infant in > 72 h of life?
1) Drug induced thrombocytopenia (ex: heparin)
2) Thrombosis
3) Fanconi anemia
86
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
87
Why is overall plt production less in neonates?
neonates have higher Tpo levels, but megakaryocytes are smaller and produce fewer plt
88
What is the mechanism of thrombocytpoenia with intrauterine hypoxia?
underproduction r/t lower levels than expected of Tpo
89
What is the mechanism of thrombocytpoenia with sepsis?
underproduction: body attempts to up regulate production but is unsuccessful
90
