Hematology Flashcards Preview

Neonatal Pathophysiology > Hematology > Flashcards

Flashcards in Hematology Deck (136)
Loading flashcards...
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

When should Alloimmune Thrombocytopenia (NAIT) be considered?

in any neonate with initial plt count < 50k in an otherwise well appearing infant