Hematology Flashcards
HbA
alpha2, beta2
HbA2
alpha2, delta2
HbF
alpha2, gamma2
HbH
beta4 - nonfunctional
HbBarts
gamma4 - nonfunctional
What shifts oxygen dissociation curve up and to the left
HbF - holds on to it tighter
What shifts oxygen dissociation curve down to the right
acidosis, hypoxia, 2,3 DPG
Which iron can bind oxygen, which cannot
Fe2+ can bind; Fe3+ cannot bind O2
What causes Fe3+
antibiotics, anesthetics, aniline dyes, metoclopramide, rasburicase, chlorates, nitrates and bromates.
What is the Rx for methemoglobin
methylene blue
What is methylene blue contraindicated in?
G6PD
What conditions can lead to production of methemoglobin?
acute gastroenteritis (stool bicarb) loss –> acidosis, bacterial overgrowth –> nitrates
What co-exists with lead poisoning
Fe deficiency
what are findings in lead poisoning
basophilc stippling in RBC, microcytosis only with Fe deficiencies, free erythrocyte protoporphyrin
What is Hb at birth typically?
15-20 g/dl
When does anemia nadir?
2-3 months (mean 10.7)
When does nadir happen for premies?
earlier and lower nadirs
Which stores is smaller: folate or B12
folate
When can deficiency of folate be seen and how quickly can anemia develop?
1 month; anemia by 4 months
Histology of folate, B12 deficiency
hypersegmented poly
HbF and A
normal
HbFAS
sickle cell trait
HbFS
presumptive sickle cell
HbFS(little A)
sickle cell - beta thalassemia low MCV