Blood Flashcards
hemoglobin
the iron containing pigment of the RBC. fxn is to carry oxygen to tissues. conjugated protein= iron containing pigment called heme & a simple protein/globin. combines readily w/ o2 in lungs & liberates that o2 to tissues in exchange for co2.
normocytic/normochromic
blood loss, bone marrow infiltrate
microcytic/hypochromic
iron deficiency, lead poisoning, thalassemia
macrocytic/normochromic
vit b12 def or folate def (megaloblastic anemia), drug rxn.
G6PD
red cell enzyme defect. a drug induced hemolytic anemia d/t def of __ enzyme in rbc. genetic transmission as x-linked recessive trait. usually present w/ hx of recent infection requiring pharm tx or other drug ingestion. most common offending drugs: asa, fava beans, sulfa drugs, & antimalarials. tx is supportive w/ transfusions sometimes necessary. the ___enzyme normally protects the rbc from oxidative damage by maintaining intracellular levels of the reducing agent NADPH. sx’s: back pain, fatigue, dark red urine, low grade fever, jaundice, pallor, tachy.
elev’d reticulocyte
fxning bone marrow
depressed reticulocyte
marrow failure (aplastic anemia)
serum haptoglobin
low levels suggest hemolysis
serum ferritin
usually low in iron def anemia. measures the level of iron stores in the liver, spleen, & bone marrow.
pernicious anemia
progressive megaloblastic macrocytic anemia resulting from lack of intrinsic factor essential for absorption of cyanocobalamin (vit b12). intrinsic factor secretion fails b/c of gastric acid mucosal atrophy. often post op w/ sm bowel or gastric surgery. onset gradual. prolong period of def before pt is sx. Sx: mucosal pallor, GI ℅ anorexia & diarrhea, glossitis (beefy red, smooth, sore tongue), peripheral neuropathies). dx critical or may result in irreversible neuro deficits. megaloblastic/macro anemia, dec’d hgb, & rbc’s, leukopenia w/ hyper segmented neutrophils, thrombocytopenia, & elev’d MCV, dec’d MCHC), retic low/nl, cobalamin level dec’d.
tx: cobalamine 1000 mcg/wk IM x4-6wk f/u 1000 mcg/month IM for life. refer: GI for endoscopy upon dx & q 5 yrs to r/o malignancy.
Thalassemia
hypochromic/microcytic anemia. heterogeneous group of d/o’s of hgb synthesis that have in common a def synthesis of 1+ polypeptide chains of the nl human hgb resulting in quantitative abnormality of hgb thus produced. most common genetic d/o worldwide. genes must be inherited from both parents to acquire dz. if 1 gene inherited- considered carrier only. Dx: cbc w/ diff (inc’d wbc & plt, dec’d MCV, MCHC, RDW), peripheral smear, hgb electrophoresis, retic inc’d, ferritin nl/inc’d, iron nl/inc’d, TIBC nl/dec’d, RDW nl/inc’d, LFT’s.
genetic counseling, prenatal screen, no tx for thal min. refer to hematology for thal maj. goal: maintain hgb >10 thru exchange transfusions q 3-5wks w/ iron chelation tx. splenectomy & bone marrow transplant may be indicated.
heterozygous state
thalassemia minor & minima (silent carrier)
homozygous state
thalassemia intermedia & major (cooley anemia)
alpha thalassemia
caused by mutation of genes from globin chain. most prevalent in SE asia & african west coast. silent carrier- no sx’s. see mild anemia & minimal red cell changes. loss of all 4 __ globin chains results in stillbirth of hydrophic fetus. microcytosis in absence of IDA, mild anemia, hgb electrophoresis nl
beta thalassemia
most prevalent in ppl in areas of italy & greece. mutation in globin chain. infant sx in 1st yr of life. will see pallor, failure to thrive, hepatosplenomegaly, & severe anemia. left untx’d frontal bossing & maxillary overgrowth will develop as result of bone marrow expansion. microcytosis (mcv 55-80), nl RDW, smear: nucleated rbc’s, aniscocytosis, poikilocytes, polychromatophilia, howell-jolly bodies), hgb electrophoresis absent or dec’d hgb A, inc’d fetal hgb.
