Anemias Flashcards
symptoms of anemia
yellowing eyes, pale/cold/yellowing skin, SOB, muscular weakness, change in stool color, fatigue, dizziness, syncope, low BP, palpitations, rapid HR, CP, angina, MI, enlarged spleen
mature RBC lifespan
120 days
time for erythrocyte development
5.5 days
when does loss of nucleus occur in erythrocyte development
between orthochronic normoblast and reticulocyte
pure red cell aplasia (erythroblastopenia)
reduced proliferation or differentiation of stem cells. occurs w autoimmune disease, thymoma, viral infections, herpes, parvovirus B19, hepatitis, lymphoproliferative, congenital
aplastic anemia
- reduced proliferation or differentiation of stem cells
- fanconi anemia (hereditary – autosomal recessive, prob w DNA repair, results in BM failure)
- anemia of renal failure (insufficient EPO)
- anemia of endocrine d/o
forms of decreased RBC production
more common than aplasia or aplastic anemia.
- megaloblastic anemia
- thalassemia (deficient globin synthesis)
- congenital dyserythropoetic anemia (specific assorted deficiencies in genes involved in RBC maturation)
- anemia of renal failure (dilutional and prob w EPO)
- anemia of prematurity (diminished EPO)
- iron deficient anemia (decreased heme)
what is the best indicator of iron deficiency anemia
ferritin (normal 100 (+/- 60), low
cause of iron deficiency anemia
almost always due to insufficient dietary intake
-infants, toddlers, preg woman, anyone w blood loss
US: 12% childbearing age women (higher in AA, mexican)
-most common cause is GI bleed in US; parasite worldwide
why is iron from meat more readily absorbed
attached to heme, more readily absorbed via heme carrier pro 1. non bound must be converted to ferrous iron before it can be taken up through divalent metal transporter 1.
how is iron stored
bound to apoferritin
ferroportin
transports iron from intestinal cell into blood stream
transferrin
binds ferric ion, transports to BM precursor to transferrin receptor. ferrous converted to hbg. tranferrin receptor and transferrin are recycled. can also deliver iron to hepatocytes to become stored as ferritin.
hepcidin
binds to and inhibits ferroportin on all cell types. regulatory hormone that fluctuates with iron status
features of hemolytic anemias
- increased lactate
- decreased haptoglobin
- increased reticulocytes
- increased bili
hemolytic anemias: intrinsic abnormalities
- premature destruction
- genetic d/o: hereditary spherocytosis, elliptocytosis, enzyme deficiencies, hemoglobinophathies (sickle cell)
- non genetic: paroxysmal noctural hemoglobinuria; bone marrow cell mutation causes loss of cell surface markers. autoimmune response ensues
hemolytic anemias: extrinsic abnormalities
anti-body related
- warm autoimmune hemolytic anemia: primarily by IgG. occurs at typical body temp, can be secondary to SLE or CLL
- cold agglutinin hemolytic anemia: IgM, excessive titer permits binding in cold (28-31), can be secondary to mycoplasma pna, mono, lymphoma, CLL, HIV
- transfusion rxn
- Rh disease
- mechanical trauma (HD, valve, malaria)
small cell anemia causes
- too little iron
- too much lead
- thalasemia
large cell anemia causes
- too little vit B12 or B9
- drug SE
normal cell size anemia, but bad development
-chronic disease, aplastic anemia, enzyme disorders, cell shape, leukemia
normal cell size anemia, but bad survival
- hemorrhage
- sickle cells
ferrous salts
SE
-Tips
-treat mild to mod iron deficiency
SE: dyspepsia, constipation, dark feces
-vitamin C helps absorption
-ferrous sulfate is least expsnsive
-ferrous salts are better than ferric salts
-SR formulationnot recommended, as iron may pass duodenum and jejunum
-pH dependent: no antacids, h2 blockers, PPI
-empty stomach: best effect, worst tolerance
-dose by salt weight not iron content
ferrous gluconate, sulfate, fumarate
iron RDA
men/post menopause: 8 mg/d women: 18 mg/d
what reduces iorn absorption
fiber, dairy, phosphastes, tea
injectable iron
- rx situations where oral iron does not work (speed, inflammation, GI bleed, chemo, deficit > 1 g)
- can be delivered simultaneously w EPO
- should only be used when clearly indicated, as anaphylaxis can occur in up to 3% of patients
iron dextran
primary choise for parenteral iron; drug allergies and ACE inhibitor use may increase anaphylaxis risk, dilution w dextrose increases pain
iron sucrose
secondary choise, safe if have dextran rxn. may reduce BP
sodium ferric gluconate
may drop BP, hypersensitivity rxn, decreased risk vs dextran. used for IDA in HD w EPO
ferumoxytol
for IDA in CKD. may reduce BP, hypersensitivity. may interfere with MRI for 3 months. serum iron and TSAT may be overestimated
overdose of iron rx
- gastric aspiration or vomiting
- lavage w iron precipitating salts
- deforoxamine (iron chelator) used for acute iron poisoning or for inherited or acquired hemochromatosis, SC or IM, IV can cause hypotension, LT use can cause neurotoxicity and increased infections
acute iron toxicity
- rare in adults
- can be fatal
- abd pain and bloody diarrhea in 30 mins
- hepatic failure w acidosis, coma, death
- prompt treatment is req to prevent severe necrotizing gastroenteritis
chronic iron toxicity
- hemochromatosis/hemosiderosis
- excess iron depositied in heart, liver, pancreas leading to organ failure and death
- may occur in pt w hemochromatosis and in pt given excessive amount of iron or mult RBC transfusions
- rx w intermittent phlebotomy
cyanocobalamin
- indication
- SE
-rx B12 deficiency. do not administer IV d/t anaphylaxis. injection site rxns. hypokalemia, sercondary iron deficiency d/t expansion of reticulocytes
hydroxocobalamin
- indication
- SE
-rx B12 deficiency. do not administer IV d/t anaphylaxis. injection site rxns. hypokalemia, sercondary iron deficiency d/t expansion of reticulocytes; cyanokit antidote for cyanide toxicity. max cumulative dose 10 g
folic acid
- indication
- SE
- B9 deficiency
- may reduce phenobarb, phenytoin, primidone, raltitrexed. tea can reduce absorption. note: can mask B12 deficiency
deoxyadenosylcobalamin
needed to convert L-methylmalonyl CoA to succinyl coA for TCA cycle. missing in b12 anemia
how does B12 deficiency cause anemia
folate cannot be converted to h2 folate, homocysteine cannot be converted to methionine. decreased generation of purines for DNA synth.
when is blood transfusion indicated
-only v low hgb status (
when to use erythropoiesis stimulating agent
-only to get patient to lowest acceptable range of Hgb, not for use in CKD unless extreme anemia (
epoetin alfa
- indication
- SE
- tips
- CKD, cancer/chemo
- HTN, thrombotic events, edema, feber, dizziness, insomnia, h/a, pruritis, rash, N/V/D, constipation, dyspepsia, arthralgia, cough, seizure
- Hgb response 2-6 weeks. d/c after 8-12 weeks.
darboepoetin alfa
- indication
- SE
- tips
CKD, cancer/chemo
- edema, HTN, hypotension, fatigue, fever, h/a, dizziness, diarrhea, constipation, N/V, muscle spasms, arthralgia, URI
- d/c if inadequate after 8 weeks.
IL-3
-stimulations colony formation of most lines
filgastrim
G-CSF
- stimulates neutrophils
- can moilize hematopoietic stem cells
sargramostim
GM-CSF
- stimulates neutrophils
- can moilize hematopoietic stem cells
oprelvekin
Il-11
-stimulates megakaryocytic progenitors and PLT
romiplostim
- thrombopoietin receptor agonists
- experimental for refractory cases of thrombocytopenia
eltrobopag
- thrombopoietin receptor agonists
- experimental for refractory cases of thrombocytopenia
hyperbaric oxygen
- allows for increased oxygen content of plasma (hgb independent)
- for use w exceptional blood loss or situations where transfusions cannot be used due to medical, practical, or religious reasons
