Hematology

Question 1

vit K def

Answer 1

• rare, vit K usually comes from liver, green leafy veg, broccoli, peas, green beans, soybeans
• occurs from deficient intake of vitK, malabsorption, or decreased intestinal production by bacteria (from chemotherapy or abx)
• vit K plays role in activity of coag factors II, VII, IX, and X
• sxs: soft tissue ecchymosis, hematomas, mucosal bleeding
• dx: PT prolonged, clotting factors low
• tx: vitK via IV or PO

Question 2

polycythemia vera

Answer 2

• inc production of basophils and mast cells → itching after hot shower from hist release
• onset 50-70yo, clonal stem disorder w/ excessive proliferation of erythroid, myeloid, and mekakaryocytic progenitor cells
• spent phase: extramedullary hematopoiesis in liver and spleen w/ normocytic anemia
• sxs: elevate Hgb/Hct, full body itching w/ warm water, HTN, HA, fullness of face/head, dizziness, impaired vision, CP, claudication
• signs: splenomegaly, hepatomegaly, plethora or ruddy complexion
• dx: CBC (hyperviscosity, high RBC count, red cell mass increased, thrombosis, leukocytosis, low serum EPO, elevated B12, hyperuicemia, bone marrow bx
• tx: phlebotomy (goal = hct <45%), low dose ASA, hydroxyurea, median survival = 9-14y

Question 3

iron deficiency anemia

Answer 3

• significant def in mass of circ RBCs (O2 carrying capacity = low
• dec cell mass or Hgb conc; microcytic (MCV <80), hypochromic w/ low H/H
• sxs: fatigue, palps, SOB, weakness, HA, tinnitus
• signs: tachycardia, tachypnea on exert, pallor, glossitis, angular chelitis, pica, koilonychia, jaundice and splenomegaly
• dx: CBC (retic low, RDW = high), dec iron, ferritin, and transferrin, inc TIBC, ferritin <15 (diagnostic), check hgb and hct, periph smear → poikilocytes (pencil or cigar shaped)
• tx: oral iron TID (6wk to correct anemia, 6mo to replete iron) → Ferrous sulfate 3mg/kg once or twice daily, give between meals with juice, not milk

Question 4

sickle cell anemia

Answer 4

• mutation in B-globin gene that changes the 6th amino acid form glutamic acid to valine
• sxs: acute pain (hrs to 2wk); RF → infxn, fever, excess exercise, anxiety, abrupt change in temp, hypoxia, hypertonic dyes
• signs: TTP, fever, tachycardia, anxiety
• complications: pulm HTN, ESRD, hand foot syndrome, priapism (permanent impotence)
• dx: hemolytic anemia, reticulocytosis, granulocytosis, periph smear → elongated and crescent RBCs, target cells, nucleated RBC, Hgb electro, mass spec, sickling tests (confirms)
• tx: crisis → vigorous hydration, aggressive pain meds (morphine), nasal O2; severe sxs → hydroxyurea, pts 3+ crises/year or repeated ACS → increases production of Hgb F (cant sickle), BMT

Question 5

acute chest syndrome

Answer 5

• in situ sickling w/in lung, producing pain and temporary pulm dysfn
• sxs: CP, fever, cough
• signs: tachypnea
• dx: arterial O2 desat
• tx: monitor hydration for pulm edema, O2 tx, transfuse to Hct >30
• complicaitons: pulm HTN, cor pulmonale

Question 6

B thalassemia

Answer 6

• only 2 Bglobin genes on chrom 11, but 4 alpha genes on chrom 16 → disrupts ratio between alpha and beta chains → changes stability of Hb and causes hemolysis
• sxs: asx, mild anemia
• signs: HSM, jaundice
• dx: Hgb electrophoresis, CBC (microcytic hypochromic anemia), iron NL to increased (serum iron, ferritin, transferrin sat, normal TIBC), peripheral smear → target cells, basophilic stippling, elliptocytes
• tx: transfusion, PO iron repletion and B12 only if concomittant iron def anemia, allogenic bone marrow transp, folic acid, deferoxamine (iron chelator), splenectomy

Question 7

alpha vs beta thalassemia

Answer 7

Question 8

megaloblastic anemia

Answer 8

• MCV >100, inhib of DNA synth during RBC produciton
• dx: CBC, iron studies (NL to inc serum iron, ferritin, transferrin sat; NL to DEC TIBC), periph smear shows macrocytic megaloblastic cells

Question 9

Vit B12 deficiency

Answer 9

• vit B12 = cobalamin
• autoimmune destruciton of gastric parietal cells → atrophic gastritis → lack of intrinsic factor produciton; cofactor for 2 enzymatic rxns required for DNA synth, brain/nervous system fn, formation of RBC
• RF: chronic alc, vegetarian, celiac and crohn dz, gastric bypass surg, parasites
• MCC: pernicious anemia (lack of IF)
• sxs: anemia, sore tongue, periph neruopathy, balance probs, depression, dementia, glossitis
• signs: loss of vib touch
• dx: B12 dec, homocysteine inc, methylmalonic acid inc, hyperseg neutrophils
• tx: lifelong IM B12 → cyanocobalamin daily x1wk, weekly x1m, monthly for life

Question 10

folic acid def

Answer 10

• cofactor for DNA synth, alcs and malnourished have smaller stores, dec intake, inc requirement, sickle cell, thalassemia, sprue, crohn, drugs
• sxs: less neuro sxs, neural tube defects (spina bifida)
• dx: homocysteine inc, serum folic acid low, RBC folic acid <150 (dxic), macroovalocytes and hyperseg PMNs (pathognomonic)
• tx: po folic acid 1-5mg, avoid ETOH, green leafy veggies, yeast, legumes, fruits, animal proteins, prophylactic folic acid for preg/lactating and sickle cell

Question 11

hemolytic anemias

Answer 11

• sxs of acute/chronic anemia, dark urine, back pain
• signs: jaundice
• dx: CBC (high retic), inc iron, ferritin, transferrin sat, dec TIBC, total (indirect) bili inc, haptoglobin dec, periph smear → microcytic, normochromic anemia, spherocytes, bone marrow bx

Question 12

glucose-6 phosphate dehydrogenase def

Answer 12

• oxidant sensitive hemolytic dz (heinz bodies + bite cells → RBC destruction)
• MC seen in tropical areas prevalent for malaria (Africa, China, Mediterranean)
• hx: hemolysis only with infxn, met acidosis, and certain meds, chronic hemolytic anemia, jaundice, sx of hemolysis
• dx: periph smear: bite cells, heinz bodies
• tx: avoid potentially harmful drugs, monitor infxn, acute → blood transfusion

Question 13

hereditary spherocytosis

Answer 13

• congenital hemolytic jaundice, familial hemolytic anemia
• inherited dysfn or deficiency in one of the erythrocyte membrane proteins (spectrin, ankyrin, band 3 protein, or protein 4.2) → spherocytic erythrocytes are sequestered and destroyed in spleen; autosomal dom
• sxs: mild jaundice, mild-mod anemia, malaise, abd pain in LUQ
• signs: splenomeg
• dx: CBC, MCV dec; retic count, LDH, indirect bili, stool urobili → elevated; hgb low, EDW elevated, spherocytes on periph smear, osmotic fragility inc, coombs test neg
• tx: splenectomy, cholecystectomy if gallstones present
• complications: hypoplastic crises (follow acute viral illness → profound anemia, HA, N, abd pain, pancytopenia, hypoactive marrow, pigmented gallstones