Hematology Flashcards
1
Q
aplastic anemia
A
- maybe autoimmune, 50% idiopathic, radiation, infeciton, toxins, drugs, inherited . = fanconi syndrome
- sxs: weakness, fatigue, palps, DOE, tinnitus, bleeding and bruising, infxns
- dx: CBC (normocytic anemia, neutropenia, thrombocytopenia), peripheral smear shows peripheral pancytopenia with marrow hypocellularity, bone marrow bx to r/o BDS
- tx: transfusion dependent with growth factors, immunosuppression (ATG stops Tcell response, cyclosporin), cure is allogenic stem cell transplant
2
Q
iron def anemia
A
- 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
3
Q
disseminated intravascular coagulation
A
- generalized activation of coag cascade → widespread fibrin formation → consumption of platelets and clotting factors → microthrombosis → increased fibrinolysis
- causes: infxn, mech tissue injury, malig, preg, consumptive coagulopathy (consumption of clotting factors 5 and 8, protein C, and low platelets), hereditary and acquired factors tip balance in favor of clotting → thrombophilic v. hypercoaguable state
- sxs: generalized hemorrhage (petechiae and ecchymoses → GI bleed, GU bleed, surg wound, mucocutaneous or venupuncture site bleed), mental status change, focal ischemia or gangrene, oliguria, renal cortical necrosis, ARDS
- dx: thrombocytopenia, FDP/D-dimer increased, fibrinogen decreased, PTT/PT prolonged, protein C decreased
- tx: supportive care, replete platelets or clotting factors if going into surg, FFP to replace coagulation factors, anticoag only if DIC shifted toward hypercoag (heparin)
- complications: thrombosis, organ fail, purpura fulminans, sepsis, bacteremia
4
Q
Von Willebrand factor def or dz
A
- platelet dysfn, impairment in synth or fn, clots take longer to form or do not form properly, bleeding takes longer to stop, autosomal dominant (type 1 most common), F=M, + Fhx, surg bleed, MC congenital bleeding disorder
- sxs: recurrent epistaxis, gingival bleeding, unusual bleeding, GI bleed, menorrhagia (hemarthrosis not typical unless severe)
- dx: PTT prolonged (corrects with mixing), PT NORMAL, + PFA-100 prolonged, vWF antigen (ELISA) low to nl with low activity, ristocetin cofactor assay, vWF multimer assay
- tx: DDAVP - releases vWF and factor 8 from storage, vWF concentrate (Humate P), avoid antiplatelet meds (ASA< NSAID, heparin), VWF protects factor 8 from degredation
5
Q
Hemophilia A (factor 8), hemophilia B (factor 9)
A
- x-linked recessive, mostly males, generally presents in infancy or early childhood
- sxs
- neonates: ICH, prolonged hemorrhage from cicumcision or heel puncture
- infancy: SQ nodular hematoma
- toddler: hemarthrosis (painful swelling aorund joint), oral mucosa bleeding, ICH (any child that sustains severe head bump or has persistent HA, lethargy, V, seizures)
- complications: retroperitoneal bleed
- dx: prolonged PTT, quant assay for individual factors, normal PT, thrombin time, and INR; CT scan URGENTLY if signs of ICH
- tx: give factor concentrates, antifibrinolytics
- hemophilia A: DDAVP SQ or intranasal (potentiates vWF and factor 8 release), gene tx for factor 8
6
Q
idiopathic thrombocytopenic purpura etiology, RF, and sxs
A
- acquired autoimmune disorder, circulating antiplatelet IgG autoantibody (produced in spleen) directed against a membrane protein which is the fibrinogen receptor (glycoprotein IIb/IIIa) → clears complexes via macrophages, destroyed in spleen → reduces life span of platelet
- reduction in number of platelets, abundant megakaryocytes in bone marrow, shortened platelet life span, MC indication for splenectomy
- sxs: acute (children <8yo) → 1-3wks after viral URI get bleeding gums, vaginal bleed, GI bleed, hematuria, epistaxis, easy bruising, petechiae, ecchymoses, NO SPLENOMEG, CNS bleed
- chronic (any age, F) → insidious, long hx of easy bruising and menorrhagia, petechiae over pressure areas, cyclic remissions and exacerbations
7
Q
idiopathic thrombocytopenic purpura dx and tx
A
- dx: no single dx test, dx of exclusion → bleeding time prolonged, thrombocytopenia, CBC shows IDA, assess bone marrow (inc large megakaryocytes without platelet budding), cap fragility increased, PT/PTT NORMAL
- tx: mild-mod → obs, avoid contact sports, elective surg, and unnecessary meds
- first line: children → IVIG; adults → high dose steroids
- second line: rituximab → clears active B-cells making abs
- splenectomy: for persistently low platelet counts despite steroid tx, requires PCV vaccine, most effective tx
- better prognosis: young age, short duration of dz
8
Q
heparin-induced thrommbocytopenia (HIT)
A
- in 3% of pts trigger immune response between platelet factor 4 and heparin - forms abs that cross-react with platelets (ab-induced process), MC thormbocytopenia in postop period (occurs 4-7 after initation of heparin prophylaxis or tx)
- sxs: occurs 4-7d after initiation of heparin prophylaxis or tx
- thrombocytopenia + 50% drop in platelets from baseline (not below 30,000 - bleeding is not common)
- venous or arterial thrombosis (activated platelets render pt hypercoag)
- dx: PT/PTT normal; check ELISA for PF4-hep - associated IgG; doppler LE to ro DVT; CBC shows thrombocytopenia
- tx: discontinue hep and heparin-coated products (avoid platelet transfusion, anticoagulate (use lepirudin or argotraban), long-term anticoag on warf, higher incidence with UFH than enoxaparin sodium (lovenox), 50% reduction in total platelet volume, surgical pts (orthopedic/cardiac) at inc risk
9
Q
sickle cell anemia
A
- 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
10
Q
B thalessemia
A
- 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
11
Q
megaloblastic anemia
A
- 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
12
Q
vit B12 deficiency
A
- 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
13
Q
folic acid deficiency
A
- 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
14
Q
glucose-6 phosphate dehydrogenase deficiency
A
- 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
15
Q
acute lymphoblastic leukemia
A
- neoplasm of early lymphocyte precursors, MC in young children <15, MC childhood cancer, peak 2-5y
- RF: initial WBC and age at dx, rate of response, cytogenetics
- sxs: anemia, neutropenia (inc risk of bact infxn), thrombocytopenia (abnl mucosal or cutaneous bleeding, splenomegaly, hepatomegaly, LAD, bone and jnt pain, CNS involvement (meningitis, seizures), testicular involvement (ALL), anterior mediastinal mass (T-cell ALL)
- dx: innunofluorescence assay (TdT +), histology shows lymphoblasts, bone marrow bx required for dx and shows myeloblasts
- labs: WBC count variable with large number of blasts (hyperleukocytosis), anemia, thrombocytopenia, granulocytopenia, electrolytes (hyperuricemia, hyperkalemia, hyperphosphatemia
- tx: most responsive to chemo, 75% achieve full remission, relapses occur but respond well, with aggressive tx, survival rates can be up to 15y or longer
- poor prognostic factors = age <2 or >9, WBC >100000 and CNS involvement
