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
