Unit 12: Hematologic Flashcards
What are reversible risk factors for DVT and PE?
trauma, surgery, pregnancy, estrogen therapy, immobility, fractures, obesity
What are acquired risk factors for DVT and PE?
age >40, malignancy, h/o thrombus, HF, CVA, nephrotic syndrome, spinal cord injury, varicose veins
What are inherited factors for DVT and PE?
activated protein C resistance, antithrombin III deficiency, protein C deficiency, factor V Lieden
What is Virchow’s triad and how is it significant?
Triad is venous stasis (sluggish blood flow), vascular endothelial wall injury, and hyper coagulability (propensity for increased blood clotting). It helps to categorize most common causes and risk factors for venous thromboembolism.
What are cardioembolic causes of of CVA?
Afib, left atrial appendage, rheumatic heart disease, HF w/ LV thrombus, PFO, Myxoma, IE, DCM, Prosthetic valves
what are two major categories of CVA?
ischemic 85% and hemorrhagic 15%
what are antithrombin III, Activated protein C and activated protein S?
Natural anticoagulants–deficiencies in these can induce prothrombotic state corresponding to 5-10 fold increase in VTE risk.
How are “massive” and “submissive” PEs defined?
Massive is >50% of pulmonary vasculature, submassive is <50%
What d-dimer level indicates probably thrombosis?
> 500
What drug class is Pradaxa? How is it eliminated?
Direct Thrombin Inhibitor. 80% really eliminated. NOT CYP450, so few interactions. QUINIDINE is one, however
What drug class is Xarelto (rivaroxiban) and Eliquis (apixiban)? How are they metabolized?
Direct factor Xa inhibitor. CYP3A4.
What is the starting dose of unfractionated heparin? What is the target aPTT?
80U/kg as IV bolus then 18U/kg/hr as continuous infusion. 1.5-2.5x control
What anticoagulants produce effect through extrinsic pathway? Intrinsic?
Oral anticoagulants extrinsic, heparin intrinsic.
When does the initial prolongation of bleeding time occur w/ warfarin therapy? When does it evert full effect?
1-3 days.
8-14 days, when factor II is depleted
How does warfarin work?
Inhibits activation of clotting factors in the liver that depend on vitamin K for synthesis-II, VII, IX, and X.
What is the half life of warfarin?
36-42 hours
What is the time needed for peak plasma concentration of dabigitran (pradaxa)?
1.5-3 hours
How long after dc’ing ASA are platelets still impaired?
7-10 days
How are plavix and asa different?
asa affects COX, Plavix does not.
What is the only PPI safe to take with Plavix?
Protonix
What is first and second line therapy for DVT or PE?
Bolus of IV UFH with subsequent infusion/subcutaneous LMWHs/subcutaneous fondaparinux.
What is first and second line therapy for prophylaxis of DVT and PE in ortho patients?
First line, LMWHs or warfarin, depending on institution. Second line, UFH started preop and SCDs.
What is first and second line therapy for secondary stroke prevention (noncardioembolic ischemic stroke)?
First line, asa (or Plavix). Second line, Plavix or Aggrenox
What is first and second line therapy for cardioembolic stroke prevention (AF)?
First line, warfarin (and now paradox). Second line, asa
What is first line therapy for prevention of systemic embolism w/ patients with artificial valves?
First line, warfarin. Second, asa
Where does RBC production start?
Starts with erythropoietin which is produced by kidneys
What do reticulocytes in peripheral blood indicate?
RBC production is being stimulated
How are anemias classified?
increased destruction as in blood loss, hemolysis, sickle cell or decreased production as in ion deficiency, thalassemia, anemia of chronic disease and aplastic anemia
What are treatments for sickle cell?
hydroxurea and folic acid
What is the earliest and most sensitive indication of iron deficiency?
ferritin level <0-12g/L
What is the normal dose of iron supplementation in anemia?
2-3mg/kg/d in TID dosing
what is expected increase in hub with iron supplementation?
Increase of 0.7-1.0 g/wk-continue 3-6 months
What meds interact the most with iron?
tetracyclines and fluorquinolones
What is usual dose of Epoetin?
50-100u/kg sc or iv 3x wkly
What causes anemia of chronic disease?
chronic infection, subacute bacterial endocarditis, inflammation, TB, malignancies
What affects can iron deficiency have on pediatric patients?
impaired mental/psychomotor development
In treating anemia of chronic disease, what would indicate a good response?
increase of more than 0.5g/dL after 2 weeks
What causes aplastic anemia?
NSAIDS, sulfas, quinidine, lithium, antiprotazoals
What causes vitamin B12 deficiency?
inadequate intake, lack of intrinsic factor, H. Pylori, or malignancy.
What B12 level is indicative of deficiency?
<200
What folate level is indicative of deficiency?
<4ng/ml
