Unit 12: Hematologic Flashcards
(41 cards)
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
