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76 Cards in this Set
- Front
- Back
what is the incindence of DVT or PE
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1 in a 1000
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59% of VTE are attributed to what
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recent hospitialization or nursing home residence
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what percent of VTE are hospitalization for surgery
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24%
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what percent of VTE are hospitilization for illness
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22%
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what percent of VTE are nursing home residence
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13%
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how many cause of DVT per year in US
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5-20 million
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what percent of VT will propagate to proxmal venous system if left untreated
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20%
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what percent of propagated VT will embolize if left untreated
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50%
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what percent of patient diagnosed with PE can DVT be found
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80%
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what is virchows triad
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venous stasis
vein endothelial damage hypercoagulable state |
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what are the main associated risk factors for DVT
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pregnancy, obesity, smoking
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what is biggest risk factor for DVT
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prior DVT
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what factor are given one point
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age 41-60
prior history of post op DVT family history of DVT/PE leg swelling, ulcer, stasis, varicose veings MI/CHF stroke with paralysis IBD, central line, bed immobilization >12h, general anesthesia >2h |
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which factors are given 2 points
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age 61-70,
history of idiopathic or unprovoked DVT major surgery, malignancy, multiple trauma, spinal cord injury with paralysis |
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which factors are given 3 points
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age>70
prior history of PE inherited thrombophilia, acquired thrombophilia |
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most DVT are clinically what
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silent
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what are the keys to diagnosis of DVT
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high index of suspicion
thorough H and P good understanding of signs, symptoms, and etiology of DVT |
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when is homans test more specific
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in presence of edema and local temperature increases
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in what percent of DVT patients is homans sign absent
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50%
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what is diagnosis of DVT based on
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ID of predisposing factors
clinicial observation invasive and non-invasive testing |
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what physical findings are associated with DVT
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sudden swelling in one extremity
deep aching pain or tightness in calf or thigh |
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what is the clinical presentation for DVT
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variable and non-specific
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what is gold standard test for DVT
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contrast venography
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what are the invasive tests for DVT
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contrast venograpy
I-125 labeled fibrinogen scanning |
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what is non-invasive testing dependent on
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skill of technician
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what is the main non-invasive test
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doppler compression ultrasonography (duplex doppler)
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duplex doppler is widely used as what for DVT
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initial test
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when is duplex doppler considered positive for DVT
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if thrombus if visible or if any segment cannot be compressed by probe
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what are other non-invasive tests
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impedence plethysmography
MRI evaluation |
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how does impedence plethysmography work
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sphygmomanometers placed on calf and thigh
inflated to occlued venous return deflation of the thigh cuff occurs and calf cuff is used to measure pressure changes in both volume and impedence |
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how can you tell if there is an obstruction with impedence plethysmography
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emptying of calf is delayed if obstruction is present
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MRI accuracy is equal to what
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duplex doppler
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why is impedence plethysmography dangerous
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something could break off with compression
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blood tests for DVT
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D Dimer
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D-Dimer allows rapid exclusion of what percent of patients
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30%
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D-Dimer is for what patient group
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low risk
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methods of prophylaxis for DVT
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heparin, LMWH, Intermittant pneumatic compression devices, TED hose
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low risk prophylaxis
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early ambulation
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moderate risk
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1-2 risk factors
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moderate risk prophylaxis
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LDUH q12h, LMWH or SCD
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high risk
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3-4 risk factors
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high risk prophylaxis
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LDUH q8h, LMWH or SCD
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very high risk
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>4 risk factors
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very high risk propylaxis
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LMWH, warfarin, or IV heparin drip
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absolute contraindications for prophylaxis
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active bleeding, severe bleeding diathesis, or platelet count < 20K, neurosurgery, ocular surgery, intracranial bleeding in the last 10 days
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relative contraindications for prophylaxis
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mild to moderate bleeding, diathesis or platelet count btwn 20k-100K, brain metastases or recent major trauma, major abdominal surgery in last 2 days, GI or GU bleeding in the past 14 days, infective endocarditis, or malignant hypertension
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contraindications for LMWH
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renal insuffciency
avoid in obese patients |
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LMWH is not what
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reversible
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what is dose of unfractionated heparin
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5000 units sq a8h or q12h
give 1-2 hr preop |
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what is MOA of heparin
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binds to antithrombin 3 and inhibits platelet function
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what is adjusted dose heparin
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3500 sq q8h
1-2hr pre op |
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what is adjusted dose of heparin post op
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+/- 500 U to maintain 1.5-2 times the reference range of the activated partial thromboplastin time
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dose of fractionated heparin (LMWH)
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30mg sq bid
40mg sq qd 1-2 hr preop/8-12h postop |
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what is MOA of fractionated heparin
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inhibits activated factor 10a
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a LMWH derivative
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lovenox
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what should be monitored with enoxaparin
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hematocrit and platelet count
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what should be done if a patient is on levenox and platelet leves drop below 100K
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discontinue drug, admin protamine and choose an alternative anticoagulant agent
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IPC
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intermittent pneumatic compression
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TED hose
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graduated compresssion stockings
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what treatment will cover all three areas of virchows triad
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IPC with pharmacologic prophylaxis
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what are the results of TED stockings and heparin
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greater reduction in incidence of DVT compared to heparin alone
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when should warfarin/coumadin be stopped before surgery
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72hr before surgery
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what is management of chronic warfarin/coumadin use prior to surgery
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stop warfarin/coumadin 72hr before surgery
bengin heparin therapy and stop 5 hr prior to surgery |
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what should be done if LMWH is used prior to surgery
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stop 15hr prior to surgery
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what is MOA of LMWH
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inhibits activation of vitamin K thus preventing formation of vitamin K dependent clotting factors
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approved therapy for confirmed DVT
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IV infusion of 5k-10k U o heparin
then heparin infused at 800-1500 U/hr maintaining PTT at 2-2.5 times baseline level |
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when should coumadin.warfaring therapy begin
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as soon as long term plan is in place
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how long does it take warfarin/coumadin take to reach therapeutic levels
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3-5days
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coumadin/warfarin levels should be monitored how
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using PT
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what is confirmed treatment of lovenox for DVT
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day 1 SC dose lovenox 1mg/kg q12h
coumadin 5-10mg/d |
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confirmed lovenox treatment for DVT day 2 and beyond
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5 or more days lovenox until INR is at least 2 or 2 consecutive days
coumadin varies 3mo to 6mo in high risk patients |
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when must you discontinue lovenox treatment
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platelet count < 100K or 50% of baseline or 10% drop in 1st 24 hrs
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what is the risk with a drop in platelet count when on lovenox
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heparin induced thrombocytopenia
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what are the goals of treatment for DVT
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inhibition of growth of thromboemobolism
promotion of thromboembolic resolution prevention of reoccurrence |
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greenfield filter placement
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placed in IVC if there is clinical or venographic evidence of clot movement within the deep venous system
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the effects of DVT
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venous insufficiency, chronic venous statsis dermatitis, permanent calf enlargement, predisposition to recurrent superficial or deep thrombophelbitis, post phlebitic neuritis, need to use support hose indefinately
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