VTE Flashcards
what are the precursor diseases related to VTE that are important to have under control
- HTN
- DM
- Dyslipidemia
- Metabolic Syndrome
this is a stationary blood clot that remains at its point of origin
thrombus
production of thrombus
thrombosis
the is a blood clot which has traveled from its point of origin to another location which occludes a vessel
embolus
this is obstruction or occlusions of a vessel by an embolus
embolism
these are agents that affect the process of thrombosis; includes both anticoagulants (affects the coagulation pathway) and anti platelet agents (affect the function of platelets)
antithrombotic agents
does the arterial or venous thrombosis result from atherosclerotic disease; acute plaque rupture initiates clotting process
arterial
what is a thrombus composed of
- fibrin
- platelets
- RBCs
does this describe the types of thrombus in arteries or veins?
lots of fibrin and platelets with some RBCs
arteries - therefore anti-platelets work best in arteries due to the high number of platelets
does this describe the types of thrombus in arteries or veins?
lots of fibrin and RBCs with some platelets
veins - therefore antiplatelet agents would not work the best in the veins due to the low number of platelets
what are the two main types of venous thromboembolism (VTE)?
deep vein thrombosis (DVT) and pulmonary embolism (PE)
this occurs in the superficial veins (either upper or lower extremity).
- lower extremity ___ is often related to varicose veins.
- may require anti-coagulant tx depending on size, location, and other patient risk factors
superficial vein thrombosis (SVT)
this is a thrombus formation, usually in the deep veins of the legs. can also have upper extremity DVT which is less common
deep vein thrombosis (DVT)
what are the two classes of DVT?
distal - confined to the veins elwoe the popliteal vein (below the knee) most common location
proximal - involves the popliteal and/or a more proximal veins (above the knee) more risk of embolism
this is a clot (embolus) that lodges into the pulmonary artery (or one of its branches), causing complete to partial obstruction of pulmonary blood flow
pulmonary embolism (PE)
list some VTE risk factors according to Virchow’s Triad
- Hypercoagulability
- drugs (estrogen, SERMs)
- malignancy
- pregnancy
- genetic abnormalities - Vascular Injury
- major orthopaedic surgery (e.g. knee and hip replacements)
- major trauma
- indwelling venous catheters (e.g. pt getting chemo and blood clot originates from the IV line) - Stasis
- major medical illness
- immobility (e.g. bedrest for at least 3 days during hospital admission)
- major surgery
extra risk factors:
- age (risk doubles with each decade after age 50)
- prior history of VTE (once you have an event, your risk will never go back to 0 - biggest risk factor)
diagnosis of DVT
signs/symptoms:
- extremity pain, tenderness, swelling, eryhtema, warmth, cyanosis/discoloration, palpable cord & Homan’s sign (if flex foot will cause pain)
clinical probability scoring tools:
- Wells DVT risk score
- D-dimer (measures amount of D-dimer protein your body makes to break down clots - high D-dimer may suggest you have a blood clot or clotting problem)
diagnosis testing
- Doppler ultrasound
diagnosis of PE
signs/symptoms:
- dyspnea (SOB), tachypnea/tachycardia, pleuritic chest pain/palpitations, cough, diaphoresis,
clinical probability scoring tools:
- Wells PE risk score
- D-dimer (measures amount of D-dimer protein your body makes to break down clots - high D-dimer may suggest you have a blood clot or clotting problem)
diagnostic testing:
- CTPA (CT scan) *main test for diagnosing PE
- V/Q scan
what is the route for Unfractionated Heparin (UFH)
sc or iv
what class do these agents fall into:
- Dalteparin (Fragmin)
- Enoxaparin (Lovenox + biosimilars)
- Tinzaparin (Innohep)
- Nadroparin (Fraxiparine)
low molecular weight heparins (LMWH)
what class of medication is Warfarin
Vitamin K antagonist
what class do these medications fall into:
- Fondaparinux (Arixtra) -> indirect
- Rivaroxaban (Xarelto) -> DOAC
- Apixiban (Eliquis) -> DOAC
- Edoxaban (Lixiana) -> DOAC
Anti Factor Xa Inhibitors
what class of medication does Dabigitran (Pradaxa), Agratroban and Bivalirudin (Angiomax) fall into
Direct Thrombin Inhibitors (DOAC)
what class of medication does Alteplase (tPA / Activate) fall into
Fibrinolytics / Thrombolytics
this lab test measures the time it takes for a clot to form when not on anticoagulant tx / measures effect of intrinsic and common pathway
Activated Partial Thromboplastic time (aPTT)
this lab test is a measure of the integrity of the extrinsic and final common pathways
Prothrombin Time (PT)
this lab test is a ratio of a patients prothrombin time (PT) to a normal control sample
International Normalized Ratio (INR)
this lab test indirectly measures the amount of LMWH in the blood by measuring its inhibition of factor Xa activity
anti-Xa levels (for LMWH)
with regards to thrombosis what are we looking for on a CBC
platelets and Hemoglobin
this lab test may be important for the dosing of some of the anticoagulant agents
SCr
this agent used for treatment of VTE potentiates the action of antithrombin III and thereby inactivates thrombin. is given SC (onset of 1-2 hr) or IV (onset within mins).
UFH
what baseline testing is needed for UFH
weight, CBC, INR and aPTT
true or false: UFH uses weight based dosing
true
true or false: UFH needs to be dose adjusted for reduced renal function
false
what should be monitored in patients on UFH
EFFICACY & BLEEDING
- aPTT (as per protocol)
- CBC/platelets q 2-3 days while on tx
ADE’s: heparin induced thrombocytopenia (drop in platelets)
true or false: UFH is safe in pregnancy
true
this agent used for treatment of VTE inhibits primarily factor Xa. it has a longer plasma half-life and has a more predictable pharmacokinetic profile. it is given SC with a peak onset of 3-5 hours
LMWH e.g. enoxaparin
true or false: LMWH uses weight based dosing
true
true or false: LMWH is safe in pregnancy
true
what baseline testing is required before initiating LMWH
weight, Scr, CBC, INR and aPTT