Venous Thromboembolism Flashcards
virchow’s triad
venous stasis
venous endothelial injury
hyper-coagulability
gold standard for diagnosis VTE. Only test that can detect proximal and distal
venography
this test is only sensitive for proximal DVT. It is non-invasive and measures blood flow following occlusion
impedance plethysmography
this test is non-invasive and measures the rate of blood flow from the reflection of sound waves off RBCs
doppler U/S
combines doppler with real time B-mode U/S to give better sensitivity and specificity of detecting proximal DVTs
duplex U/S
this test has high sensitivity but low specificity. You can rule out DVT if normal, but cant rule-in if elevated
d-dimer
If non-invasive tests are negative and you suspect a PE, what should you do?
V/Q scan
objectives for DVT treatment
prevent development of PE
prevent postphlebitic syndrome
reduce mortality
minimize adverse events and costs
this drug blocks the synthesis of thromboxane A2 from arachidonic acid by inhibiting cyclooxygenase
aspirin
ADRs include bronchospasm and GI hemorrhage
aspirin
contraindications include children under 12, breast feeding, hemophilia, PUD, and known hypersensitivity rxn
aspirin
this drug is combined with aspirin to make aggrenox
dipyrdamole
this drug causes inhibition of phosphodiesterase that hydrolyzes cAMP. Increase in cAMP causes decreases tA2 synthesis and thus platelet aggregation
dipyrdamole
used to prevent thrombosis
aggrenox
used with prosthetic mechanical valves in combo with warfarin and is an alternative to exercise in thallium myocardial perfusion imaging
dipyrdamole
ADRs- HA, GI bleed, hypotension
dipyrdamole
caution in pts with hypotension and in pts with serious CAD
dipyrdamole
this drug block ADP-induced platelet-fibrinogen and platelet-platelet binding
ticlopidine
indicated for prevention of repeat stroke or TIA and in coronary artery stinting
ticlopidine
contraindicated in pts with severe liver dysfunction, thrombocytopenia, neutropenia, PUD, and internal bleeding
ticlopidine
interacts with cimetidine, digoxin, theophylline, and red clover
ticlopidine
ADRs include bleeding, N/V/D, thrombocytopenia, neutropenia, pancytopenia, nephrotic syndrome, and dark colored urine
ticlopidine
this drug inhibits activation of glycoprotein IIb/IIIa receptor on the surface of platelets, which is required for aggregation to occur
clopidogrel
indicated for secondary prevention of CV and cerebrovascular events and in patients allergic to aspirin
clopidogrel
ADRs include hemorrhage, abdominal discomfort, and N/V
clopidogrel
this drug is safer than ticlopidine and is often added to ASA to obtain better platelet inhibition
clopidogrel
an antibody fragment directed toward the GP IIb/IIIa receptor of platelets. Binding and blocking the receptor prevents platelet aggregation
abciximab
indicated to prevent ischemic cardiac complications in patients undergoing percutaneous coronary intervention. Short term prevention of MI in patients with unstable angina
abciximab
these two drugs work like abciximab but are peptide fragments. They are potentially antigenic and should only be used once
tirofiban and eptifbatide
work by inhibiting the action of coagulation factors or interfere with the synthesis of coagulation factors
anticoagulants
binds to antithrombin III and accelerates inactivation of coag factors. AT III is an anticoagulant (inhibits binding of fibrinogen to thrombin)
heparin
binds to thrombin, inactivating its activity
heparin
binds and inhibits factor Xa (which converts prothrombin to thrombin)
heparin
this drug complexes with antithrombin III and inactivates factor Xa but does not bind as well to thrombin
LMWH
indicated for DVT, PE. Coronary artery pr-thrombosis after thrombolytic therapy
heparin
can be used in pregnancy- does not cross placenta
heparin
indicated for DVT/PE, unstable angina, and MI
LMWH
in order to treat someone with this, make sure they have a stable proximal DVT or PE, normal vital signs, low bleeding risk, no renal insufficiency, and monitoring system
heparin and LMWH
contraindicated in hemophilia, thrombocytopenia, PUD
heparin/LMWH
ADRs: bleeding (esp in those >70, recent surgery or trauma, use of ASA or NSAIDs, and renal failure)
heparin/LMWH
antidote for heparin (and sort of for LMWH)
protamine
this can occur in 3% of UFH treated patients. It is associated with arterial or venous thrombosis and causes a drop in platelet count >50%
heparin induced thrombocytopenia (HIT)
complications of this include DVT, PE, MI, stroke, TIA, and end organ damage
HIT
treat HIT
D/C UFH
use DTIs (argotroban or lepirudin)
initiate warfarin once platelets are okay
ADR includes osteoporosis
heparin (less with LMWH)
monitor: baseline aPTT, PT/INR, and CBC along with signs and symptoms of bleeding
heparin
monitor: aPTT, PT/INR, CBC, and SrCr along with anti factor Xa activity
LMWH
this drug prevents DVT following orthopedic surgery. It requires cofactor of antithrombin III for activity
fondaparinux
this drug is indicated in prevention of DVT in patients undergoing knee or hip replacement. Also used in stroke and systemic embolism prophylaxis in patients with non-valvular afib
rivaroxaban
indicated for DVT prophylaxis in patients post hip and knee replacement- dont give if CrCl <15 or severe liver failure
apixaban
reduce the risk of stroke and systemic embolism in patients with non-valvular atrial fib. Can inhibit both free and clot-bound thrombin
dabigatran
binds selectively and reversibly to the catalytic site of thrombin as a competitive inhibitor- can inhibit clot-bound thrombin
argatroban
short half life. Used in heparin induced thrombocytopenia with and without thrombosis, ischemic stroke, hemodialysis, PCI. NO antidote
argatroban
derived from the leech, these two drugs inactivate thrombin
desirudin and lepirudin
indicated in patients with heparin induced thrombocytopenia. Prophylaxis of DVT in patients undergoing hip and knee replacement
hirudins
contraindicated in active bleeding and renal or hepatic impairment
hirudins
ADRs hemorrhage and hypersensitivity
hirudins
vitamin K antagonist. Blocks the reduction of vitamin K epoxide (necessary for clotting factors II, VII, IX, X)
warfain
half life for clotting factors
II- 60 hours
VII- 6 hours
IX- 24 hours
X- 40 hours
used in acute MI, DVT, PE, afib, rheumatic disease, prosthetic heart valves, hip or knee replacement patients
warfarin
contraindicated in central thrombosis, peptic ulcer, pregnancy
warfarin
ADRs- bleeding and skin necrosis
warfarin
treat bleeding induced by warfarin
vitamin K
monitor PT/INR, aPTT, CBC, LFTs
UA and fecal occult
signs and symptoms of bleeding
warfarin
this class turns plasminogen into plasmin, which cleaves fibrin and lyses thrombi
thrombolytic agents
someone had an MI how do you administer throbolytic agent
intracoronary
used in acute MI, massive or submassive PE, heparin tx failures, extensive proximal DVT
thrombolytic agents
ADRs include hemorrhage and reperfusion arrhythmias
thrombolytic agents
contraindicated in recent surgery, CVA within 2 months, recent needle puncture, active bleeding, uncontrolled HTN, malignancy, pregnancy, CPR
thrombolytic
enzyme that catalyzes the conversion of tissue plasminogen to plasmin in the presence of fibrin. Fibrin specifically produces local fibrinolysis in the area of a recent clot with limited systemic proteolysis
alteplase
indicated for acute MI, PE, acute ischemic stroke
alteplase
ADRs include bleeding, arrhythmias, N/V, cardiac arrest, stroke, thromboembolism
alteplase
this drug forms a complex with plasminogen to convert the active enzyme plasmin, hydrolyzes fibrin plugs, and catalyzes the degradation of fibrinogen 7 clotting factors V and VII
streptokinase
indicated for life threatening DVT, PE, arterial thromboembolism, and acute MI
streptokinase
ADRs include N/V, bleeding, and antigenic reactions (allergic)
streptokinase
DVT/PE prevention: total hip replacement
LMWH, warfarin, factor Xa inh
DVT/PE prevention: total knee replacement
LMWH, warfarin, factor Xa inh, +/-IPC
DVT/PE prevention: hip fracture surgery
factor Xa inh, LMWH, warfarin, LDUH
DVT/PE prevention: trauma
LMWH, IPC or ES in LMWH C/I
DVT/PE prevention: general med (CHF, COPD) or bedrest and >1 RF
LDUH, LMWH, fondaparinux
