Anticoag VTE Flashcards
Pathogenesis of Thrombosis
Describe Virchow’s Triad
1) Abnormal Blood Flow
2) Endothelial Injury
3) Hypercoagulability
What can cause endothelial injury?
How does this predispose to thrombus formation?
-Shear stress due to HTN
-HLD
-Elevated blood glucose in diabetes
-traumatic vascular injury
-some infections
1) Platelet activators like collagen promoting platelet adhesion
2) Exposure of tissue factor initiates coag cascade
3)Depletion of natural antithrombotics(t-PA) at site of injury occurs due to fractured endothelial lining
Abnormal blood flow:
Name 2 examples
How does this promote thrombosis formation?
1) Atherosclerotic lesions
2) Bifurcation of vessels
Absence of laminar flow allows platelets to flow close to vessel wall
-stasis inhibits flow of fresh blood into region preventing dilution of activated clotting factors
Hypercoagulability
Name 2 Primary Genetic Disorders
Name 2 secondary (acquired) disorders
1) Mutation in gene encoding factor V (Leiden Mutation)
2) Prothrombin G20210A mutation leads to 30% incr in circulating thrombin levels
1) Heparin exposure leading to heparin :PF4 complex
2) Immune system generates circulating Ab’s to clear platelets that have the heparin:PF4 co plex
Name Primary Hypercoagulable Conditions (7)
-Antithrombin (ATIII) deficiency
* Protein C deficiency
* Protein S deficiency
* Factor V Leiden
* Elevated factor VIII levels
* Factor XII deficiency
* Prothrombin G20210A
mutation
Name Secondary Hypercoagulable Conditions (7)
-Pregnancy
* Immobility
* Trauma
* Oral contraceptives
* Antiphospholipid syndrome
* Malignancy
* HITTS
Who is at higher risk for developing VTE? (4)
trauma, multiple surgeries of lower extremities, metastatic cancer, previous history of VTE
Risk Factors for VTE (DVT/PE)
(12)
- Age
- Previous VTE
- Surgery (hip / knee
replacement) - Trauma
- Immobility
- Malignancy
- Pregnancy
- Oral contraceptives /
hormone replacement
therapy - Hypercoagulable state
- Indwelling venous
catheter - Acute major illness
- Obesity
Signs and Sx’s of a DVT?
1) What kind of leg swelling?
2) Pain located where and when foot is doing what?
3) ____ in superficial veins
1) Unilateral leg swelling (warmth, tenderness, discoloration)
2) behind knee or calf when foot is flexed (+ Homan’s sign)
3) Palpable cord
What’s signs and sx’s of PE?
List the major ones first (5)
(D,C,C,T,T)
-Dyspnea
-Tachypnea
-Chest pain
-Chest tightness
-Tachycardia
-Diaphoretic
* Cough
* Dizziness
-Hemoptysis
* Palpitations
* Light-headedness
How to diagnose DVT?
-Clinical suspicion based on?
-Compression Ultrasound
Doppler =
B Mode =?
-Elevated ????
-Venography
-Wells score of?
risk factors
sound, visual
D Dimer (Normal is <= 240 ng/mL)
> =2 points
How to diagnose PE:
What kind of Scan? If mismatch this means high probablity of?
What kind of CT?
Elevated What?
What kind of angiogram?
Simplified Wells PE score that is ?
Ventilation/Perfusion (V/Q) scan which is less invasive.
-If mismatch, PE
SPIRAL
D-dimer
Pulmonary angiogram (contrast, expensive)
> 4 points
Risk factors for major bleeding while taking anticoag therapy
-Higher anticoagulation intensity
* Initiation of therapy (first few
days and weeks)
* Unstable anticoagulation
response
* Age > 65 years old
* Concurrent aspirin or other
antiplatelet therapy
* Concurrent NSAID use
* History of GI bleeding
* Recent surgery or trauma
* High risk for fall / trauma
* Heavy alcohol use
* Renal failure
* Cerebrovascular disease
* Malignancy
Fibrinolytic Drugs
-Used to ?
-Has the potential to dissolve not only pathologic thrombi but also ___ which could lead to ?
1) Lyse already formed clots, and thereby to restore the patency of an obstructed vessel
2) physiologically appropriate fibrin clots, which could lead to hemorrhage of varying severity
Indications for Fibrinolytic Drugs : (3)
1) Massive ileo-femoral DVT at risk for limb gangrene due to venous occlusion
2) Hemodynamically unstable PE patients (ie. SBP < 90 mm Hg, shock)
3) Select high-risk PE patients without hypotension or shock providing the risk of
bleeding is acceptable (gray-area)
What are some factors associated with high risk for adverse PE outcomes? (4)
1) Ill appearing patients with marked dyspnea, anxiety and low oxygen saturation
2) Elevated cardiac troponin levels
3) right ventricular dysfunction on echocardiography
4) right ventricular enlargement on chest CT
CI’s for Fibrinolytic Drugs
Memorize this list
-Active internal bleeding (not including menses)
* Previous intracranial hemorrhage (ICH) at any time
* Ischemic stroke within 3 months (except ischemic stroke within 4.5 hours)
* Known malignant intracranial cancer (primary or metastatic)
* Known structural vascular lesion (e.g., arteriovenous malformation, AVM)
* Suspected aortic dissection
* Significant closed head or facial trauma within 3 months
* Intracranial or intraspinal surgery within 2 months
* Severe uncontrolled hypertension (unresponsive to emergency therapy)
* For streptokinase, prior streptokinase treatment within the previous 6
months
Before fibrinolytic therapy begins, administer what?
For High Intensity Heparin
-use which weight?
Loading dose?
Maintenance dose?
During fibrinolytic therapy, either __ or ___ for duration of fibrinolytic administration
IV heparin in full therapeutic Doses
-Actual body weight
-LD : 80 units/kg bolus IV x 1 (max initial bolus = 10k units)
-MD : 18 units/kg/hr continuous IV (max initial rate = 2150 units/hr)
continue, suspend heparin
For Fibrinolytic Drugs and Dosing, Refer to Printout
Kim Printout
Initial Acute Phase Tx (Days 0-7)
-What options can you use? (4)
1) UFH IV or SC
2) SC LMWH
3) SC FONDAPARINUX
4) Oral Rivaroxaban or apixaban
If you use oral dabigatran or edoxaban , what do they require?
5-10 days of parenteral therapy first
