3.6.4. Venous Thromboembolism

Question 1

Define Virchow’s Triad

Answer 1

1. Stasis 2. Hypercoagulability 3. Endovascular injury

Question 2

What can contribute to stasis?

Answer 2

-immobilization (long flight/travel) -acute illness (bed ridden) -spinal cord injury

Question 3

What can contribute to hypercoagulability?

Answer 3

-family history/genetic (mother with stroke, ATIII, protein C/S, lupus, factor V Leiden, prothrombin) -acquired (malignancy, estrogen/pregnancy, DIC)

Question 4

What can contribute to endovascular injury?

Answer 4

-recent surgery -trauma (especially in pelvis/lower extremity)

Question 5

List the most common risk factors for thromboebolism

Answer 5

1. personal history of VTE 2. familial history of VTE 3. surgery 4. active malignancy 5. COPD 6. Congestive heart failure 7. stroke with paralysis 8. varicose veins

Question 6

List the most common symptoms of DVT

Answer 6

1. can be asymptomatic 2. pain, swelling, redness in leg 3. hemoptysis, sycope, JVD, tachypnea, tachycardia

Question 7

What are the signs of DVT?

Answer 7

1. asymmetric edema, erythema, warmth, palpable cord 2. Homan’s sign: pain with dorsiflexion 3. <10% will demonstrate phelgmesia cerulea dolens, phlegmasia alba dolens (only seen with significant clots)

Question 8

What are the symptoms of PE?

Answer 8

*50% of those with DVT have asymptomatic PE* 1. can be asymptomatic 2. dyspnea, chest pain, hemoptysis, sudden death

Question 9

What are the signs of PE?

Answer 9

1. tachycardia 2. tachypnea 3. decreased breath sounds 4. pleuritic rub 5. signs of right heart dysfunction (JVD, hepatojugular reflux, tricuspid regurgitation, increased P2, hypotension)

Question 10

What are the Wells criteria for DVT?

Answer 10

1 point each for active cancer paralysis, paresis, cast bedridden > 3 days; major surgery w/in 12 weeks tenderness along deep veins calf swelling (3 cm asymmetry) asymmetric pitting edema collateral superficial veins prior DVT alternative diagnosis at least as likely as DVT - subtract 2 points high probability is 3 or greater points low is zero or negative points

Question 11

What are the Wells clinical prediction score for PE?

Answer 11

signs and symptoms of DVT: 3.0 PE as or more likely than an alternate diagnosis: 3.0 heart rate > 100 bpm: 1.5 immobilization or surgery in previous 4 weeks: 1.5 previous DVT or PE: 1.5 hemoptysis: 1.0 cancer: 1.0 total score: < 2 low PTP; 2-6 is moderate; > 6 is high dichotomized score: < or = 4 is unlikely; > 4 is likely

Question 12

How do we treat/work up a DVT/PE?

Answer 12

1. DVT and PE are treated the same
   
   1. If one has symptoms, it is highly sensitive. If no symptoms it is less than 50% sensitive
      
      1. quick
      2. non-invasive
      3. no radiation
      4. If DVT is found, will have to treat it anyway and it is the same as for PE. If DVT not found, will have to research PE
   2. To get a diagnostic V/Q, need a normal chest x-ray. Since many people have many other diseases, it is not likely sometimes
      
      1. Good one to try first
   3. CT angiography
      
      1. can look at lungs or clot; works for DVT and PE. Can see size of RV or reflux, etc. This is the method now.
         
         1. comes at the price of radiation induced malignancy

Question 13

What are our treatment medications for DVT/PE?

Answer 13

1. Direct inhibitors of Factor Xa = apixaban, rivaroxaban (“-xaban”s) (FA pg 399)
   
   1. their names have “x” and “a” - like the clotting factor they inhibit
   2. clinical indications: treatment and prophylaxis of DVT and PE (rivaroxaban), stroke prophylaxis in patients with atrial fibrillation
   3. toxicity: bleeding (no specific reversal agent available)
2. Use heparin for prevention and acute management (inpatient)
3. Use warfarin for long-term prevention of DVT recurrence (outpatient)

Question 14

What are phlegmesia albo dolens (PAD) and phlegmasia cerulae dolens (PCD)?

Answer 14

Literally translate to:

Painful (dolens) white (alba) edema (phlagmasia)

Painful blue edema

Typically, PAD is a sign of acute clotting blocking major veins leading to edema and use of superficial veins for blood flow returning to the heart

PAD may progress to PCD if the superficial veins also become clotted, leading to backpooling of blood in the arterial system (thus the red color of the leg)