VTE recorded lectures Dr.Weber- Part 1

Question 1

What are Venous Thrombi composed of?

Answer 1

Red blood cells, fibrin, and few platelets

Question 2

How do thromboembolisms form?

Answer 2

-Flow obstruction
-Vascular tissue wall becomes inflamed
-Thrombus occurs and affects venous blood flow OR
-emboli occur and enter pulmonary circulation

Question 3

What is Virchow’s Triad?

Answer 3

1. Abnormalities of clotting components that lead to hyper-coagulable state
2. Abnormality of surfaces in contact with blood flow that lead to endothelial injury
3. Abnormalities in blood flow which leads to circulatory stasis

Question 4

What factors activate coagulation?

Answer 4

Von Willebrand factor
Tissue factor
Factor Xa
Factor VIIa
Factor XIIa
Thrombin (Factor 2)

Question 5

What factors inhibit coagulation?

Answer 5

Heparin
Thrombomodulin
Antithrombin
Protein C
Protein S
Tissue Factor Pathway inhibitor

Question 6

Explain the coagulation cascade?

Answer 6

Think of it as 3 stages
1. Initiation
- The initiation of clot formation is caused due to damage of the blood vessel wall that exposes the endothelium to Tissue factor which activates factor X and V to allow for prothrombin to become Thrombin (just small amount)
2. Amplification
- Thrombin begins the amplification process and activates many plotting factors like V, VII, vWF, and XI
3. Propagation
- this involves collagen and thrombin activated platelets that leads to activation of factor X and V which cleave prothrombin to thrombin in large amounts. The large amounts of thrombin then cleave fibrinogen to fibrin

Question 7

What is Postthrombotic syndrome?

Answer 7

This is long term complication of DVT caused by damage to venous valves

Usually happens when patients have improper management of VTE

Question 8

What are DVT risk factors?

Answer 8

• those 40 and older
• Family history of VTE
• Heart Failure
• Immobilization for longer than 10 days
• Malignancy
• Myocardial Infarction
• Obesity
• Orthopedic injury
• Oral contraceptive/ estrogen use
• paralysis
• postoperative state (within 3 months)
• Pregnancy
• Prior DVT
• Varicose Veins

Question 9

what are the nonpharmacologic treatment options?

Answer 9

Always baseline monitoring
1. DVT
- Bed rest ( with appropriate anticoagulations on board)
- Elevation of feet
- Pain management
- Compression stockings

2. PE
   - Oxygen
   - Mechanical ventilation
   - Compression stockings

Question 10

When picking treatment what would be an ideal anticoagulant?

Answer 10

• Oral
• Once daily dosing
• quick onset
• limited monitoring
  limited or no drug interactions
• Available and effective antidote
• wide therapeutic index
• low cost

Question 11

Evolution of anticoagulation

Answer 11

1930s
- Heparin (inj)
1950s
- Warfarin (adv: oral)
1980s
- LMWH (adv: more predictable dosing)
1990s
- DTI
Xa inhibitors (adv: less monitoring needed)
2010
- DTI/Xa inhibitors (adv:oral)