Thrombotic Disorders (complete)

Question 1

What are the components of Virchow’s triad?

Answer 1

1) Venous stasis
2) Altered vessels
3) Altered coagulability

Question 2

How does venous stasis contribute to thrombosis?

Answer 2

• Viscosity is higher
• Tendency for clotting to take place is higher
• aka decreased blood flow

Question 3

How does altered vessels contribute to thrombosis?

Answer 3

• Includes inflammation damage, mechanical injury, hypoxia

- Any of these can cause/create a clot

Question 4

How does altered coagulability contribute to thrombosis?

Answer 4

• Can be genetic causes or acquired disorders

- alterations in nature of the blood itself

Question 5

What are 3 major clinical symptoms that occur when a pt suffers from an acute iliofemoral thrombosis of the leg?

Answer 5

Aka: Phlegmasia cerulean dolens (extremely swollen, blue, painful leg)

1) Pain
2) Pitting edema
3) Warm, dusky, reddish-blue discoloration of the skin

Question 6

Describe pain in acute iliofemoral thrombosis of the leg. What is the pathophysiological reason?

Answer 6

Pain is pain

• Due to complete obstruction of venous outflow from extremity

Question 7

Describe pitting edema in acute iliofemoral thrombosis of the leg. What is the pathophysiological reason?

Answer 7

Pitting = when you press on it, it doesn’t immediately restore itself to normal

• Due to complete obstruction of venous outflow from extremity
• Fluid can’t be resorbed back into the circulation

Question 8

Describe the warm, dusky, reddish-blue discoloration of the skin in acute iliofemoral thrombosis of the leg. What is the pathophysiological reason?

Answer 8

Can be subtle — requires good light, must ask pt to stand for a few minutes to appreciate this

• Caused by enhanced superficial venous blood flow
• Due to complete obstruction of venous outflow from extremity

Question 9

What is the cause and mechanism of a thrombus occurring in the arterial circulation?

Answer 9

Cause: high shear stress

Question 10

What are the instigating factors and composition of the clot in arterial thrombosis?

Answer 10

Contributors:

• HTN, turbulent blood flow, atherosclerosis
• Abnormal vessels (e.g. cell injury, aneurysm)

Composition:
Aggregated platelets, small amounts of fibrin/RBCs (white thrombi)

Question 11

What is the cause and mechanism of a thrombus occurring in the deep vein of the leg?

Answer 11

Cause: low shear stress, sedentariness

Question 12

What are the instigating factors and composition of the clot in the deep vein of the leg?

Answer 12

Contributors:
- Stasis, right-side heart failure, OCs, trauma, increased age, malignancy (there’s a lot, go look at notes)

Composition:
- Lots of fibrin and RBCs (red thrombi)

Question 13

What are three clinical clues that suggest an inherited hypercoagulable disorder?

Answer 13

1) First thrombosis <50yo
2) Family history
3) Recurrent episodes of thrombosis
4) Thrombosis at unusual sites
5) Neonatal thrombosis
6) Thrombosis w/o apparent antecedent thrombogenic event

Question 14

Briefly describe at the molecular level the pathophysiologic reason that patients with deficiencies of antithrombin is likely to have thrombosis. What tests are used to diagnose this?

Answer 14

• Antithrombin 3 regulates coagulation => inactivates thrombin and 10a, 9a, 11a, 12a
• AD mutation

Acquired w/ this:

• DIC
• Liver disease
• Tx w/ heparin

Tests:
- Antithrombin assay

Question 15

Briefly describe at the molecular level the pathophysiologic reason that patients with deficiencies of protein C is likely to have thrombosis. What tests are used to diagnose this?

Answer 15

• A Vit-K dependent plasma protein
• when activated (APC) => inactivates 5a and 8a
• AD mutation

Tests:
- Protein C activity

Question 16

Briefly describe at the molecular level the pathophysiologic reason that patients with deficiencies of protein S is likely to have thrombosis. What tests are used to diagnose this?

Answer 16

• A Vit-K dependent plasma protein
• Facilitates anticoagulant activity of APC
• AD mutation

Tests:
- Ag assays

Question 17

Briefly describe at the molecular level the pathophysiologic reason that patients with factor V Leiden is likely to have thrombosis. What tests are used to diagnose this?

Answer 17

• B/c of AD mutation of factor 5 => partial resistance to protein C mechanism
• 5(leiden) inactivated 10x slowed than normal 5

Tests:

• Genetic tests (Factor 5 gene, PT 20210)
• Measure Factor 5

Question 18

Briefly describe at the molecular level the pathophysiologic reason that patients with the prothrombin gene mutation is likely to have thrombosis. What tests are used to diagnose this?

Answer 18

Genetic polymorphism causes increased amount of prothrombin (Factor 2)

• Mild hypercoag state
• associated w/ VENOUS thrombosis
• Most people w/ this mutation DO NOT clot

Question 19

What are three acquired disorders that are associated with recurrent venous or arterial thromboembolism?

Answer 19

1) Antiphospholipid AB syndrome
2) Myeloproliferative disorders
3) Malignancy

Question 20

Describe the clinical features and criteria for diagnosis of antiphospholipid antibody syndrome.

Answer 20

• Thrombotic or obstetric complications caused by Abs
• Venous AND arterial thrombosis
• Any vascular bed, any age, both male and female
• Related to drug exposure, infections, acute illness

In vitro prolonged PTT

Thrombocytopenia, hemolytic anemia, livedo reticularis

Question 21

What is the key factor in determining how long someone should be anticoagulated for a venous thrombosis? Describe it.

Answer 21

Is it:

• Transient
• Low/high risk
• Something more long term (cancer)
• More than one event