Hereditary and Acquired Thrombotic Disorders

Question 1

What is Virchow’s Triad?

Answer 1

1. Decreased blood flow (venous stasis)
2. Inflammation of or near the blood vessels (altered vessels)
3. Intrinsic alterations in the nature of the blood itself (altered coagulability)

Question 2

In clotting, what is more important on the arterial side? Venous side?

Answer 2

arterial = platelets
venous = fibrin

Question 3

What does VTE stand for?

Answer 3

venous thromboembolism

Question 4

Name some risk factors for venous thrombosis.

Answer 4

1. trauma
2. post-surgery
3. immobility/inactivity
4. obesity
5. pregnancy
6. estrogens/birth control
7. malignancy
8. age

Question 5

Name 5 inherited hypercoaguable disorders.

Answer 5

1. factor V Leiden
2. Prothrombin G20210A
3. Protein C Deficiency
4. Protein S Deficiency
5. Antithrombin Deficiency

Question 6

What are the 2 venous thrombosis clinical manifestations and how are they different?

Answer 6

1. DVT (extremities, swelling, redness/dusky, warmth)

2. PE (SOB, diminished exercise activity, chest pain, syncope, cardiac arrest, death)

Question 7

What is the D-dimer assay?

Answer 7

a test for clot formation b/c d-dimers can only be formed when cross-linked fibrin has been degraded by plasmin through fibrinolysis

Question 8

How are arterial thrombi treated?

Answer 8

heparin, a fibrinolytic agent (tPA), antiplatelet therapy (aspirin, ticlopidine, clopidogrel, glycoprotein IIb/IIIb inhibitors)

Question 9

How are venous emboli treated?

Answer 9

inhibit coagulation (Heparin, warfarin/Coumadin)

Question 10

What is D-dimer?

Answer 10

the breakdown product of fibrinolysis

Question 11

When can D-dimer be high, aside from clot breakdown?

Answer 11

CA, inflammation

Question 12

If D-dimer is positive, what is the next test for venous thrombosis diagnosis?

Answer 12

limbs = imaging- ultrasound w/- Doppler
lungs = CT scan, VQ scan

Question 13

What is Antithrombin Deficiency?

Answer 13

auto dominant antithrombin III deficiency, which inactivates thrombin and factors Xa, IXa, XIa, and XIIa. Treat with anticoagulation only if symptomatic or pregnancy/surgery.

Question 14

What is the tx for an acute clot?

Answer 14

heparin

Question 15

What is used to prevent additional clots?

Answer 15

warfarin

Question 16

What is Protein S Deficiency?

Answer 16

auto dominant deficiency of a vitamin-K dependent plasma protein that facilitates anticoagulant activity of protein C

Question 17

How do Protein C or S deficient pts present?

Answer 17

• VTE or with arterial thrombosis, including stroke
• Neonatal purpura fulminans
• warfarin-induced skin necrosis

Question 18

What is Protein C Deficiency?

Answer 18

an auto dominant deficiency of a vitamin-K dependent plasma protein that inactivates factors Va and VIIIa to inhibit coagulation

Question 19

What is neonatal purpura fulminans?

Answer 19

an often fatal disease associated with extensive venous or arterial thrombosis at birth and levels of protein C <5% of normal

Question 20

What is Prothrombin G20210A?

Answer 20

the second most common inherited predisposition to hypercoagulability; autosomal dominant; leads to elevated concentrations of plasma prothrombin

Question 21

How is warfarin administered?

Answer 21

orally

Question 22

What is Factor V Leiden?

Answer 22

autosomal dominant mutation of the factor V gene that causes proteolytic cleavage of protein C

Question 23

How do antithrombin III deficient pts present?

Answer 23

with venous thrombosis btw puberty and age 50

Question 24

____ Protein C deficient pts do not survive.

Answer 24

Homozygous

Question 25

What is the cofactor for protein C?

Answer 25

protein S

Question 26

Protein S binds largely to ___ in the plasma; only 40% is free and functional.

Answer 26

C4b-binding protein