Hereditary and Acquired Thrombotic Disorders Flashcards
What is Virchow’s Triad?
- Decreased blood flow (venous stasis)
- Inflammation of or near the blood vessels (altered vessels)
- Intrinsic alterations in the nature of the blood itself (altered coagulability)
In clotting, what is more important on the arterial side? Venous side?
arterial = platelets venous = fibrin
What does VTE stand for?
venous thromboembolism
Name some risk factors for venous thrombosis.
- trauma
- post-surgery
- immobility/inactivity
- obesity
- pregnancy
- estrogens/birth control
- malignancy
- age
Name 5 inherited hypercoaguable disorders.
- factor V Leiden
- Prothrombin G20210A
- Protein C Deficiency
- Protein S Deficiency
- Antithrombin Deficiency
What are the 2 venous thrombosis clinical manifestations and how are they different?
- DVT (extremities, swelling, redness/dusky, warmth)
2. PE (SOB, diminished exercise activity, chest pain, syncope, cardiac arrest, death)
What is the D-dimer assay?
a test for clot formation b/c d-dimers can only be formed when cross-linked fibrin has been degraded by plasmin through fibrinolysis
How are arterial thrombi treated?
heparin, a fibrinolytic agent (tPA), antiplatelet therapy (aspirin, ticlopidine, clopidogrel, glycoprotein IIb/IIIb inhibitors)
How are venous emboli treated?
inhibit coagulation (Heparin, warfarin/Coumadin)
What is D-dimer?
the breakdown product of fibrinolysis
When can D-dimer be high, aside from clot breakdown?
CA, inflammation
If D-dimer is positive, what is the next test for venous thrombosis diagnosis?
limbs = imaging- ultrasound w/- Doppler lungs = CT scan, VQ scan
What is Antithrombin Deficiency?
auto dominant antithrombin III deficiency, which inactivates thrombin and factors Xa, IXa, XIa, and XIIa. Treat with anticoagulation only if symptomatic or pregnancy/surgery.
What is the tx for an acute clot?
heparin
What is used to prevent additional clots?
warfarin
What is Protein S Deficiency?
auto dominant deficiency of a vitamin-K dependent plasma protein that facilitates anticoagulant activity of protein C
How do Protein C or S deficient pts present?
- VTE or with arterial thrombosis, including stroke
- Neonatal purpura fulminans
- warfarin-induced skin necrosis
What is Protein C Deficiency?
an auto dominant deficiency of a vitamin-K dependent plasma protein that inactivates factors Va and VIIIa to inhibit coagulation
What is neonatal purpura fulminans?
an often fatal disease associated with extensive venous or arterial thrombosis at birth and levels of protein C <5% of normal
What is Prothrombin G20210A?
the second most common inherited predisposition to hypercoagulability; autosomal dominant; leads to elevated concentrations of plasma prothrombin
How is warfarin administered?
orally
What is Factor V Leiden?
autosomal dominant mutation of the factor V gene that causes proteolytic cleavage of protein C
How do antithrombin III deficient pts present?
with venous thrombosis btw puberty and age 50
____ Protein C deficient pts do not survive.
Homozygous
What is the cofactor for protein C?
protein S
Protein S binds largely to ___ in the plasma; only 40% is free and functional.
C4b-binding protein
