Thrombophilia Flashcards
What is Virchow’s Triad?
Stasis
Vessel wall injury
Hypercoagulability
What is the most common cause of inherited thrombophilia?
Factor V Leiden
What causes Factor V Leiden?
Autosomal dominant variation in factor V that causes it to inactivate more slowly, leading to more clots
Also does not assist in degredation of VIIIa and Va, causing decreased anticoagulant activity of protein C
What lab test will be associated with Factor V Leiden?
Short PTT
What are the vitamin K dependent proteins?
Factors II, VII, IX, and X
Proteins C and S
What does a prothrombin gene mutation cause?
High prothrombin and low thrombin levels
What is protein C deficiency?
Autosomal dominant condition that causes widespread venous thrombosis and skin necrosis
What is a complication of protein C?
Warfarin induced skin necrosis
How do you treat warfarin induced skin necrosis?
Stop warfarin
Start Vitamin K
Start Heparin
Give protein C concentrate or FFP
What does protein C do?
regulates FVIIIa and FVa
What are the PT/PTT values for protein C deficiency?
Heterozygous- both normal
Homozygous - PT and PTT prolongation
What is the significance of being a vitamin K dependent protein?
Any disorder associated with vitamin K deficiency may result in vitamin K dependent factor deficiency (warfarin use, liver disease, malnutrition, DIC, nephrotic syndrome)
What is protein S?
Cofactor for protein C
What is the cause of protein S deficiency?
Autosomal dominant mutation or acquired via pregnancy, OCP, Sickle Cell, inflammation, nephrotic syndrome, coumadin therapy
What is the cause of antithrombin III deficiency?
Autosomal dominant mutation
What is antithrombin III?
Inactivates thrombin and IXa, Xa, XIa, XIIa
What are triggers for antithrombin III deficiency initial clinical manifestations?
Pregnancy, OCP, surgery, trauma
How much does pregnancy increase the risk of venous thromboembolism?
sixfold
What increases the risk of thrombosis in pregnancy
Age >35
C section (bc surgery)
Prolonged immobilization (bed rest)
Obesity
Previous thromboembolism
Coexistant thrombophilia
What is the mechanism of thrombosis in pregnancy?
Hemostasis/venous stasis - gravid uterus, compression of L iliac vein by R iliac artery
Trauma - c section or vag delivery
Coagulant factors - incr thrombin, fibrinogen, platelet activation, VWF, VII, VIII, C
Decr protein S and ATIII
What is the cause of antiphospholipid syndrome?
Acquired autoantibody (aPL), otherwise unknown pathogenesis. Can be 2/2 SLE, infection, autoimmune disease
What are the hallmarks of antiphospholipid syndrome?
Thrombotic events and pregnancy complications
What is Libman-sacks verrucous endocarditis related to?
Antiphospholipid syndrome
What is the treatment for DVT?
Warfarin with a 5 day heparin bridge
Pradaxa
Xarelto
Eliquis
Savaysa
