Clotting Application Exercise - Foy Flashcards
What risk factors contribute to DVT?
Age, gender (female), immobility, obesity, presumably many others…
How should a stable venous blockage be treated?
Low molecular weight heparins
(Warfarin is too slow, t-PA too aggressive)
Name 4 conditions that can cause inappropriate clotting.
Factor V leiden
APLA
Prothrombin gene variation
Many, many protein or factor deficiencies (Protein S, AT…)
Factor V Leiden
How common is it?
What is its etiology & pathogenesis?
What is the inheritance pattern?
Factor V Leiden
Fairly common–it is the most common inherited thrombophilia and is seen in 5-6% of caucasians.
R506Q mutation which renders Factor V resistant to cleavage by protein C.
Autosomal dominant** (heterozygous patients experience milder symptoms).
What factors does antithrombin interact with?
What activates it?
Factors IIa and Xa. (slide 14 says factors IXa and XIa as well)
Heparin.
A patient presents with thrombocytopenia and schistocytes on blood smear. What is on the Ddx?
What if ADAMSTS-13 activity is reduced?
Microangiopathic hemolytic anemias: TTP, HUS, DIC.
Probably TTP then.
Recall the pentad that defines thrombotic thrombocytopenia purpura.
How is it treated?
MHA (with schistocytes), thrombocytopenia, mental status changes, fever, renal insufficiency.
Plasma exchange transfusion.
Recall Virchow’s triad.
Thrombosis occurs with the presence of endothelial injury, sluggish or static flow, and hypercoagulable state.
A patient presents with inappropriate thrombosis 7 days after an unspecified cardiac episode. Workup reveals thrombocytopenia.
What is the diagnosis? How can this be confirmed?
Heparin-Induced Thrombocytopenia; get ELISA for Hep:PF4 antigen
(recall the 4 “T”s: Thrombocytopenia, timing, thrombosis, no alTernate)
How is HIT treated?
What is its clinical presentation?
Direct thrombin inhibitors (eg bivalirudin)
Moderate thrombocytopenia, thromboses of both arterial and venous origin.
