Coagulation Tests Flashcards
Coag cascade:
What clotting factor is involved in the extrinsic pathway?
What clotting test is this monitored by?
What clotting factor is involved in the intrinsic pathway?
What clotting test is this monitored by?
Factor 7
PT - prothrombin time
8, 9, 11, 12
aPartial Thromboplastin Time
Vit K deficiency - what clotting time it prolonged in early stages of Vit K deficiency?
Early stage
Isolated Prolonged PT:
What organ, if diseased would cause this?
Liver
Isolated Prolonged aPTT:
What is lupus anticoagulant?
Lupus anticoagulant is an immunoglobulin that binds to phospholipids and proteins associated with the cell membrane.
Its name is a misnomer, as it is actually a prothrombotic antibody.
Lupus anticoagulant in living systems cause an increase in inappropriate blood clotting.
The presence of prolonged clotting times on a routine plasma test often triggers functional testing of the blood clotting function, as well as serological testing to identify common autoantibodies such as antiphospholipid antibodies. These antibodies tend to delay in-vitro coagulation in phospholipid-dependent laboratory tests such as the partial thromboplastin time.
Isolated prolonged aPTT:
What drug targets the intrinsic pathway and will therefore prolong aPTT?
What congenital intrinsic factor deficiencies are there?
50:50 mix with normal serum - if the clotting time corrects, what does this suggest?
Unfractionated heparin
Haemophilia A and B
A single factor deficiency
Prolonged PT and aPTT:
Severe Vit K deficiency and liver disease are a major cause!!!!
What drug could cause this?
What is Supratherapeutic warfarin therapy?
What emergency could be consuming factors leading to prolonged clotting times?
DOAC’s
When the warfarin therapy is too strong
DIC
