Pathophysiology of Coagulopathy Flashcards
What differences in solubility exist between fibrin and fibrinogen?
Fibrinogen - soluble
Fibin - not soluble
What products are created from fibrinogen cleavage by plasmin?
Fibrin monomer
Fibrinopeptide A
Fibrinopeptide B
Why does a fibrin polymer by itself not last very long?
Fibrin polymers are only bound through hydrogen bonding and so are transient in the fast moving blood
**Typically only lasts about 24 hours
What clotting factor is primarily responsible for prolonging the life of a fibrin clot?
• how so?
XIII, it creates COVALENT crosslinks between fibrin polymers
What would happen if you cut someone who had a factor 13 deficiency?
They would clot then re-bleed
What does the prothrombolytic complex consist of?
Factor Xa (enzyme) Factor V (cofactor) Ca2+
When you need to perform clotting assays should you use plasma or serum?
Plasma, serum lacks clotting factors because blood has been allowed to clot
If you have a prolonged PT only, what factors may be messed up?
PT - EXTRINSIC pathway measurement
• Factor VII
**Tissue Factor really isn’t measured because its part of the reagent that is added to perform the test
If you have a prolonged PT and PTT what factors may be messed up?
PTT and PT - INTRINSIC and EXTRINSIC measurement
• If both are messed up it must be in a pathway common to both - COMMON PATH
- Factor II
- Factor V
- Factor X
If you have a prolonged PTT only, what factors may be messed up?
PTT - INTRINSIC pathway measured
- Factor XII
- Factor XI
- Factor VIII
- Factor IX
Suppose you have a clotting factor that is severely mutated but PT and PTT are normal, what factor is this likely to be?
Factor XIII, is needed for crosslinking only but lack of XIII will not hinder initial clot formation
Suppose you have a clot, then at 5M urea and it returns to blood. What is a likely cause?
Factor XIII deficiency, clot returns to blood because Urea disrupts normal hydrogen bonding in the clot
What are the proenzymes in the coagulation cascade?
• Cofactors?
Proenzyme:
• II, VII, IX, X, IX ***Note: 1st four are all vit. K dep.
Cofactor:
• Tissue Factor, Factor VIII, factor V
T or F: people who take warfarin have fewer clotting factors.
False, people who take Warfarin have the same amount of clotting factors, they just aren’t active because they aren’t gamma carboxylated
Why is measurement of D-dimers important?
It is something that could ONLY show up in fibrin that has been previously polymerized
DON’T MAKE Dx. ON THE BASIS OF D-DIMERS
