Hemostasis--Krafts Flashcards
Coumadin acts on the intrinsic/extrinsic pathway
extrinsic
measure w/ INR (corrected PT)
Heparin acts on the intrinsic/extrinsic pathway
intrinsic
How do you measure the function of the extrinsic pathway?
INR
(PT is old way, INR is corrected PT)
How do you measure the function of the intrinsic pathway?
PTT
PT
prothrombin time
plasma + thromboplastin
Thromboplastin
acts like TF (tissue factor)
used in PT test
What do you use in the tube when you draw coag tests?
citrate
INR
International Normalized Ratio
normalized PT
because thromboplastic is different between manufacterors, this is way to standardize across manufacterors and hospitals
INR is used to track…
Coumadin/Warfarin coagulation status
PTT
partial thromboplastin time
-“partial” refers to part of thromboplastin, just the phospholipid
PTT is used to track…
heparin therapy and coag status
You’ll catch this disease if you run a PTT…
hemophilia A/B
Thrombin Time
plasma + thrombin
**tests for fibrinogen presence
**used when PTT prolonged, used to rule out rare fibrinogen deficiency
PTT mixing study
patient plasma + pooled plasma + phospholipid
**used when PTT prolonged
if PTT corrects: missing factor
if PTT does not correct: inhibitor present
Function of Factor XIII
crosslinks fibrin
t-PA
tissue plasminogen activator
activates plasminogen –> plasmin
plasmin breaks down clot to fibrin degradation products
Fibrin Degradation Products (FDP) Assay
very sensitive
*used to rule out CLOTTING (PE, etc.)
*+ result may be any little or big clot
*- result means you are not having a pathologic thrombus
*D-dimer is subtype
GPIa binds…
collagen
GPIb binds…
vWF
GPIIIb-IIa binds…
fibrinogen
3 parts of clotting
vasoconstriction
platelet plug (1˚ hemostasis)
fibrin (2˚ hemostasis)
