Coagulation/Anticoagulation Flashcards
What are 4 categories of coagulation agents?
- antiplatelets
- anticoagulants
- thrombolytics
- procoagulants
What are the 4 steps of hemostasis?
- vasoconstriction
- platelet plug
- clot formation
- clot dissolution
Normally, vascular endothelium provides a ____ surface. “__” “___” “___”
nonthrombogenic
- antiplatelet
- anticoagulant
- profibrinolytic
What factors are dependent on Vitamin K?
Factors 2, 7, 9, 10
Where is tissue plasminogen activator (t-PA) released from? (4)
tissue, vascular endothelium, plasma, urine (urokinase)
What does plasmin do?
digests fibrin…. pg 22
Are older or new clots easier to break?
new; weak cross-linking in fibrin
What does plasminogen become?
plasmin
How is plasmin formed?
from plasminogen being activated
What factor is antithrombin?
factor 3
What does factor 3 (antithrombin) do?
inactivates factor IIa, Xa
What medication works with factor 3 (anti-thrombin)?
HEPARIN
What is Warfarin?
Coumadin; Vitamin K antagonist
What is Coumadin?
Warfarin; Vitamin K antagonist
What factors are targeted by Warfarin?
Factors 2, 7, 9, 10
If a patient on Coumadin is bleeding do you give platelets? Why?
No, they have working platelets
Onset of Coumadin
Warfarin;
3-4 days
If a patient is on Warfarin, what lab needs to be checked pre-op?
PT/INR
For minor surgery, when should Coumadin be stopped?
1-5 days pre-op; goal is PT within 20% of baseline
What is in FFP?
coagulation factors?
When do you give FFP?
when a coumadin patient is bleeding (gives factors)
What naturally releases heparin?
mast cells & basophils
What does heparin do?
ENHANCES factor 3
Is heparin lipid soluble?
NO - don’t give oral
Does heparin cross placenta?
NO; it is SAFE
Can coumadin be given in pregnancy?
NO! teratogenic - give heparin instead
How long does the action of heparin last?
1.5-4 hours
What destroyes heparin?
heparinase (enzyme in the blood)
ACT normal is what?
80
Heparin will prolong what lab value?
ACT
What is a normal aPTT?
30-35 seconds
What is a normal aPTT in heparin therapy?
1.5-2.5 times pre-drug level
Goal ACT in vascular or non-CPB cases?
> 200-300 seconds
Goal ACT in interventional aneurysm clipping/coiling?
> 250
ECMO / CPB ACT goal?
> 400 seconds
What will reverse heparin?
Protamine or FFP
What is the dose of protamine?
1-1.5mg for each 100u of heparin
What does factor X do?
catalyzes the conversion of prothrombin to thrombin
Does protamine neutralize/reverse Lovenox?
NO, give FFP
What are the two categories of direct oral anticoagulants?
- direct thrombin (IIa) inhibitor
2. direct factor Xa inhibitor
What is a direct thrombin (IIa) inhibitor?
Dabigatran - Pradaxa
What is the reversal to Dabigatran/Pradaxa?
Idrucizumab (PRAXBIND)
What are direct factor Xa inhibitors?
- Rivaroxaban (Xarelto)
- Apixaban (Eliquis)
- Edoxaban (Savaysa)
What is PCC?
prothrombin complex concentrates
What are 3 targets of platelet supression?
- COX/TXA2 inhibition
- ADP receptor antagonism
- GP IIb/IIIa receptor antagonism
