Coagulation Cascade
aPTT measures the activity of which pathway?
Intrinsic pathway
what routes can you administer heparin?
IV or SQ
very poor GI absorption because it's highly charged
What are the two components of "Dual Platelet Therapy"?
Aspirin and a Thienopyridine (Clopidogrel, Prasugrel, Ticagrelor)
How does Bivalrudin and Argatroban prevent clotting?
Blocks the activity of thrombin
How many days before surgery should a patient stop taking aspirin?
7-10 days
can restart 24 hours after adequate hemostasis is achieved
Hemophilia B affects what factor?
Factor 9
what is the best way to administer tPA?
directly at the site of the clot
Protamine
** Not to LMWH though**
How does Rivaroxaban (Xarelto) inhibit clotting?
Direct Factor Xa inhibition
What type of anesthesia is especially risky with anticoagulated patients?
regional anesthesia
test to measure fibrinolysis
D-Dimer
How long does it take for warfarin to reach therapeutic levels?
5 days
What type of testing monitors Argatroban efficacy?
ACT and aPTT
What does Heparin affect, and what subsequent factors are inhibited?
Antithrombin III
- factors 2, 9, 10
Your patient has been on systemic tPA for a clot but is now bleeding a lot. What would you give to help the bleeding?
- cryo
- platelets
What factors are dependent on vitamin K ?
2
7
9
10
What class of anticoagulants require dose adjustment in renal patients
LMWH, but also Dabigatran (Direct Thrombin inhibitor)
How do Thienopyradines work?
bind to P2Y receptors on platelet to block ADP binding
- no activation or aggregation of platelets
How does tPA work?
activates plasminogen to plasmin
What is an immediate reversal for a patient undergoing emergent surgery who is actively taking warfarin
- prothrombin complex concentrates
- procoagulants
- FFP
- Vitamin K
What activates prothrombin to trombin?
prothrombinase complex
- 10a, 5a, phospholipid, and Ca (factor 4)
what patient conditions can modify the efficacy of warfarin?
- increased age
- liver disease
- Drug/ETOH use
- green leafy vegetables
What should the ACT value be before starting cardiopulmonary bypass?
> 400
- inhibits Vitamin K Reductase
- Factors 2, 7, 9, 10
What is the antidote for Glycoproetin IIb/IIIa antagonists?
(ex Abciximab, Tirofiban, Eptifibatide)
dialysis