Coagulation Book - Cardiac Anesthesia ch 19 Flashcards
Major ligand for platelet activation
Fibrinogen
important ligand for platelet adhesion at low shear stress
vWF
important ligand for platelet aggregation at higher shear stress
vWF
Provides post feedback by activating Cofactors V and VIII
Thrombin
Accelerates cross linking of fibrinogen by activating FXIII
Thrombin
Activates Protein C, which provides neg feedback by inactivating FVa and FVIIIa
Thrombin
Inactivates FVa and FVIIIa
Proteins C and S
Inhibits initiation of extrinsic pathway
TF inhibitor
Heparin’s pH status?
strong biologic acid
negatively charged at physiologic pH
Heparin distribution is mainly in the ? (2)
intravascular space and endothelial cells
Heparin eliminated by what?
kidneys of metabolism in reticuloendothelial system
Heparin boluses can decrease what?
SVR
The CPB priming solution should contain Heparin at what concentration?
approx the same conct as patients blood stream at onset of CPB
ex priming vol of 1500ml should contain 5000units heparin
whole blood heparin concentrations sufficient for CPB
3-4 U/mL
Thrombocytopenia is defined as?
platelet count of <100,000/uL
Hirudin
thrombin inhibitor isolated from leech salivary glands
inhibits clot bound thrombin
inhibits activation of protein C
alternative to UFH
Bivalirudin
synthetic
directly inhibits thrombin by binding to its active catalytic site and its substrate recognition site
no reversal agent
alternative to UFH (for HIT pts maybe)
Argatroban
direct thrombin inhibitor
alternative to UFH (for HIT pts maybe)
After Protamine admin on bypass the ACT should be where?
no more than 10% above value before heparin admin
Rapid Protamine admin (3mg/kg in 3 min or less) can cause what?
Hypotension – decreases systemic and pulmonary pressures as well as venous return
Hypotension from rapid protamine admin treated how?
rapid fluid admin, large doeses of epiniphrine and possibly bronchodilators (inhaled)
Daily aspirin is known as what kind of therapy?
Antiplatelet therapy
to prevent thrombosis, can cause an increase in bleeding post op when taking this up to the day
Aprotinin
proteinase inhibitor
inhibits plasmin, kallikrein(reduce inflammatory response) and other serine proteases
decreases activation of hematologic system during CPB and subsequent fibrinolysis resulting in 30-40% decrease in chest tube drainage
