Hemodynamic Disorders III Flashcards
Where do intrisnic and extreinisic pathways merge
factor X
many of the factors need to be bound to what for max activity
phospholipid surface
what is necessary for coagulation
calcium
what is the end result of the coagulation cascade
cross-linked fibrin
Prothrombin time (PT)
extrinsic
what pathways is prolonged by warfarin
extrinsic
Partical thromboplastin time (PTT)
intrinsic
what pathway is prolonged by heparin
intrinsic
what pathway is slower
intrinsic
antithrombin III
directly inactivated serine proteases
increased by heparin
protein C
inhibits cofactors Va and VIIIa
decreases rate of clot formation
requires activation
plasmin
breaks down fibrin
protein S
enhances activity of protein C
thrombomodulin
activated by thrombin
binds to thrombin
activates protein C
tissue pathway factor inhibitor
inhibits VIIa-tissue factor complex
how is free plasmin inactivated
circulating alpha2 antiplasmin
urokinase
present in plasma
activates plasminogen
tPA
actives highest degree of activation when attached to fibrin
activates plasminogen
streptokinase
bacterial product
activates plasminogen
anticoagulants
prevent clot formation and extension
antiplatelet drugs
interfere with platelet activity
thromboytic agents
dissolve existing thrombi
what factors does heparin inhbit
thrombin
factor IXa
factor X
what is heparin produced by
basophils and mast cells
how does heparin affect already fromed clots
does not disintegrate them
how is heparin given
IV or subcutaneous injection
how is warfarin given
orally
how does warfarin work
interferes with vit K metabolism
what are the vitamin K dependent clotting factors
VII
XI
X
II
dabigatran
direct thrombin inhibitor
rivaroxaban and apixaban
direct factor Xa inhibitors
besides the K dependent clotting factos, what does warfarin affect
protein C and S
PT and PTT for low dose heparin
PT - normal
PTT- prolonged
PT and PTT for high does heparin
PT - prolonged
PTT - prolonged
PT and PTT for low dose warfarin
PT - prolonged
PTT - normal
PT and PTT for high does warfarin
PT- prolonged
PTT - prolonged
contraindication to warfarin
pregnancy
elderly
warfarin necrosis most liley to happen where
thighs, breasts ,buttocks
patients with warfarin necrosis have low levels of what
protein C
herparin-induced thrombocytopenia
antibodies to herparin bind to heparin/platelet factor 4 complex
results in endothelial injury and platelet activation which induces a prothrombotic state
heparin - induced thrombocytopenia occurs more commonly in what
unfractionated heparin than low molecular weigh heparin
bernad soulier disease
defect of platelet adhesion
problem with glycoprotein IB
glanzmann’s thrombasthenia
defect of platelet aggregation
problem with glycoproetin IIB/IIIa
thrombotic thrombocytopenic purpura
antibodies directed against von willebrand factor cleaving protease
von willebrand’s disease
defiency of von willebrand’s antigen
most common bleeding disorder
Hemophilia A
factor VIII deficiency
X-linked recessive
Hemophilia B
factor IX deficiency
X-linked recessive
Hemophilia C
more mild
factor XI deficiency
autosomal recessive
DIC
results from release of any substance into bloodstream that results in widespread activation of thrombin
what are biochemical markers of DIC
plasmin and thrombin activity
what can you use to diagnose DIC
D-DIMER
