DIC and coagulation Flashcards
what is DIC
excessive activation of coagulation and the formation of thrombi in the microvasculature
what mechanisms trigger DIC
the release of tissue factor or other pro-coagulants into the circulation.
widespread injury to endothelial cells
both of these involve widespread release or exposure of coagulation factors hence clots are able to form and there is subsequent breakdown of the microthrombi which results in the haemorrhages to the skin
what is waterhouse-fredericksen syndrome
when the DIC reaches the adrenal glands and causes massives clots in this space
what coagulation factor does vWF carry
it carries factor 8. this means a deficiency in vWF will also cause deficiency in factor 8 this can mimic haemophilia A in a patient
what type of biological material are the coagulation factors
they are enzymes and proenzymes that get cleaved to enzymes
what does antithrombin 3 bind to
it binds to factor Xa and thrombin
what do protein C and S inhibit
they inhibit activity of factor 8a and 5a
why do we have the INR testing be different from the PT testing
we have INR being different to account for world wide differences in testing materials for this assay.
whats the pathogenesis of deep vein thrombosis
the stasis of blood leads to adhesion of neutrophils and monocytes to the vessel wall. the adhering neutrophils undergo netosis and activate factor 12. the adhered monocytes express tissue factor to activate factor 7, thereby both processes cause coagulation to occur in the veins of the leg more often.
