Haemostasis Misc Flashcards
What is antithrombin?
Small plasma protein predominantly found as alpha antithrombin. Inactivates several enzymes of clotting cascade
What is plasminogen?
Inactive precursor to plasmin circulating in blood- bound in platelet plugs.
How is plasminogen kept inactive in clots?
Alpha 2 antiplasmin
What is tPA?
Tissue plasminogen activator. Released from normal endothelial cells. Suppressed at injury sites- prevents pathological clot extension.
What catalyses plasmin formation?
tPA released from normal endothelial cells
What is D dimer?
Product of fibrin breakdown. Measured in patients with suspected thrombotic disorders.
What is vitamin K?
A group of compounds necessary for full effectiveness of VII, IX, X. Allows factors to bind calcium.
What are the risk factors for vitamin K deficiency?
Liver disease, poor diet, antibiotics
What can vitamin K be used for?
Warfarin or coumarin poisoning
How does heparin work?
Binds to and increases activity of antithrombin
How is heparin given?
Subcut or IM
How does warfarin work?
Interferes with hepatic synthesis of vitamin K dependent factors especially IX and X
What is dabigatran?
DOAC. Direct thrombin inhibitor. Can be reversed.
What is the other type of DOAC?
Factor Xa inhibitors. Can’t be reversed easily
Pros and cons of DOACs?
Less serious side effects. Expensive. Work quickly.
