Clotting Disorders Flashcards
Name 3 natural anticoagulants
- Protein C
- Protein S
- Antithrombin III
What is the broad mechanism of action of heparin?
Potentiates the action of antithrombin III
What is rTPA?
Recombinant tissue plasminogen activator
Clinically how would one differentiate between a coagulation actor deficiency or inhibitor?
50/50 mixture study of patient/ normal plasma
Correction - Deficiency
No correction - presence of inhibitor
How is the action of the extrinsic coagulation cascade measured?
PT
How is the action of the intrinsic coagulation cascade measured?
APTT
Broadly, what factors are involved in the extrinsic coagulation pathway
TF – VIIa – Xa
Broadly, what factors are involved in the intrinsic coagulation pathway
IX – XII – VIIIa – Xa
Give 3 clinical differentials for patients that have both prolonged PT and APTT
- Vitamin K deficiency
- DIC
- Heparin toxicity
List the vitamin K dependent coagulation factors (6)
- Factor II
- Factor VII
- Factor IX
- Factor X
- Protein C
- Protein S
What is the diagnostic triad for bleeding disorders?
- Personal history of bleeding
- Family history of bleeding
- Supportive laboratory tests
Name the most common coagulation disorder
Von Willibrand’s disease
Outline the 3 types of Von Willibrand’s disease
- Reduced amount normal protein
- Abnormal protein
- Little or no protein
Recall the 6 vitamin K dependent factors
II, VII, IX and X as well as proteins C and S
Briefly outline how the intrinsic and extrinsic coagulation cascade pathways are activated
- Intrinsic - Contact with collagen from damaged blood vessels
- Extrinsic - Contact with tissue factor from the surface of extravascular cells
