FN: Thrombophilia Flashcards Preview

Final Notes > FN: Thrombophilia > Flashcards

Flashcards in FN: Thrombophilia Deck (12):
1

Definition

Coagulopathy predisposing to thrombosis, usually venous.

2


Inherited

- Factor V Leiden / APC resistance
-Prothrombin Gene Mutation
- Protein C and S Deficiency
- Antithrombin III Deficiency

3

Acquired 􏰀

􏰀
Progesterones in OCPs
Anti-phospholipid syndrome

4

Factor V Leiden / APC resistance

Protein C deactivates F5 and F8
􏰂 - ̄c protein S and thrombomodulin cofactors
􏰀 Degradation resistance present in 5% of population 􏰂 - Most don’t develop thrombosis
􏰀 Heterozygotes: 5x ↑VTE
􏰀 Homozygotes: 50x ↑ VTE

5

Prothrombin Gene Mutation

↑ prothrombin levels
􏰀 ↑ thrombosis due to ↓ fibrinolysis by thrombin-activated fibrinolysis inhibitor

6


Protein C and S Deficiency

Heterozygotes for either have ↑ risk of thrombosis. 􏰂 Skin necrosis occurs – esp. ̄c warfarin
􏰀 Heterozygotes → neonatal purpura fulminans

7

Antithrombin III Deficiency

􏰀 AT is heparin co-factor → thrombin inhibition
􏰀 Deficiency affects 1/500
􏰀 Heterozygotes have ↑↑ thrombosis risk
􏰀 Homozygosity is incompatible ̄c life

8

Anti-phospholipid syndrome description

CLOTs: venous and arterial
􏰄 Coagulation defect: ↑APTT
􏰄 Livido reticularis
􏰄 Obstetric complications: recurrent 1st
trimester abortion
􏰄 Thrombocyotpenia

9

Thrombophilia screen indications

􏰀 Arterial thrombosis

10

Investigations thrombophillia

􏰀 FBC, clotting, fibrinogen concentration
􏰀 Factor V Leiden / APC resistance
􏰀 Lupus anticoagulant and anti-cardiolipin Abs
􏰀 Assays for AT, protein C and S deficiencies
􏰀 PCR for prothrombin gene mutation

11

Thrombophilia Rx

􏰀 Rx acute thrombosis as per normal
􏰀 Anticoagulate to INR 2-3
􏰀 Consider lifelong warfarin
􏰀 If recurrence occurs on warfarin ↑INR to 3-4

12

Thrombophilia prevention􏰀

􏰀 Lifelong anticoagulation not needed if asymptomatic
􏰀 ↑VTErisk ̄cOCPorHRT
􏰀 Prophylaxis in high risk situations
􏰂 Surgery
􏰂 Pregnancy

Decks in Final Notes Class (196):