Venous Thrombosis Flashcards
Virchow’s Triad
Stasis of Blood Flow
Endothelial Injury
Hypercoagulability
4 inherited deficiencies
Antithrombin
Protein C
Protein S
Factor V Leiden
Acquired Risk Factors of Venous Thrombosis
Age Obesity Immobilisation Surgery Long Distance Travel Malignancy Pregnancy, COCP, HRT Antiphospholipid syndrome Polycythaemia Thrombocythaemia
3 Inherited mutations
Prothrombin G20210A
Lupus Anticoagulant
Coag Excess - VIII (10%), II (2%), fibrinogen
DVT Prophylaxis
Daily Sub Cut LMWH
TED Stockings
Treatment of DVT/PE
LMWH (175 units/kg) and Warfarin
Rivaroxaban
Stopped once INR in therapeutic range 2.5
1st VTE with known cause
3 months Warfarin
Cancer VTE
3-6 months LMWH
1st VTE unknown cause
3-6 months Warfarin
Possibly lifelong
1st VTE in thrombophilic patient
3 months warfarin
Possibly Lifelong
Recurrent VTE
Lifelong Warfarin
Heparin mode of action
Potentiates antithrombin III
Inactivates thrombin and factors 9, 10, 11
When should LMWH be monitored?
Pregnancy
Renal failure
What must be monitored in Unfractionated heparin
APTT
Antidote to heparin
Protamine suplhate
Side effects of heparin
Bleeding
Heparin induced thrombocytopenia
Osteoporosis
Wafarin mode of action
Inhibits reductase enzyme responsible for regenerating active form of vitamin K.
Inhibits synthesis of factors 2, 7, 9, 10, Proteins C, S, Z
Antidote to warfarin
IV Vitamin K/ Factor concentrates
Target INR for 1st episode DVT or AF
2.5
Target INR for recurrent DVT or mechanical valve
3.5
INR 5-8
No Bleeding
Withold few doses
Reduce maintenance
Restart when INR
INR 5-8
Minor Bleeding
Stop Warfarin
Vit K slow IV
Restart when INR
> 8 No/Minor Bleeding
Stop warfarin
Give Vitamin K
Check INR Daily
Majot Bleeding (including intercranial haemorrhage)
Stop Warfarin
Give prothrombin complex concentrate
If PTCC is unavailable give FFP
Give VItamin K IV