Deep Vein Thrombosis Flashcards
def
formation of a thrombus within the deep veins (commonly calf or thigh)
aetiology
virchows triad
1 venous stasis
2 vessel wall injury
3 blood hypercoagulability
associations/risk factors
risk factors are inherited or acquired
inherited
1 factor V leiden
2 protein C or protein S deficiencies
3 prothrombin mutation
acquired 1 OCP 2 surgery 3 immobility 4 obesity 5 pregnancy 6 polycythemia 7 smoking 8 active malignancy 9 nephrotic syndrome
epi
common, especially in hospitalised patients
145/100,000PA
history
asymptomatic
lower limb swelling/tenderness
may present with signs/symptoms of PE
examination
calf swelling/tenderness
severe leg oedema
cyanosis
what is the Wells Clinical Prediction Score
gives the clinical probability of DVT
>2 - doppler
<2 - D-dimer
investigations
1 doppler USS
-good sensitivity for femoral veins
-less sensitive for calf veins
2 bloods
-D-dimers (fibrinogen degradation products)
-thrombophilia screen prior to anticoagulation
-FBC (platelet count prior to starting heparin)
what is the gold standard test for DVT diagnosis
doppler USS
what is the negative of D-dimer
very sensitive but very non-specific
only useful as a negative predictor in low risk patients
management
anticoagulation
-patients should be treated with heparin while awaiting therapeutic INR from warfarin anticoagulation
-DVT extending below knee - anticoagulation for 3months
-DVT extending above knee - anticoagulastion for 6months
prevention
-graduated compression stockings
-mobilisation
- prophylactic heparin for at risk groups (hospitalised/immobile patients)
what might recurrent DVTs require
long-term warfarin
what would be required in patients if anticoagulation is contraindicated and/or there is a high risk of embolisation
IVC filter to embolus to the lungs
complications of disease
1 PE
2 damage to veins
3 chronic venous insufficiency of lower limb (post-thrombotic syndrome)
complications of treatment
1 heparin induced thrombocytopaenia
2 bleeding
