DVT - deep vein thrombosis Flashcards
(20 cards)
what is a DVT
a thrombus (clot) formed in the deep venous circulation (usually legs) but can be anywhere
what is a PE (pulmonary embolism)
a thrombus (clot) that has embolised (travelled) and lodged in the pulmonary circulation
what dos distal vein thrombosis refer to
DVT of the calves
what does proximal vein thrombosis refer to
DVT of the popliteal vein or the femoral vein.
- proximal as it is closer to the heart
Thrombosis is considered to arise from
the interplay between the three factors that make up Virchow’s triad
what are the three factors that make up Virchow’s triad
Hypercoagulation
Endothelial injury
Circulatory stasis
what causes hyper coagulation
- Malignancy
- Pregnancy
- Oestrogen therapy (birth control)
- IBD
- Sepsis
- Thrombophilia (abnormal tendency to develop blood clots)
what causes endothelial injury
- Venous disorders
- Venous valvular damage (e.g. from previous DVT/PE - very strong RF)
- Trauma or surgery
- Indwelling catheters
what causes circulatory stasis
- Slowed blood blow, clotting cascade activated
- Left ventricular dysfunction
- Due to:
- Immobility or paralysis
- Venous obstruction
risk factors
- surgery (major and day)
- active malignancy
- pregnancy
- protein s and c deficiency
- smoking
- travelling
- trauma
- factor V leiden mutation
where are DVT most common
below the knee
where do DVTs form predominantly
in the venous valve pockets and other sites of assumed stasis
Symptoms
- Calf - warmth, tenderness, swelling, erythema (unilateral)
- Mild fever
Signs
- Pitting oedema
investigations
- D-dimer (blood test
- Ultrasound (US) Doppler leg scan diagnostic tes
D-dimer (blood test):
measures D-dimer concentration in blood from fibrin breaking down clots
- Used for ruling out DVT, not good for telling you if you have it
Ultrasound (US) Doppler leg scan diagnostic test -
used if patient has high D-dimer or Wells score (in which case US would be first line)
Acute management
- Anticoagulation - apixaban or rivaroxaban (DOACs) first line
- May be outpatient if patient considered low-risk
- If neither apixaban or rivaroxaban are suitable then either LMWH followed by dabigatran or edoxaban OR LMWH followed by a vitamin K antagonist (VKA, i.e. warfarin)
Secondary prevention (long-term)
- Inhibit clotting cascade, prevent clot formation (dont breakdown clots)
- Long term anticoagulation - warfarin, a DOAC or LMWH
- Treatment with a should be continued for at least 3 months
how does DVT present
Painful and swollen limb with redness and heat. Tenderness along vein. Sub acute development. No other obvious cause
