DVT

Question 1

What is a DVT?

Answer 1

Formation of a thrombus within the deep veins (most commonly calf or thigh)

Question 2

What describes the 3 broad factors leading to thrombus formation?

Answer 2

Virchows triad:
Venous stasis
Vessel wall injury
Blood hypercoagulability.

Question 3

Based on Virchows triad, list risk factors for DVT

Answer 3

Venous stasis:
Prolonged immobility
Vessel wall injury:
Trauma
Surgery
Blood hypercoagulability.

Question 4

Describe the epidemiology of DVT

Answer 4

Common, esp in hospitalised pts

Question 5

Describe the symptoms in DVT

Answer 5

Asymptomatic or lower limb swelling/ tenderness.

Question 6

What signs may a DVT present with?

Answer 6

Swelling, erythema, warmth
Calf tenderness
Severe leg oedema + cyanosis
Signs of PE on resp exam (fever, tachycardia, pleuritic chest pain)

Question 7

What scoring system is used to asses risk of DVT?

Answer 7

Wells

>,2 = Likely DVT

Question 8

What is the gold standard investigation for DVT?

Answer 8

Doppler ultrasound

Good sensitivity for femoral veins; less sensitive for calf veins

Question 9

What bloods should be ordered in suspected DVT?

Answer 9

D-dimer: sensitive but very non-specific, only useful as a negative predictor in low-risk patients.
Thrombophilia screen if indicated (e.g. recurrent episodes)
FBC (platelet count prior to starting heparin. High RBC indicates polycythaemia)
U+E
Clotting.

Question 10

What investigations may be performed if there is suspicion of PE?

Answer 10

ECG
CXR
ABG

Question 11

Describe the acute management of DVT

Answer 11

Anticoagulation:
Start Heparin while awaiting therapeutic INR from warfarin
Below knee anticoagulation for 3 months
Above knee anticoagulation for 6 months.
Recurrent DVTs may require long-term warfarin.

Question 12

If active anticoagulation is contraindicated and/or high risk of embolisation, what intervention is appropriate?

Answer 12

IVC filter, e.g. Greenfield filter, by interventional radiology is indicated to prevent embolus to the lungs.

Question 13

Describe the preventative management of DVT

Answer 13

TED stockings
Mobilisation if possible
At-risk groups (immobilised hospital pts) should have prophylactic heparin, e.g. LMWH if no contraindications

Question 14

List 3 complications of DVT

Answer 14

PE
Damage to vein valves + chronic venous insufficiency of the lower limb (post-thrombotic syndrome)
Venous infarction (phlegmasia cerulea dolens) (rare)

Question 15

List 2 complications of the treatment of DVT

Answer 15

Heparin-induced thrombocytopaenia

Bleeding.

Question 16

What is the prognosis of DVT?

Answer 16

Depends on extent of DVT;
below-knee: lower risk of embolus
above knee: higher risk of propagation + embolisation (if large, may be fatal)

Question 17

List 9 risk factors for hypercoagulability

Answer 17

cOCP/ HRT
Obesity
Pregnancy
Trauma
Smoking
Polycythaemia
Anti-phospholipid syndrome
Thrombophilia disorders (e.g. protein C deficiency)
Active malignancy.