Deep vein thrombosis

Question 1

What is a DVT?

Answer 1

A clot that usually develops in one of the deep veins, usually occurring in the leg.

Question 2

What are the signs and symptoms of a DVT?

Answer 2

Asymptomatic.
Pain.
Oedema.
Erythema/discolouration.
Increased temperature of symptomatic leg.
Engorgement of surface veins.

Question 3

What is the differential diagnosis of DVT?

Answer 3

Musculoskeletal injury.
Baker’s cyst rupture.
Cellulitis.

Question 4

What is the treatment for DVT?

Answer 4

Anticoagulation therapy with unfractionated heparin or a low molecular weight heparin, e.g. dalteparin, and secondary management with a vitamin K antagonist, e.g. warfarin.

Question 5

What is the pathophysiology of DVT?

Answer 5

VIRCHOW’S TRIAD:
Hypercoagulability: malignancy, surgery, trauma, oral contraceptive pill, clotting abnormalities.
Venous stasis: immobility (e.g. after surgery), pregnancy, heart failure.
Trauma: inflammation, previous thrombosis.

Question 6

What are the complications of DVT?

Answer 6

Pulmonary embolism.

Post-thrombotic syndrome.

Question 7

What investigations are conducted for suspected DVT?

Answer 7

D-dimer: this is sensitive but not specific, i.e. if the result in negative then the cause is unlikely to be DVT.
B-mode venous compression ultrasonography: for DVT above the knee.
Investigations to uncover cause of DVT.
The Modified Wells Score may be used to calculate probability of DVT.