Deep Vein Thrombosis

Question 1

Define Deep Vein Thrombosis

Answer 1

Development of a blood clot (thrombosis) in the major deep vein in the leg, thigh, pelvis or abdomen -> impaired venous blood flow

Question 2

Aetiology of Deep Vein Thrombosis

Answer 2

Virchow’s: Vessel injury, stasis, clotting system activation

Trigger that causes coagulation + prolonged immobility: Malignancy | recent surgery | recent hospitalisation | recent trauma | medical illness | hormone replacement therapy + COCP therapy | May-thurner syndrome

Question 3

Risk factors for Deep Vein Thrombosis

Answer 3

Age
Pregnancy 
Synthetic oestrogens (HRT)
trauma 
Surgery 
Previous DVT
Cancer
Obesity 
Immobility 
Coagulation disorders

Question 4

Epidemiology of Deep Vein Thrombosis

Answer 4

Relatively common
2.3 of call cases of VTE is DVT
Incidence increases with age

Question 5

Symptoms of Deep Vein Thrombosis

Answer 5

Calf swelling and tenderness
Often unilateral
Mild fever

Question 6

Signs of Deep Vein Thrombosis on examination

Answer 6

Asymmetrical oedema
Prominent superficial veins
Calf warmth and erythema
Localised pain along the deep venous system
Homan’s sign: tenderness with dorsiflexion of the foot
Pratt’s sign: calf pain on palpation

Question 7

What is phlegmasia cerulea dolens

Answer 7

If there is a massive DVT -> swelling obstructs both venous outflow and arterial inflow -> PCD -> ischaemia -> chronic venous HTN in the lef -> chronic swelling, skin thickening, induration, pigmentation + ulceration

Question 8

Investigations for Deep Vein Thrombosis on presentation

Answer 8

2-level Well’s score:
1 point or more: D-dimer (unlikely)
2 or more - proximal leg vein USS within 4 hrs (after 4 hrs, D-dimer + interim DOAC anticoagulation while waiting
If USS negative, do D-dimer -> positive -> repeat 7 days later

LEFt score in pregnancy

INR + aPTT for warfarin and heparin admin
U+E = assess medications

Question 9

Management of Deep Vein Thrombosis

Answer 9

Conservative: ted stockings, physical activity, stop OCP 4 wks before surgeries

Initiation: DOACs (consider LMWH in pregnancy)

Long term: 3 months - prevent a new thrombus, stabilise the original clot and thrombolyse

Extended (unprovoked) - 3 months to indefinite
Secondary VTE prevention

Question 10

Complications of Deep Vein Thrombosis

Answer 10

Pulmonary embolism 
Bleeding in treatment 
Heparin resistance/ aPTT confounding 
Post-thrombotic syndrome
Bleeding during long-term/extended treatment 
Osteoporosis due to heparin treatment

Question 11

Prognosis of Deep Vein Thrombosis

Answer 11

Usually death from PE or major haemorrhage (anti-coagulation effect)