Deep vein thrombosis

Question 1

Risk factors

Answer 1

Strong
medical hospitalisation within the past 2 months
major surgery within 3 months
active cancer
lower-extremity trauma
increasing age
pregnancy
obesity
factor V Leiden
prothrombin gene mutation G20210A
protein C or S deficiency
antithrombin deficiency
antiphospholipid antibody syndrome
medical comorbidity
recent long-distance air travel
use of specific drugs->OCP
nephrotic syndrome

family hx

Question 2

Signs

Answer 2

Calf warmth, swelling, tender
Mild fever
Pitting edema
Homan’s sign->should not be tested as can dislodge a clot

Question 3

History- important

Answer 3

Symptoms
Recent surgery, presence of an active cancer, lower-extremity trauma, recent hospitalisation, recent immobility, and presence of underlying chronic medical illness. Family history of venous thrombosis or PE
current pregnancy, obesity, factor V Leiden mutation, prothrombin gene mutation G20210A, protein C or S deficiency, antithrombin (AT) deficiency, antiphospholipid antibody syndrome, acute medical comorbidity (especially those associated with inflammation, infection, and immobility), recent long-distance air travel, and use of certain drugs including oestrogen- or third-generation progestogen-containing oral contraceptives, tamoxifen, raloxifen, thalidomide, or erythropoietin

Question 4

Physical examination

Answer 4

Wells score assessment

Question 5

Wells score

Answer 5

Wells’ criteria:

Active cancer (any treatment within past 6 months): 1 point

Calf swelling where affected calf circumference measures >3 cm more than the other calf (measured 10 cm below tibial tuberosity): 1 point

Prominent superficial veins (non-varicose): 1 point

Pitting oedema (confined to symptomatic leg): 1 point

Swelling of entire leg: 1 point

Localised pain along distribution of deep venous system: 1 point

Paralysis, paresis, or recent cast immobilisation of lower extremities: 1 point

Recent bed rest for >3 days or major surgery requiring regional or general anaesthetic within past 12 weeks: 1 point

Previous history of DVT or PE: 1 point

Alternative diagnosis at least as probable: subtract 2 points.

Question 6

Interpreting wells

Answer 6

> 2 points->diagnosis likely

Question 7

Occurence of DVT

Answer 7

1 in 1000 live adults

Question 8

Percentage of people who experience post-thrombotic syndrome after DVT

Answer 8

60%

Question 9

Investigations

Answer 9

Well's
D-dimer
Venous duplex USS
INT/aPTT
UEC
LFTs
FBC

CT abdomen pelvis if filling defect
Thrombophilia screen->no predisposing, recurrent, family history

Question 10

Tests in thrombophilia screen

Answer 10

Anti-cardiolipin
Lupus anticoagulant
Beta-2 glycoprotein
Protein C and S
Factor V leiden
Prothrombin
Antithrombin

Question 11

Management

Answer 11

Graduated compression stocking
Mobilisation
Enoxaparin
Warfarin

Question 12

Duration of warfarin

Answer 12

Clinical situation
Duration
VTE provoked by a transient major risk factor
3 months
unprovoked distal DVT
3 months
first unprovoked proximal DVT or PE
6 months 
first unprovoked VTE plus:
active cancer
multiple thrombophilias
antiphospholipid antibody syndrome
indefinite
recurrent unprovoked VTE
indefinite

Question 13

When would you consider IVC filter

Answer 13

When active bleeding

Anticoagulants fail

Question 14

Overview of approach to DVT prophylaxis

Answer 14

Reduce risks
Early mobilisation
Fluids
Pharmacotherapy
Mechanical
Analgesia
Physiotherapy

Question 15

Considerations for DVT prophylaxis

Answer 15

1. Surgery required
2. Other medical conditions which can +risk
3. Contraindications
4. Mechanical

Question 16

Surgical risk stratification general

Answer 16

1. Any surgical procedure
2. especially abdominal, pelvic, thoracic or orthopaedic surgery.
3. Major joint surgery and curative surgery for cancer carry very high VTE risk
4. leg injury requiring surgery or prolonged immobilisation
5. prolonged surgery and/or prolonged immobilisation.

Question 17

Medical conditions that can +risk

Answer 17

Chronic medical conditions
Paresis
\+Age (low risk)
OCP/HRT
Varicose veins (low risk)
Previous VTE
Thrombophilia
Malignancy
Trauma/surgery
Indwelling catheter
DM
Pregnancy/Peripartum
Extended travel
Myeloproliferative disease
CCF, COPD
IBD, Obesity (low risk)

Question 18

Contraindications to prophylaxis

Answer 18

Inherited/acquired bleeding disorder,
coagulopathy, DIC–>
Need INR, PTT

PLT disorders

Question 19

Differential diagnosis

Answer 19

Cellulitis
Calf muscle tear
Calf muscle hematoma
Baker's cyst
Pelvic/thigh mass/tumour compressing venous outflow from the leg
Thrombophlebitis
Compartment syndrome

Question 20

Differentiating features in cellulitis

Answer 20

1. Patients with cellulitis usually manifest redness, heat, and swelling in the dermis of the affected leg. The affected area is likely to be smaller than in DVT (which may involve the entire foot, calf, or thigh), but the signs more pronounced.
2. The demarcation of the skin margins more defined
3. Portal of infection entry may be identified. [71]
4. Fever and prior history of cellulitis is common.

May occur with a concurrent DVT

Question 21

Differentiating thrombophlebitis

Answer 21

Superficial inflammation of the veins with secondary thrombosis; manifests with a firm and tender varicose vein, low-grade fever, and oedema of the extremity