Deep Vein Thrombosis and Pulmonary Embolus

Question 1

What is VTE?

Answer 1

Venous thrombo embolic disease

25,000 deaths/ye in UK

Question 2

What is a thrombosis?

Answer 2

Intravascular solidification of blood constituents

Question 3

What is an embolism?

Answer 3

Vascular obstruction at a site distant from the embolus origin

Question 4

How common is DVT?

Answer 4

1 in 20 affected during lifetime

1 / 1000 people / yr

Question 5

What is Virchaus Triad?

Answer 5

Alterations in blood flow
Alterations in blood constituents
Vascular endothelial injury

Question 6

What are the 9 main acquired risk factors for VTE?

Answer 6

malignancy
surgery
trauma
immobility
obesity
pregnancy
HRT
previous thrombo-embolism
oral contraceptive pill

Question 7

What are the 4 main inherited risk factors for VTE?

Answer 7

Factor V mutation
Prothrombin gene mutation
Protein ‘S’ or ‘C’ deficiency
Antithrombin III deficiency

Question 8

How does DVT present?

Answer 8

Pain, tenderness, swellign, erythema, heat, venous engorgement

Question 9

What are the differential diagnoses of DVT?

Answer 9

cellulitis, lymphoedema, muscle strain/tear, drug induced oedema, chronic venous insufficiency

Question 10

How to investigate DVT?

Answer 10

D-dimer blood test
USS / Doppler
venogram

Question 11

What is a D-dimer blood test?

Answer 11

method of investigating DVT. It looks at the products of thrombus fibrinolysis. Plasmin enzyme breaks down the fibrin mesh but it is unable to break the bonds between 1E and 2D units. The remaining protein fragment is a D-dimer

Question 12

What are the problems with the D dimer test?

Answer 12

95% Sensitivity

50% Specificity

Question 13

What are secondary results of DVT?

Answer 13

Venous insufficiency - hyper pigmentation, limb pain, swelling, dermatitis, ulcers, gangrene
Recurrent DVT
Pulmonary embolism

Question 14

What is a pulmonary embolism (PE)?

Answer 14

Obstruction of a pulmonary artery or one of its branches (usually from DVT but can be from tumour or fat)

Question 15

How does a PE present?

Answer 15

collapse
pleuritic chest pain
dyspnoea
tachypnoea
tachycardia

Question 16

What is the treatment for a PE?

Answer 16

Uncomplicated PE - immediate anticoagulation with heparin

Major PE - systemic thrombolysis, catheter embolectomy with local thrombolysis, surgical embolectomy

Question 17

Indications for thrombolysis?

Answer 17

Massive PE
Hypotension
Systemic hypo-perfusion

Question 18

How can PE be prevented?

Answer 18

Calf pumping
LMWH
Early mobilisation

Question 19

When should an IVC filter be used for PE treatment?

Answer 19

If PE with contraindication to anticoagulation or if recurrent PE despite adequate anticoagulation

Question 20

What are NOACS?

Answer 20

Novel Oral Anticoagulants.
Developed because warfarin is awkward to use and cause a high degree of morbidity, mortality and cost.
They require minimal monitoring as can cause adverse effects through bleeding and interact with drugs which affect haemostasis

Question 21

Name and describe 2 NOACS?

Answer 21

Dabigatran - direct thrombin inhibitor

Rivaroxaban and apixaban - direct factor Xa inhibitors

Question 22

What are NOACS currently licensed for?

Answer 22

Prevention of VTE around surgery and being used as anticoagulation in atrial fibrillation