Deep Vein Thrombosis & Pulmonary Thromboembolism - Presentation, Investigation & Therapy

Question 1

where can thrombus occur?

Answer 1

arterial and venous

Question 2

what is a clot made up of?

Answer 2

fibrin

platelets

red blood cells

Question 3

what is the difference between arterial and venous in mechanism?

Answer 3

arterial-
usually rupture of atherosclerotic plaque

venous-
combination of virchows triad

Question 4

what is the difference between arterial and venous in location of origin?

Answer 4

arterial-
arteries, left heart chamber

venous-
venous valves and venous sinusoids of muscles

Question 5

what is the difference between arterial and venous in what it results in?

Answer 5

arterial-
ischaemia and infarction

venous-
back pressure

Question 6

what is the difference between arterial and venous in diseases?

Answer 6

arterial-
acute coronary syndrome
ischaemic stroke
limb claudication

venous-
deep vein thrombosis
pulmonary embolism

Question 7

what is the composition in arteries and venous?

Answer 7

arteries-
white thrombus- platelets and fibrin

venous-
red thrombus
red blood cells and fibrin

Question 8

what is the virchows triad of thrombosis?

Answer 8

stasis
hypercoagubility
endothelial damage

Question 9

what are examples of venous thromboembolism?

Answer 9

limb deep vein thrombosis

pulmonary embolism

Question 10

risk factors for venous thromboembolism?

Answer 10

major abdominal surgery
hip/knee replacement
late pregnancy
caesariam section
varicose veins
hospitilisation

Question 11

symptoms and signs for DVT?

Answer 11

unilateral limb swelling
persisting discomfort
calf tenderness

warmth
redness
prominant collateral veins
unilateral pitting oedema

Question 12

what is a potential long-term consequence of DVT?

Answer 12

post thrombotic syndrome

damage to venous valves

Question 13

what are symptoms of post thrombotic syndrome?

Answer 13

swelling
discomfert
pigmentation
ulceration in severe form

Question 14

how to diagnose DVT

Answer 14

Clinical assessment and pretest probability score (Wells score)

Blood test: D-dimer if low pre-test probability score

Imaging: Compression ultrasound if positive D-dimer or high pre-test probability score

Question 15

what is D dimer?

Answer 15

Breakdown product of cross-linked fibrin
Produced during fibrinolysis

High sensitivity for VTE

Low specificity for VTE
Trauma, malignancy, sepsis, bleeding, cancer, recent surgery

Question 16

symptoms and signs of PE

Answer 16

Pleuritic chest pain
Breathlessness-  dyspnoea
[Blood in sputum- haemoptysis]
Rapid heart rate- tachycardia
Pleural rub on auscultation 
usually due to pulmonary infarction

Question 17

symptoms and signs of massive PE

Answer 17

Severe dyspnoea of sudden onset
Collapse
Blue lips and tongue - cyanosis
Tachycardia
Low blood pressure
Raised jugular venous pressure
May cause sudden death

Question 18

diagnosis of pulmonary embolism?

Answer 18

Clinical assessment and pretest probability score (Wells score or Geneva score)
Blood test: D-dimer if low pre test probability score
Imaging: if D-dimer positive or high pre test probability score
Isotope ventilation/perfusion scan
CT pulmonary angiogram

Question 19

what are the aims of treatment of VTE?

Answer 19

prevent clot extension
prevent clot embolisation
prevernt recurrent clot

Question 20

treatment options?

Answer 20

Anticoagulation is main treatment

Parenteral options:
unfractionated heparin
low molecular weight heparin

Enteral options:
Warfarin
Direct Oral Anticoagulants (DOACs)

Thrombolysis reserved for massive PE
E.g. Alteplase

Question 21

prevention of VTE in hospital?

Answer 21

Early mobilisation
‘Anti-embolism stockings’
Other mechanical methods of thromboprophylaxis
Pharmacological thromboprophylaxis

Question 22

how do you develop a pulmonary infarction after PE?

Answer 22

Pulmonary infarction = rare due to dual vascular supply to lungs with anastomoses;
Pulmonary vascular system
Bronchial vascular system
Supply majority of O2 to lung parenchyma
Pre and post capillary anastomoses with pulmonary system

Blockage to a branch of the pulmonary artery = increase in pressure within pulmonary vasculature
Force within bronchial artery may be insufficient to overcome this
‘Leakage’ of blood into alveolar space occurs, and leads to infarction