Deep Vein Thrombosis & Pulmonary Thromboembolism - Presentation, Investigation & Therapy Flashcards
where can thrombus occur?
arterial and venous
what is a clot made up of?
fibrin
platelets
red blood cells
what is the difference between arterial and venous in mechanism?
arterial-
usually rupture of atherosclerotic plaque
venous-
combination of virchows triad
what is the difference between arterial and venous in location of origin?
arterial-
arteries, left heart chamber
venous-
venous valves and venous sinusoids of muscles
what is the difference between arterial and venous in what it results in?
arterial-
ischaemia and infarction
venous-
back pressure
what is the difference between arterial and venous in diseases?
arterial-
acute coronary syndrome
ischaemic stroke
limb claudication
venous-
deep vein thrombosis
pulmonary embolism
what is the composition in arteries and venous?
arteries-
white thrombus- platelets and fibrin
venous-
red thrombus
red blood cells and fibrin
what is the virchows triad of thrombosis?
stasis
hypercoagubility
endothelial damage
what are examples of venous thromboembolism?
limb deep vein thrombosis
pulmonary embolism
risk factors for venous thromboembolism?
major abdominal surgery hip/knee replacement late pregnancy caesariam section varicose veins hospitilisation
symptoms and signs for DVT?
unilateral limb swelling
persisting discomfort
calf tenderness
warmth
redness
prominant collateral veins
unilateral pitting oedema
what is a potential long-term consequence of DVT?
post thrombotic syndrome
damage to venous valves
what are symptoms of post thrombotic syndrome?
swelling
discomfert
pigmentation
ulceration in severe form
how to diagnose DVT
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
what is D dimer?
Breakdown product of cross-linked fibrin
Produced during fibrinolysis
High sensitivity for VTE
Low specificity for VTE
Trauma, malignancy, sepsis, bleeding, cancer, recent surgery
symptoms and signs of PE
Pleuritic chest pain Breathlessness- dyspnoea [Blood in sputum- haemoptysis] Rapid heart rate- tachycardia Pleural rub on auscultation usually due to pulmonary infarction
symptoms and signs of massive PE
Severe dyspnoea of sudden onset Collapse Blue lips and tongue - cyanosis Tachycardia Low blood pressure Raised jugular venous pressure May cause sudden death
diagnosis of pulmonary embolism?
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
what are the aims of treatment of VTE?
prevent clot extension
prevent clot embolisation
prevernt recurrent clot
treatment options?
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
prevention of VTE in hospital?
Early mobilisation
‘Anti-embolism stockings’
Other mechanical methods of thromboprophylaxis
Pharmacological thromboprophylaxis
how do you develop a pulmonary infarction after PE?
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
