Deep Vein Thrombosis and Pulmonary Embolism Flashcards
What are the 3 parts of Vichow’s triad?
Changes to vessel wall - damage due to atherosclerosis
Changes to blood flow - stasis due to being bed bound or travel (on planes)
Changes to vessel constituents - hypercoagubility due to trauma or pregnancy
What is a thromboembolism?
Movement of a clot along a vessel causing an embolism
What are the differences between venous and arterial thrombi?
Venous:
Red thrombus made of fibrin and RBCs
Results in back pressure (of veins)
Mainly due to stasis and hypercoagubility
Arterial:
White thrombus made of fibrin and platelets
Results in ischaemia and infarction
Mainly due to atherosclerosis - vessel damage
Examples of venous thromboembolisms?
Limb DVT
Pulmonary embolism
Visceral venous thrombosis
Intracranial thrombosis
What are the symptoms and signs of a DVT?
Unilateral limb swelling Persisting discomfort Calf tenderness Warmth Redness
It can be clinically silent though
What is the initial diagnostic test for DVT?
Clinical assessment and a pretest probability score known as the wells score
If high - imaging
If low next test
What is the second test if the pre-test probability score is low?
Blood test looking for D-diamers
What imaging is used and when would it be used?
Compression USS if a positive D-dimer test or a high test score
Long term consequences of a DVT?
Post thrombotic syndrome happens to 20-60% of patients within 2 years of a DVT
Causes:
swelling,
discomfort,
pigmentation
ulceration in most severe form
Signs of a pulmonary embolism?
Pleuritic chest pain Dyspnoea Haemoptysis Tachycardia Plural rub heard on auscultation
Signs of a massive PE?
Severe dyspnoea of sudden onset Collapse Central cyanosis Tachycardia Raised JVP
Can a massive PE cause sudden death?
Yes
Diagnosis of a PE?
Same steps as a DVT but imaging used is:
Isotope V/Q scan
CT pulmonary angiogram
Long term consequences of a PE?
Most fully recover
Can cause pulmonary hypertension
Treatment aims for a venous thromboembolism (VTE) event?
A VTE comprises a DVT and a PE
Aims are to prevent clot extension and embolism and prevent recurrence of a colt
What types of medical therapy is used?
Antocoagulants
Thrombolysis
What are the parenteral (non oral) options of anticoags?
Unfractionated heparin
LWMH
What is the enteral (oral) options?
Warfarin
Direct oral anticoags
When is thrombolysis used?
Massive PE
If patient pregnant what drugs should we not use and what one is best to use?
Thrombolysis rarely used during pregnancy caused VTEs as its reserved for massive PEs
Can’t use warfarin as it is teratogenic - harms development of baby
Use LWMH
How would we prevent a VTE in a hospital setting?
Early mobilisation to keep patient moving and stopping stasis of flow
Other mechanical or pharmcological methods of prophylaxis
