Venous Thromboembolic Disease (DVT/PE) Flashcards
What is a thrombus?
Intra-vascular coagulation of blood
What is prothrombin time?
Measure of clotting tendency of the blood
What are risk factors for DVT?
Age Pregnancy Trauma Surgery Obesity Cancer Immobility Thrombophilia (smoking/contraceptive pill/renal-nephrotic syndrome/cardiomyopathy)
What is Factor V Leiden?
(Genetic) Thrombophilia
What are the three components of Virchow’s triad?
Endothelial injury
Circualtory stasis
Hypercoaguability
What are causes of endothelial injury?
Venous valve damage Trauma Surgery Indwelling catheter Central line venous damage Smoking Toxins Infectious agents Autoimmune Vasculitis
What are causes of circulatory stasis?
Venous insufficiency Varicose veins Venous obstruction Immobility Paresis
What are causes of hypercoagulability?
Malignancy Pregnancy HRT IBD Sepsis Thrombophilia
Thrombi typically occur in the ______
Venous system
venous valve pockets and other sites of presumed stasis
What are symptoms / signs of DVT?
Calf leg - pain, swelling, hot, inflamed
Localised tenderness of deep veins
What are investigations to diagnose DVT?
D-dimer
Duplex scanning
Venous plethysomography
What is D-dimer?
Breakdown product of cross-linked fibrin
What are complications of DVT?
Pulmonary embolism (PE) Post-thrombotic syndrome (PTS)
What is post-thrombotic syndrome (PTS)?
Pain, oedema, hyper pigmentation, exczema, varicose, collateral veins, venous ulceration
Damage to deep vein valves and valvular reflux
Causes venous hypertension
How do you treat DVT?
Anticoagulation with LMWH and Warfarin
Compression stocking
IVC filters
Prevention screening
What is the purpose of compression stockings?
Increase venous blood flow
+/- help with pain
What is an IVC filter and what is its purpose?
Blockage ‘cage’ in IVC to stop clots entering
metal device - can cause problems itself
What causes a PE?
Superadded thrombus ad plaque material may break off and embolism
Usually originates from a DVT in the legs/pelvis - detaches and travels to the right side of the heart to block vessels in the lungs
A massive PE causes?
Shock / Syncope
A major PE causes?
Right ventricular dysfunction
What are the three types of PE?
Massive
Major
Minor
What are the symptoms of a PE?
Acute dyspnoea Collapse Pleuritic chest pain Haemoptysis Sudden death
What are the signs of a PE?
Tachypnoea Hypertension Cardiorespiratory arrest Tachycardia S4 Accentuated pulmonic component of S2 Pleural rub
What would be seen on CXR for a PE?
Westermark sign (oligemia)
Wedge-shaped infarced
Pleural effusion
Consolidation on CXR
Which investigations can be done to diagnose a PE?
ABGs CXR - wedge-shaped infarct, often normal V/Q scan CTPA ECHO (Angiogram rarely) Bloods: FBC, U&Es, baseline clotting, D-dimer
What is the Westermark sign?
Collapse of a vessel
How do you treat a minor PE?
Anticoagulants
How do you treat a massive PE?
Thrombolysis
Surgery
How do you treat a major PE?
Anticoagulants
Thrombolysis
Which drug can be given to prevent venous thrombosis post-op/hip replacement?
Daigatran etexilate or Rivaroxaban
Dabigatran etexilate is?
An orally active thrombin inhibitor
What is the major disadvantage of dabigatran and rivaroxaban
No predictable agent to reduce haemorrhage in overdse
Rivaroxaban is a?
Factor Xa inhibitor
