DVT & PE Flashcards
What is a PE?
Thromboemboli detach and travel through the right side of the heart to block vessels in the lungs
What cause haemodynamic collapse in PE?
right ventricle outflow doesn’t get round to left heart
What is a DVT?
Formation of thrombi within the lumen of the vessels that make up the deep venous system: venous valve pockets and other sites of presumed stasis
Describe an arterial clot?
Platelet rich clot
Why is venous clot fibrin rich?
in venous disease the bloodlfow is static and the coagulation cascade forms a fibrin rich clot
What percentage of cancer patients will have clot in their life?
20%
What are the three components of virchow’s triad?
Hypercoagulable state
Circulatory Stasis
Endothelial injury
What can contribute to hypercoagulable state?
Malignancy Pregnancy and permpartum period Oestrogen therapy IBD Sepsis Thrombophilia
What contributes to endothelial injury?
Venous disorders Venous valvular damage Trauma Surgery Indwelling catheters
What contributes to circulatory stasis?
Left ventricular dysfunction Immobility Paralysis Venous insufficiency or varicose veins Venous obstruction from tumour, obesity or pregnancy
Name some risk factors of clot?
Smoking Travel Prothrombin gene mutation Combined oral contraception Hormone replacement Protein C deficiency Protein S deficiency Factor V leiden mutation Pregnancy Active malignancy Day surgery Major surgery
What is a provoked VTE?
o transient reversible factors: surgery or hospitalisation
o continuing irreversible factors: cancer
What is an uprovoked VTE?
o unprovoked idiopathic: VTE
What type of VTE is likely to re-occur?
Unprovoked VTE; more likely to have reoccurrence than provoked over 10 yrs
What are the consequences of VTE?
- fatal PE
- risk of recurrent VTE
- post thrombotic syndrome (PTS)
- chronic thromboembolic pulmonary hypertension (CTEPH)
- reduced quality of life
What is PTS?
post thrombotic syndrome (PTS)
o characterised by pain: much more significant than what you can see
o clear brown discolouration- pooling blood
o venous ulceration
o oedema
o eczema
o varicose collateral veins
What is the treatment for PTS?
o compression stockings are pretty much the only limited treatment
What is CTEPH?
chronic thromboembolic pulmonary hypertension
o serious complication of PE
o relatively rare
o unexplained progressive breathlessness and hypoxia
o right heart failure
o mortality rates are 4-20%
What investigations can be done if VTE is suspected?
Pre-test probability scores
D-dimer
Ultrasound
What are the different types of ultrasound?
compressibility- put pressure on vein- if they can compress the femoral it suggests the pressure is not high above it and there is no more proximal clotting
Doppler- shows any turbulent flow
What is the significance of d-dimer in VTE?
- Low positive predictive value for VTE
- Valuable first line screening test for suspected VTE with low Wells score
- 25-50% patients require no further investigations
What are the other scoring systems for VTE probability?
Wells Score
Geneva Score
What imaging techniques can be used in VTE?
CXR
-Usually normal in PE. Can show pleural effusions and occasionally infarct
V/Q scan
- Ventilation/Perfusion imaging. Demonstrates mismatched perfusion defects. Still a useful test particularly in small peripheral PEs and pregnancy (perfusion only)
- have to have a normal CXR for it to be useful
- Limited by frequency of inconclusive results, hence
CTPA has become gold standard
How can we treat DVT and PE?
Pharmacological interventions
Mechanical interventions
recommended
Screening
