Formation of a mass (thrombus) from the constituents of blood within the vasculature during life
How does a thrombus differ from a clot?
Thrombus must form during life in the body; clots can form when blood is extracted post-mortem
What are the 3 components of Virchow’s triad?
Changes in blood flow
Changes in blood coagulability
Give some examples of hypercoaguable aquired states
Myocardial infarction Immobility Cancer Prosthesis AF Cardiomyopathy Oral contraceptive use
Arterial thrombi are red. True/False?
Where do arterial thrombi often lodge?
Coronary, cerebral, femoral circulations
Detached intravascular solid/liquid/gas mass carried distal to point of origin
Venous emboli commonly infarct peripheral circulation. True/False?
False Very rare (carried to pul circulation, more likely lodge there)
Give examples of factors causing endothelial injury
Smoking Hyperlipidaemia Hypertension Toxins Infection
Give examples of what happens due to endothelial dysfunction
Macrophage + platelet adhesion and activation
Once macrophages are activated on the endothelial surface, what do they generate?
Oxidative free radicals
What do oxygen free radicals do to LDL?
Ingest and trap it within macrophages, forming foam cells/fatty streaks
In a pre-test probability (PTP) score for DVT, the scoring does not apply in what situations?
If you have had a previous DVT
If you are pregnant
A PTP score for DVT of 3 or more is high risk. True/False?
D-dimer can both rule out and diagnose DVT. True/False?
What is D-dimer?
A breakdown product of fibrin
If D-dimer levels are low, a DVT is unlikely. True/False?
If D-dimer levels are high, a DVT is very likely. True/False?
D-dimer levels are raised by many things (infection, MI, surgery)
If your PTP score is low and D-dimers are low, a DVT can be excluded. True/False?
If your PTP score is low and D-dimers elevated, what is the next investigation for diagnosing a DVT?
If your PTP score is high and D-dimers low and US negative, DVT can be excluded. True/False?
If your PTP score is high and D-dimers high but US negative, DVT can be excluded. True/False?
Repeat US before completely excluding DVT
What is the mainstay of DVT treatment?
Anticoagulation (LMWH heparin, warfarin)
TED compression stockings
What is phlegmasia dolens?
DVT causes obstruction of arterial flow due to back pressure created
How is phlegmasia dolens usually treated?
IVC filter through femoral artery which prevents thrombus entering lungs
What is the first line imaging modality of choice for PE?
What is the advantage of a caval filter for acute PE?
Prevents recurrence of PE in short term
What is the drawback of a caval filter?
Increases risk of DVT - patients will require anticoagulation if long-term filter
When is warfarin contraindicated?
Increased haemorrhage risk (uncontrolled drug abuse, dementia etc.)