Thrombosis Flashcards
Describe the formation of an arterial thrombosis
atheroma forms
platelets stick to damaged endothelium and aggregate in response to ADP and TXA2 release
plaque rupture exposes TF
triggers coag cascade and thrombus forms
What is an arterial plaque mostly made of?
Cholesterol and platelets
What is the treatment of an arterial thrombus?
anti-platelets
What lifestyle advice is relevant to arterial thrombus?
Stop smoking
Exercise
Lose weight is appropriate
Cut down on alcohol
What does a venous clot mainly consist of?
Fibrin and red cells
What are the components of Virchow’s triad?
Stasis
Hypercoag
Vessel wall abnormality
Give examples of what would cause stasis
Paralysis
Prolonged hospital stay
Obesity
Surgery
Give examples of what would cause hypercoagulability
Pregnancy Age OCP use Surgery Malignancy infection
Give examples of what could result in a vessel wall abnormality
Valve problems
Prev DVT
Age
How does a DVT present?
Hot swollen, tender, pitting oedema, pain
How is DVT treated in pregnancy?
LMWH
What is a PE?
Embolus from DVT travels to pulmonary vasculature
How does PE present?
Pleuritic chest pain
CV collapse
Hypoxia
Right heart strain
What do investigations show on PE?
d-Dimer raised
ECG shows T wave inversion in lead III
What is thrombophilia?
Abnormal tendency to clot
Is secondary or primary haemostasis affected in thrombophilia?
Both
When should thrombophilia be considered?
VT <40s
Recurrent VT or miscarriage
VT in abnormal place
AT but no arterial disease
Which naturally occurring anti-coags are present in the body?
Anti-thrombin
Protein C and S
How are protein C and S activated?
Thrombin binds to thrombomodulin to activate the proteins
What does anti-thrombin do?
Switches off thrombin
What do protein C and S do?
Inactivates factors V and VIII
What is factor V Leiden?
Single nucleotide variation in factor V which makes is less efficiently switched off by protein C and S
Where is the prothrombin variant mutation?
In the untranslated region of the prothrombin gene
How is anti-thrombin def inherited?
AD
How may anti-thrombin def be acquired?
After trauma, surgery and OCP
Which anti-coag drug are patients with anti-thrombin def resistant to?
Heparin
How are protein C and S defs inherited?
AD
What lethal complication can protein C and S def cause?
Neonatal purpura fulminans
How is protein C def treated?
Plasma derived protein C given
What is the management of a confirmed thrombophilia with no clots?
Avoidance of risk
Lifestyle modification
When would short term prophylaxis be given in thrombophilia?
Periods of known risk eg: surgery, pregnancy, long haul flight
When would long term prophylaxis be considered in thrombophilia?
Recurrent thromboses
Which antibodies are found in anti-phospholipid syndrome
anti-cardiolipin
Lupus anticoag
What are the clinical features of anti-phospholipid syndrome?
Mild thrombocytopenia
Recurrent foetal loss
Recurrent thromboses
What do the antibodies in anti-phospholipid syndrome do?
Act on beta-2 glycoprotein 1
Leads to activation of primary and secondary haemostasis
