4: Venous thrombosis Flashcards
.Thrombosis can be either ___ or ___.
arterial or venous
What is a common type of venous thrombosis?
What lethal consequence can it have?
DVT
Pulmonary embolism
Where do DVTs occur?
Why?
Lower limbs
Virchow’s triad
What is the pathophysiology of arterial thrombosis?
Atherosclerotic disease
with a background of hypertension, hyperlipidaemia, diabetes….
What are some presentations of arterial thrombosis?
Angina
Intermittent claudication
Stroke
Which blood components are involved in arterial thrombosis?
Platelets
so prevent with anti-platelets
Apart from starting anti-platelet drugs, what can a patient do to reduce their risk of arterial thrombosis?
Modify risk factors through lifestyle
Are platelets involved in arterial thrombosis?
Yes
Are platelets involved in venous thrombosis?
No
Fibrin - treat with anti coagulants
Which anti-coagulant drugs are used to treat venous thrombosis?
Warfarin
Heparin
NOACs
What is Virchow’s triad of venous thrombosis?
Endothelial damage
Hypercoagulability
Stasis
What is meant by hypercoagulability?
Increased tendency to clot
Blood disorders e.g thrombophilia, polycythaemia
Acute inflammation (clotting factors are acute phase proteins)
Pregnancy (physiological increase in clotting factors)
Which traditional anti-coagulants are used
a) acutely
b) chronically?
a) Heparin
b) Warfarin
What are the classic symptoms of a DVT?
Warm, swollen, oedematous, painful lower limb
Usually asymmetrical
What are the symptoms of a PE?
Pleuritic chest pain
SOB
Haemoptysis
What are the characteristic ECG findings in PE?
S1 Q3 T3
What are some risk factors for VTE?
Increasing age
CVD risk factors
Pregnancy
Hormonal trherapy
Trauma, malignancy, infection, thrombophilia…
i.e VITAMINS ABCDEK
In which states do clotting factor levels increase?
Obesity
Pregnancy
Hormonal contraception
Infection
Malignancy…
i.e all of them again
Which inherited blood disorder greatly increases your chances of developing VTE?
Thrombophilia
Which protein switches off thrombin and acts as a natural anticoagulant?
Antithrombin
Apart from antithrombin, which other naturally occuring proteins act as anticoagulants?
Protein C and Protein S
Thrombin (with thrombomodulin)
Which protein, affected by a common gene mutation, inhibits the activity of Protein C and S?
Factor V Leiden
What is the risk of VTE in a patient with a Factor V Leiden mutation compared to the general population?
5x population average
Which anticoagulant proteins are affected by mutations causing thrombophilia?
Antithrombin
Protein C and S
Factor V
In which groups of patients would you consider screening for inherited thrombophilias?
People with VTE aged < 40
People with recurrent VTEs
People with VTEs in weird places
People with family histories of thrombophilia
The period after ___ is highest risk for VTE.
period after pregnancy
i.e the peurperium
Which form of contraception increases a woman’s risk of VTE by 7 times?
OCP
Risk factors for VTE tend to ___.
accumulate
e.g age, immobility, OCP, Factor V Leiden, Fx, Hx over time…
multiplying risk
What is the risk of using anticoagulation to prevent or treat VTE?
Abnormal bleeding
other end of the spectrum
Which autoimmune condition causes acquired thrombophilia?
Anti-phospholipid syndrome
What condition is APS associated with?
Systemic lupus erythematosus (SLE)
Another autoimmune disease
What occurs in aPS?
Recurrent arterial and venous thrombosis
Recurrent miscarriage
What is given to pregnant women with known aPS?
Prophylactic heparin (anti-coag) and aspirin (anti-platelet)
What are the three important anti-phospholipid antibodies?
Anti-B2 glycoprotein
Anti cardiolipin
Anti lupus anticoagulant
Which clotting time is prolonged in antiphospholipid syndrome?
APTT
Which autoimmune disease is associated with aPS?
SLE
How is aPS treated?
Anti-platelet - aspirin
Anti-coagulant - warfarin
life long
modify CVD risk factors
