VENOUS THROMBOSIS Flashcards
Where may arterial thrombitic events occur?
- coronary
- cerebral
- peripheral
Cause of blood clots in arterial system?
- chronic high pressure damages the vascular endothelium leading to eventual atherosclerosis> presents as angina if in heart/ claudication in legs
- rupture results in PLATELET rich thrombus !
How to treat arterial thrombosis?
- ASPIRIN and ANTI-PLATELET drugs
- modify risk factors (high BP/ smoking)
How does venous thrombosis occur?
- its a low pressure system
- —tends to be stasis problem
- which ACTIVATES the coagulation cascade> fibrin clot formation
What is given to treat venous thrombosis?
- Heparin and Warfarin
- Anti-coagulants
What is involved in Virchow’s triad?
- stasis
- vessel wall (deterioration of the valves) —occurs with AGE and blood clot formation
- hypercoagulability (Tissue factor/ vWF)
- —–ANTI-THROMBIN AND PROTEINS S may drop!
How does DVT present as?
Blood fails to return to heart!
- —limb feels HOT, swollen, tender
- pitting edema
What is a DDX for dvt?
- -CELLULITIS (also unilateral)
- lymphedema (cancer blocking the lymphatic flow)
- -CHF is b.l
How does a P.E come about
blood clot from DVT travels through the IVC to the heart, through the pulmonary artery into the LUNGS
—occludes small vessel in lungs> tissue hypoxia
How does P.E present as?
-hypoxia
- pleuritic pain (STABBING pain on inhalation!) —S1Q3T (ECG) ????
inflammed lung lining rubs on the pleura?
Why is hypercoagulability seen in pregnancy?
- factor VIII RAISES by 5x in pregnancy
What are some hypercoagulable states ?
- age
- Prgenancy
- Puerperium
- Estrogen therapy
- Trauma/ surgery
- Malignancy
- Infection
- Thrombophilia (heritable/ anti-phosholipid syndrome)
What component of the normal haemostatic system is affected in venous thromboembolism?
– anticoagulant defences
What is seen with thrombophilia?
- familial/ acquired d.o of the haemostatsis mechanism
- -predisposing one to thrombosis
What is seen with thrombophilia?
- FACTOR 5 normal fxn
- –but unable to switch off efficiently
- –5x incr. risk of getting blood clt.
What IS responsible for switching off Factor 5 and 7?
Protein C and Protein S
When to consider screening for Hereditary thrombophilia?
Venous thrombosis <45 years old
Recurrent/ Unusual VENOUS thrombosis
Family history of venous thrombosis
Family history of thrombophilia
How to manage hereditary thrombotic events?
avoid OCP (
- short- term prophylaxis (to prevent thrombotic events)
- short term anticoagulation (to treat thrombotic event)
- long-term anti-coagulation (if RECCURENT)
Are multiple risk synergistic ?
YES
- —if you have family hx and your on OCP
- —HUGE risk !
What occurs with acquired thrombophilia?
- THROMBOSIS IN BOTH arteries and veins
- —YOUNG pt with stroke
- -said to be d.t anti-phospholipid syndrome
What are the fts of anti-phospholipid syndrome?
- recurrent FETAL loss
- mild thrombocytopenia
- recurrent thromboses (TIAs and venous)
Why may APTT be prolonged in Antiphospholipid syndrome?
- –Lupus anticoagulants (Abs) interfere with the test
- –prolongation WITHOUT factor deficiency occurring
What is A.W antiphospholipid Abs?
- EBV may trigger the autoimmune d.o
- lymphoproliferative d.o
- viral infections
- drugs
- primary
Rx of Antiphospholipid syndrome?
- Warfarin
prevent both Iary and IIary haemostasis
What results in arterial and venous thrombosis respectively?
Arterial= atjeroscleorsis; subsequent rupture
Venous= Virchow’s triad
Which condition holds a HIGHER risk
for thrombosis than hereditary thrombophilias?
Antiphospholipid Ab syndrome
What occurs with pulmonary embolism pathologically?
pulmonary infarction
- pleuritic chest pain
- cardiovascular collapse/ death
- HYPOXIA
- right heart strain
What are the risk factors for STASIS to occur?
- age
- pregnancy
- marked obesity
- DVT/ PE
- malignancy
- paralysis
- surgery/ trauma
What vessel wall risk factors predisposes one to venous thrombosis?
Age
Previous DVT/PE
What is a specific hypercoagulable state? Why does it occur?
thrombophilia
- decr. anti-coagulant activity / decr. fibrinolytic acivity/ incr, coagulation activity (fibrin clot and platelet plug formation)
Name some naturally occurring anti-coagulants.
- Serine Protease Inhibitor (anti-thrombins)
- Protein C and Protein S
- Tissue Factor pathway inhibtitor
What follows IIary haemostasis?
What carries out fibrinolysis?
To prevent Inappropriate, dangerous clotting elsewhere- FIBRINOLYTIC cascade follows
—carried out by PLASMIN (breaks down fibrin)
What is hereditary thrombophilias?
- gr. of genetic defects
- individuals have INCR. tendency to develop PREMATURE, unusual and recurrent thromboses
What is said to be the pathogenesis of anti-phospholipid abs?
- Abs cause a conformational in Bets1 Glycoprotein 1
> activation of Iary and IIary haemostasis and vessel wall abnormalities
Most common genetic defect mounting to DVT?
Factor V Leiden
