Thrombosis and risk factors of thrombosis Flashcards
what is virchows triad
blood flow, composition of blood and vascular endothelial.
what is the primary cause of a arterial thrombosis
atherosclerosis.
what is the pathogenesis of a arterial thrombosis
rupture of a atheromatous plaque
endothelial injury
platelet aggregation and platelet thrombi.
risk factors for arterial thrombi formation
smoking, hypertension, hypercholesterolaemia, diabetes, family history, obesity, physical inactivity, male and sex.
what is the main component of a venous thrombus
fibrin
what is the pathogenesis of venous thrombosis
venous stasis
hypercoagubale states.
symptoms of DVT
swollen, red, hot to touch, painful, unilateral leg
what secondary condition is DVT above the leg likely to present with
Pulmonary embolism
symptoms of PE
chest pain, breathlessness and haemotypysis.
how can hospital acquired VTE be prevented
risk assessment
prophyalaxis- “Low dose” low molecular weight heparin, fondaparinux
Newer anticoagulants- direct inhibitors of Factor Xa: rivaroxaban, direct thrombin inhibitors : dabigatran
how is hospital acquired VTE treated
care pathway- anticoagulant drugs.
If patient is at increased risk of bleeding provide stocking to improve circulation to the legs
what are the risk factors of VTE
- Active cancer or cancer treatment
- Age over 60 years
- Critical care admission
- Dehydration
- Known thrombophilias
- One or more significant medical comorbidities
- Surgery
- Major Trauma
- Personal history of VTE
- Use of hormone replacement therapy
- Use of oestrogen-containing contraceptive therapy
- Varicose veins with phlebitis
- Obesity (BMI over 30 kg/m2 )
- Pregnancy and postnatal period
- Immobility
- First degree relative with VTE
what molecules does unfractionated heparin work on.
anti thrombin (2 sites) and anti Xa
what molecule does LMW heparin bind
anti Xa, and anti thrombin
Factor Xa inhibitor
what molecule does Fondaparinux find to
anti Xa
what molecule do direct thrombin inhibitors act on
thrombin
What does a d-dimer test show
D-dimer breakdown product form fibrin clot.
Indicates that a clot was previously present although it has now been broken down
how can a ultrasound help diagnose a thrombus
Look for loss of flow signal, intravascular defects or non collapsing vessels in the venous system.
Vessels with clot will not compress if you apply pressure with the ultrasound probe.
what is a spiral/multi sliced CT used for
detect PE
what is a VQ scan
radio isotope scan.
Compare radioisotope pattern of a inhaled isotope (ventilation scan), injected isotope (perfusion scan)- this is diagnostic of DVT.
treatment plan for a uncomplicated patient with dot
Suspected DVT- single dose LMWH
confirm diagnosis-LMWH for 5 days.
Start warfarin
Start patient-held anti-coagulant book + inpatient warfarin chart
which anticoagulants are used as both treatment and prevention of DVT
- Rivaroxaban, Apixaban- direct factor Xa inhibitor
- Dabigatran- diresct thrombin inhibitor.-oral.
- Fondaparinux, LMWH- paraenteral
how long is DVT/VTE treated for upon first episode and what medication is typically used
3-6 months.
warfarin
what are recurrent episodes Recurrent episodes of VTE.
Treat with long term anticoagulation.
Recurrent episodes of VTE.