Flashcards in Thrombotic disorders Deck (18)
Deep vein thrombosis-
Thrombosis (blood clot), in a deep vein in the leg.
Endothelial injury/ dysfunctions
Thrombosis risk factors
Post-operative injury- especially orthopaedic.
OCP- oral contraceptive pill
IV drug abuse- veins.
Hypercoagulability causes for DVT
Haemodynamic causes for DVT
Endothelial injury/dysfunction causes for DVT
Bacteria/ foreign materials
Clinical presentation of DVT
A lot of the times it is asymptomatic.
Unilateral calf swelling
Heat, pain, redness and hardness in leg.
Diagnosis of DVT
Shows blood velocity and flow through the colour duplex.
Non-compressible veins indicate a thrombosis.
Wells risk score:
Low score indicates increase predictive value for having a DVT.
Presence indicates the activation of the clotting cascade.
Low wells score and negative D-dimers test indicate high negative predictive value >99%.
Initial treatment of DVT
Low molecular weight heparin is given- Tinzaparin or enoxaparin.
Dosing is calculated according the weight- with no monitoring required.
IF patient has renal failure/ impairment- IV unfractionated heparin is used to maintain APTT 1.5-2.0
Later treatment of DVT
1. Oral warfarin is loaded into patients for 3-5 days.
2. Stop LMW heparin when the INR (international normalised ratio) is >2.0, for 2 days.
3. If it is the first DVT- warfarin is administered for 6 months post. If it is the second DVT then warfarin given for lifetime.
Thrombosis in the pulmonary artery- resulting from the mobilisation of a DVT.
Massive emboli- syncope, death
Symptoms of PE
- Pleuritic pain
Could also be:
Investigations into PE
CTPA- CT pulmonary angiogram- shows clot in BV.
V/Q scan- radio-isotope that shows underperfusion due to V/Q mismatch. BUT it is affected by underlying lung problems.
Right heart strain
SI, QIII, TIII
CXR: usually normal but there may be linear atelectasis or small effusions
Effects of PE
Development of pulmonary HT- 4%
5% mortality with treatment
Massive PE treatment
Thrombolysis and IV heparin
Standard treatment of PE
LMW heparin injections- Tinzaparin
Better for underlying cancer
Warfarin administered to trager INR 2.5 for 6 months
Screen is done in young patients with VTE
Inherited or acquired.
Factor V Leiden
Prothrombin gene variant
Protein C/ S deficiency