Thrombotic Disorders Flashcards
What are the main risk factors for VTE?
- Immobility
- Recent surgery
- Long haul flights
- Pregnancy
- Hormone therapy with oestrogen
- Thrombophilia
What hormone therapy increases the risk of VTE?
Combined oral contraceptive pill
Hormone replacement therapy
What are thrombophilia’s?
Conditions that predispose patients to develop blood clots and therefore VTE
What are the most common type of thrombophilia’s?
- Factor V Leiden
- Prothrombin gene variant
- Antiphospholipid syndrome (Important)
What are the more rare causes of thrombophilia?
- Antithrombin deficiency
* Protein C or S deficiency
Who should be assessed for their risk of VTE?
Every patient admitted to hospital
What should people at risk of VTE be given?
Low molecular weight heparin- Enoxaparin
What are the possible complications of LMWH (Enoxaparin)?
Active bleeding
Existing anticoagulation with warfarin or a NOAC
What is the non-medical prophylaxis of thrombotic disorder?
Compression stockings
What is the main contraindication of compression stockings?
Peripheral arterial disease
How does DVT usually present?
Unilaterally
When would bilateral DVT present?
Chronic venous insufficiency
Heart failure.
Are bilateral DVT’s common?
No- rare
How do DVT’s present?
- Calf or leg swelling
- Dilated superficial veins
- Tenderness to the calf (particularly over the site of the deep veins)
- Oedema
- Colour changes to the leg
What are the 2 main tests for DVT?
Well’s score
D-dimer
What is the Well’s score used to predict?
The risk of a patient presenting with symptoms actually having a DVT or pulmonary embolism
What does the Well’s score take into consideration?
Recent surgery
Clinical findings- unilateral calf swelling 3cm greater than the other leg.
When is D-dimer test useful for?
Excluding VTE where there is a low suspicion.
What type of test is D-dimer?
Sensitive (95%) but not specific blood test for VTE.
What other conditions can D-dimer be raised with?
- Pneumonia
- Malignancy
- Heart failure
- Surgery
- Pregnancy
What is required for the diagnosis of DVT?
Ultrasound doppler of the leg
If doppler ultrasound of the leg is negative, when is it recommended to repeat it?
After 6-8 days if:
There is a positive D-dimer
The Wells score suggest a DVT is likely.
What is the gold standard diagnosis of a pulmonary embolism?
CT pulmonary angiogram
What other investigation can be done for a pulmonary embolism?
Ventilation–perfusion (VQ) scan.
What is the first line management of DVT?
DOAC- Apixaban or rivaroxaban
When would you give a DOAC?
Following the diagnosis of a DVT or until the diagnosis is confirmed
When should you continue to use a DOAC?
When the diagnosis has been confirmed
What is the medical management of a DVT if a DOAC isn’t suitable?
- LMWH followed by dabigatran or edoxaban
* LMWH followed by a vitamin K antagonist (VKA, i.e. warfarin)
When should you give someone LMWH as an alternative to a DOAC?
When they have renal impairment
How long should treatment for DVT be continued?
At least 3 months
What does the length of treatment depend on?
Whether the DVT was provoked or unprovoked
What is a provoked DVT?
Due to an obvious precipitating event e.g. immobilisation following major surgery
What is an unprovoked DVT?
Occurs in the absence of an obvious precipitating event
How long should should a provoked DVT be treated?
Stop treatment after 3 months
How long should an unprovoked DVT be treated?
6 months
