DVT and PE Flashcards
(32 cards)
How can a DVT lead to a PE?
Embolises from deep veins, through right side of the heart and into the lungs where it becomes lodged in the pulmonary arteries
In what instance may a DVT lead to a stroke?
ASD
Clot can pass through to the left side of the heart into the systemic circulation to brain
List 4 risk factors for DVT/ PE
- Immobility
- Recent surgery
- Long haul flights
- Pregnancy
- COCP and HRT
- Malignancy
- Polycythaemia
- SLE
- Thrombophilia
List 2 examples of a Thrombophilia
- Antiphospholipid syndrome
- Antithrombin deficiency
- Protein C or S deficiency
- Factor V Leiden
VTE prophylaxis in hospital
Every patient admitted to hospital should be given LMWH eg. Dalteparin unless contraindicated
Anti-embolic compression stockings are also used unless contraindicated
List 2 contraindications for VTE prophylaxis
- Active bleeding
- Existing anticoagulation with warfarin or a NOAC
When are compression stockings contraindicated?
Significant peripheral arterial disease
What is the Wells score?
Predicts the risk of a patient with symptoms, actually having a DVT or PE
How does a DVT present?
- Unilateral warm, swollen calf or thigh
- Pain on palpation of deep veins
- Distention of superficial veins
- Pitting oedema
List 2 differentials for bilateral symptoms of DVT
More likely due to chronic venous insufficiency or heart failure
How to we examine/determine leg swelling?
Measure the circumference of the calf 10cm below the tibial tuberosity
3cm difference between calves is significant
What are the criteria for the DVT Wells score?
Investigations for a suspected DVT?
- D-dimer
- Doppler ultrasound of the leg ☆
- Digital subtraction or CT/MR venogram
What is the clinical relevance of D-dimer in diagnosis of DVT or PE?
↑Sensitivity, ↓ Specificity
Useful for excluding VTE in low clinical suspicion. ie. if negative VTE is extremely unlikely
List 4 causes of raised D-dimer
- PE/DVT
- Pneumonia
- Malignancy
- Heart failure
- Surgery
- Pregnancy
Management of a DVT?
- Initially: LMWH as soon as DVT suspected eg. enoxaparin and dalteparin
- Switch to long term anticoagulation: warfarin, NOAC or LMWH
List 3 examples of NOACs
apixaban, dabigatran and rivaroxaban
What is meant by an Unprovoked DVT
How is it investigated?
First instance of VTE without a clear cause
NICE recommend investigating them for possible cancer and testing for antiphospholipid syndrome
How does a PE present?
- SOB
- Cough +/- haemoptysis
- Pleuritic chest pain
- Hypoxia
- Tachycardia
- Raised RR
- Low grade fever
- Hypotension
What are the criteria for the PE Wells score?
Investigations for a suspected PE?
Perform Wells score and proceed based on:
- PE Likely: CT pulmonary angiogram
- PE Unlikely: D-dimer, if positive perform a CTPA
What ABG findings are typically seen in a PE
Explain
Respiratory alkalosis
High RR causes them to “blow off” extra CO2, blood becomes alkalotic
Management of a PE?
- Supportive: O2, Analgesia, monitoring
- Initially: Apixaban or rivaroxaban as soon as PE suspected
- Switch to long term anticoagulation: warfarin, NOAC or LMWH
How long should anticoagulation be continued for following a DVT or PE?
- 3 months if there is an obvious reversible cause
- > 3 months if cause is unclear, recurrent VTE or irreversible cause
- 6 months in active cancer
