Pulmonary Embolism Flashcards
What is a pulmonary embolism?
When the pulmonary artery gets blocked by a blood clot
Where does the thrombus usually arise from in a PE?
Deep vein in leg e.g. popliteal vein, femoral vein
Symptoms of PE?
Small emboli may be asymptomatic
Acute pleuritic chest pain
SOB
Syncope
Signs of PE?
Sinus tachycardia - most common
Tachypnoea
Pleural rub
Raised JVP
Risk factors for PE?
Recent surgery – esp abdo/pelvic, hip/knee Thrombophilia Leg fracture Prolonged bed rest Malignancy Pregnancy, COCP, HRT
Sign of PE on CXR?
Wedge-shaped opacity
Sign of PE on ECG?
Sinus tachycardia
S1Q3T3 pattern - rare
What is S1Q3T3?
Indication of acute cor pulmonale, and can sometimes be seen in PE due to right heart strain
S wave in lead I, a Q wave in lead III, and an inverted T wave in lead III
How to investigate PE?
Wells’ score - pre-probability test
CTPA
What is the Wells’ score?
CHHAMP
Clinical signs and symptoms of DVT (minimum of leg swelling and pain with palpation of the deep veins) = 3 HR > 100 = 1.5 Haemoptysis = 1 An alternative diagnosis is less likely than PE = 3 Malignancy (on treatment, treated in the last 6 months, or palliative) =1 Previous DVT/PE = 1.5 Immobilisation for > 3 days/surgery in the previous 4 weeks = 1.5
How is Wells’ score used?
If score >4 = PE likely –> CTPA
If score ≤ = PE unlikely –> D-dimer
How is CTPA used?
If CTPA positive = PE diagnosed
If CTPA negative = if DVT suspected do leg US. If DVT not suspected no PE
How is D-dimer used?
D-dimer positive = do CTPA
D-dimer negative = no PE
What should be started if PE is suspected?
Therapeutic anticoagulation
When is V/Q scan used instead of CTPA?
Pregnancy - lower radiation
Contrast allergy
Renal impairment
