Pulmonary Embolism

Question 1

Define pulmonary embolism

Answer 1

Occlusion of the pulmonary vessels often by an embolus from a deep vein thrombus

Question 2

What are the causes/risk factors of PE?

Answer 2

Causes
• Thrombus (mostly DVT, also AF)
• Amniotic fluid
• Air
• Fat
• Tumour
• Mycotic

Risk Factors
• Surgery
• Immobility
• Obesity
• OCP
• Malignancy
• Previous/FH of VTE

Question 3

What are the presenting symptoms of PE?

Answer 3

• Asymptomatic
• Sudden onset SOB
• Cough
• Haemoptysis
• Pleuritic chest pain

Question 4

What are the signs of a PE?

Answer 4

• Tachycardia
• Tachypnoea
• Pleural rub
• Low O2 sats
• Leg/calf swelling/tenderness

Massive PE
• Shock – hypotension
• Cyanosis
• CV collapse
• Acute right heart failure – raised JVP, RV heave, accentuated S2
• Sudden death

Question 5

What are the investigations for PE?

Answer 5

• Well’s score
o <4 = unlikely -> proceed to D-dimer
o >4 = likely -> proceed to imaging
• D-dimer (sensitive but non-specific)
o Normal – excludes PE if Well’s score is also <4
o Elevated – proceed to imaging
• CTPA – 1st line, contraindicated in pregnancy, renal
insufficiency
• V/Q scan – inappropriate if there is co-existing lung
disease
• MR angiography – direct visualisation of thrombus

Other
• Bloods
o Thrombophilia screen
• ABG – hypoxia
• ECG – tachycardia, RBBB, RAD, S1 Q3 T3
• CXR
o Usually normal
o Westermark’s sign – oligaemia
(hyperlucent)
o Hampton’s hump – increased opacity
o Fleischner’s sign – prominent central pulmonary artery
o Exclude other differentials
• Echocardiogram – right ventricular strain
• Duplex USS of lower limb – look for DVT

Question 6

What is the management for PE?

Answer 6

Haemodynamically stable
• O2
• Analgesia
• Anticoagulation with IV unfractionated heparin or SC LMWH
• Oral warfarin therapy for >3months (target INR 2-3)

Haemodynamically unstable
• O2
• IV fluids
• Thrombolysis with tPA
• Anticoagulation with IV unfractionated heparin or SC LMWH
• Oral warfarin therapy for >3months (target INR 2-3)

Surgical
• Embolectomy
• IVC filter for recurrent PE

Question 7

What are the complications of PE?

Answer 7

• Cardiac arrest ->death
• Recurrent VTE
• Pulmonary infarction
• Pulmonary hypertension
• Right heart failure