Pulmonary Embolism

Question 1

What is a pulmonary embolism (PE)?

Answer 1

A pulmonary embolism is the obstruction of one or more pulmonary arteries by a blood clot, air, fat, or amniotic fluid, most commonly caused by a thrombus.

Question 2

What are the common symptoms of PE?

Answer 2

Symptoms include sudden onset breathlessness, pleuritic chest pain, and haemoptysis.

Question 3

What are the common signs of PE on examination?

Answer 3

Signs include tachypnoea, tachycardia, hypoxia, hypotension, and possibly a raised jugular venous pressure (JVP).

Question 4

What is the most common cause of PE?

Answer 4

The most common cause is a thrombus, often originating from a deep vein thrombosis (DVT).

Question 5

What is the pathophysiology of PE?

Answer 5

A clot obstructs a pulmonary artery, causing impaired gas exchange, increased pulmonary vascular resistance, and potential right heart strain or failure.

Question 6

What are the risk factors for PE?

Answer 6

Risk factors include immobility, surgery, malignancy, pregnancy, hormone replacement therapy, and inherited thrombophilia (e.g., Factor V Leiden).

Question 7

What are the components of Virchow’s triad?

Answer 7

The components are endothelial injury, venous stasis, and hypercoagulability.

Question 8

What is the prevalence of PE?

Answer 8

PE is relatively common, with an estimated incidence of 60-70 cases per 100,000 people annually.

Question 9

What is the clinical significance of a massive PE?

Answer 9

A massive PE causes significant obstruction of blood flow, leading to haemodynamic instability, shock, or cardiac arrest.

Question 10

How is a PE diagnosed?

Answer 10

Diagnosis is based on clinical assessment, risk stratification (e.g., Wells score), and imaging such as CT pulmonary angiography (CTPA) or ventilation-perfusion (V/Q) scan.

Question 11

What is the Wells score?

Answer 11

The Wells score is a clinical prediction tool to estimate the probability of PE based on factors like clinical signs of DVT, heart rate, and history of immobility or malignancy.

Question 12

What investigations are used to confirm a PE?

Answer 12

Investigations include CTPA, D-dimer test, V/Q scan, arterial blood gas analysis, and ECG.

Question 13

What are typical ECG findings in PE?

Answer 13

ECG may show sinus tachycardia, right ventricular strain pattern, or the S1Q3T3 pattern.

Question 14

What are the key findings of a PE on a chest X-ray?

Answer 14

A chest X-ray may be normal or show signs such as wedge-shaped opacity (Hampton’s hump) or pleural effusion.

Question 15

What is the role of D-dimer testing in PE?

Answer 15

D-dimer testing is used to exclude PE in low-risk patients, as a negative result makes the diagnosis unlikely.

Question 16

What are the differential diagnoses for PE?

Answer 16

Differential diagnoses include myocardial infarction, pneumonia, pneumothorax, pericarditis, and heart failure.

Question 17

What is the acute medical management of PE?

Answer 17

Acute management includes oxygen therapy, anticoagulation (e.g., low molecular weight heparin or direct oral anticoagulants), and thrombolysis for massive PE.

Question 18

What is thrombolysis in the context of PE?

Answer 18

Thrombolysis involves using medications such as alteplase to dissolve the clot, typically reserved for haemodynamically unstable patients.

Question 19

What are the long-term management options for PE?

Answer 19

Long-term management includes anticoagulation therapy (e.g., warfarin, DOACs) and addressing underlying risk factors.

Question 20

When is an inferior vena cava (IVC) filter used in PE?

Answer 20

IVC filters are used to prevent further emboli in patients who cannot tolerate anticoagulation or have recurrent emboli despite treatment.

Question 21

What lifestyle modifications are recommended to prevent PE?

Answer 21

Modifications include regular physical activity, staying hydrated, avoiding prolonged immobility, and smoking cessation.

Question 22

What are the indications for thrombophilia testing in PE?

Answer 22

Testing is indicated in patients with recurrent unprovoked PEs or a strong family history of thrombosis.

Question 23

What is a saddle embolus?

Answer 23

A saddle embolus is a large clot that straddles the bifurcation of the pulmonary trunk, obstructing both main pulmonary arteries.

Question 24

What is chronic thromboembolic pulmonary hypertension (CTEPH)?

Answer 24

CTEPH is a long-term complication of PE where unresolved clots lead to increased pulmonary artery pressure and right heart strain.

Question 25

How can PEs be prevented in hospitalised patients?

Answer 25

Prevention includes thromboprophylaxis with low molecular weight heparin, mechanical methods like compression stockings, and early mobilisation.