Lecture 11-Pulmonary Embolism Flashcards
What is a pulmonary embolism?
Thrombus enters right side of the heart and pulmonary arteries
What are the risk factors for pulmonary embolism?
- age > 40
- surgery
- obesity
- cancer
- immobilisation
- heart failure
- contraceptive pill
- pregnancy
- long haul flight
- thrombophilia
What are the outcomes of pulmonary embolism?
Sudden death -> asymptomatic
What puts a patient at a high risk of PE?
Shock or hypotension
How can RV overload lead to PE?
- pulmonary artery pressure rises -> RV dilatation and strain
- inotropes are released to maintain systemic BP -> pulmonary artery vasoconstriction
- some have patent foramen ovale -> right to left shunt -> severe hypoxaemia and incresaed risk of stroke
What is the main cause of death in PE?
Pulmonary artery vasoconstriction
How can a pulmonary infarction cause a PE?
Small distal emboli may create alveolar haemorrhage -> haemoptysis, pleuritis and pleural effusion
What are the symptoms of PE?
Dyspnoea, pleuritic chest pain, cough, substernal pain, fever, haemoptysis, syncope, unilateral leg pain
What are the differential diagnoses for PE?
- MI
- pneumothorax
- pneumonia
Which investigations can be done to confirm PE?
- CXR (normal in PE, done to exclude other diagnoses)
- ECG (T wave inversion)
- Blood gases
- D dimer (normal rules out PE)
- imaging
- Well’s score for predicting likelihood
What is a D-dimer?
Fibrin degradation product, small protein fragment released into blood when thrombus is degraded by fibrinolysis
What is the immediate treatment for PE?
Heparinisation - stops thrombus propagation in pulmonary arteries and allows body’s fibrinolytic system to lyse thrombus
What is the treatment for high risk PE patients?
- haemodynamic and resp support
- exogenous fibrinolytics via catheter
- percutaneous catheter directed thrombectomy
- surgical pulmonary embolectomy
After initial heparinisation, what are patients given?
- oral warfarin for 3 months if temporary risk factor
- oral warfarin indefinitely if cancer or no identifiable risk factor
How are patients who can’t be safely coagulated treated? (eg patients with oesophageal varices, previous haemorrhagic stroke etc)
Umbrella in vena cava so clots can’t reach heart, inserted through jugular vein
