Pulmonary Embolism Flashcards
Define Pulmonary Embolism?
Occlusion of pulmonary vessels, most commonly by a thrombus that has travelled to the pulmonary vascular system from another site
What is the aetiology of Pulmonary Embolism?
Thrombus
95% arise from DVT in the lower limbs
Rarely arises in the right atrium (in AF patients)
What are some other causes of embolus?
Amniotic Fluid Air Fat Tumour Mycotic
What are the risk factors for PE?
Surgical patients Immobility Obesity OCP Heart Failure Malignancy
What is the epidemiology of Pulmonary Embolism?
Relatively common (especially in hospitalised patients) Occur in 10-20% of patients with confirmed proximal DVT
What does the presenting symptoms of Pulmonary Embolism depend on?
Site and Size of the embolus
What are the presenting symptoms of a small Pulmonary Embolism?
May be asymptomatic
What are the presenting symptoms of a moderate Pulmonary Embolism?
Sudden-onset SOB
Cough
Haemoptysis
Pleuritic Chest Pain
What are the presenting symptoms of a large (or proximal) Pulmonary Embolism?
Same as moderate and: Severe central pleuritic chest pain Shock Collapse Acute Right Heart Failure Sudden Death
What are the presenting symptoms of Multiple Small Recurrent Pulmonary Embolisms?
Symptoms of pulmonary hypertension
How can the severity of a Pulmonary Embolism be assessed?
Based on associated signs
What are the signs of a small Pulmonary Embolism on physical examination?
Often no clinical signs
There may be some tachycardia and tachypnoea
What are the signs of a moderate Pulmonary Embolism on physical examination?
Tachypnoea
Tachycardia
Pleural rub
Low O2 saturation (despite O2 supplementation)
What are the signs of a massive Pulmonary Embolism on physical examinaton?
Shock
Cyanosis
Signs of right heart strain
What are the signs of right heart strain?
Raised JVP
Left parasternal heave
Accentuated S2 heart sound
What are the signs of Multiple Recurrent Pulmonary Embolism on physical examination?
Signs of pulmonary hypertension
Signs of RH failure
How do you determine the best investigation for Pulmonary Embolism?
Well’s Score
How is the Well’s Score used?
Low Probability (Wells 4 or less) - Use D-Dimer High Probability (Wells > 4) - required imaging (CTPA)
What bloods would you do for a Pulmonary Embolism?
ABG
Thrombophilia screen
What might you see on an ECG in Pulmonary Embolism?
May be normal
May show tachycardia, right axis deviation or RBBB
May show S1Q3T3 pattern
Why do we do a CXR for Pulmonary Embolism?
Often normal but helps exclude other diagnoses
How do we use Spiral CT Pulmonary Angiogram in Pulmonary Embolism?
First Line Investigation
Poor sensitivity for small emboli
Very sensitive for medium to large emboli
How do we use Ventilation-Perfusion (VQ) scan in Pulmonary Embolism?
Identifies areas of ventilation and perfusion mismatch which would indicate an area of infarcted lung
Why do we not use Pulmonary Angiogram for Pulmonary Embolism?
Invasive
Rarely necessary
Why do we use Doppler US of Lower Limb in Pulmonary Embolism?
Allows assessment of venous thromboembolism
What might you see on Echocardiography on Pulmonary Embolism?
May show right heart strain
What is the primary prevention of Pulmonary Embolism?
Compression Stockings
Heparin prophylaxis for those at risk
Good mobilisation and adequate hydration
What do we do if a patient with Pulmonary Embolism is haemodynamically stable?
O2 Anticoagulation with heparin or LMWH Switch over to oral warfarin for at least 3 months Maintain INR 2-3 Analgesia
What do we do if a patient with Pulmonary Embolism is haemodynamically unstable (massive PE)?
Resuscitate
O2
IV fluids
Thrombolysis with tPA may be considered if cardiac arrest is imminent
What is the surgical and radiological management of Pulmonary Embolism?
Embolectomy
IVC filters - sometimes used for recurrent PEs despite adequate anticoagulation or when anticoagulation is contraindicated
What are the possible complications of Pulmonary Embolism?
Death
Pulmonary Infarction
Pulmonary Hypertension
Right Heart Failure
What is the prognosis for patients with Pulmonary Embolism?
30% mortality in those left untreated
8% mortality with treatment
Increased risk of future thromboembolic disease
