Pulmonary embolism Flashcards
What type of embolism is a pulmonary embolism?
Thromboembolism
Where does the thrombus usually arise from in pulmonary embolism?
Deep vein in leg
particularly the popliteal vein, iliac veins
What is the name of the condition of a thrombus in a deep vein in the leg?
Deep vein thrombosis (DVT)
How does a small pulmonary embolism present?
Asymptomatic
How do multiple small pulmonary emboli present?
Pulmonary hypertension
Right ventricular failure
Why do multiple small pulmonary emboli cause pulmonary hypertension?
Block pulmonary arteries
increases pressure in pulmonary arteries
Why do multiple small pulmonary emboli cause right venticular failure?
Right ventricle has to contract harder to generate higher pressures to push blood through pulmonary circulation
suffers volume overload
How do large pulmonary emboli present?
Pleuritic chest pain
Dyspnoea
Pleural rub
Raised JVP
What investigations are done when a patient is suspected to have a pulmonary embolism?
Chest X-ray
ECG
Blood gases
D-dimer
CT scan
What does a chest X-ray of a patient with a pulmonary embolism look like?
Normal
What does an ECG of a patient with a pulmonary embolism look like?
Right chest leads - T wave inversion
S1 Q3 T3
What is S1 Q3 T3?
Lead 1 - deep S wave
Lead 3 - deep Q wave, inverted T wave
What are the levels of blood gases of a patient with a pulmonary embolism?
Hypoxia
Hypocapnia
Why do patients with pulmonary embolism have hypocapnia?
Respiratory alkalosis
due to hyperventilation
What are the levels of D-dimers in the blood of a patient with a pulmonary embolism?
Patient who’s never had a pulmonary embolism before - raised
Patient who’s had a pulmonary embolism before - normal or raised
How are pulmonary embolisms treated?
For all patients, oxygen immediately
For all patients, IV heparin immediarely
Only for high risk patients
- fibrinolytics
- thrombectomy, embolectomy
For all patients, oral anticoagulents or IVC filter long-term
How does immediate IV heparin treat a pulmonary embolism?
Stops the propogation of the thrombus in the pulmonary artery and also the source
What are some examples of fibrinolytics?
Streptokinase
Tissue plasminogen activator
How are fibrinolytics given?
IV
directed to pulmonary artery embolism by a percutanenous catheter
What is an example of an oral anticoagulant?
Warfarin
How long are patients who had a pulmomary embolism given oral anticoagulants for?
3 months if there was an identifiable risk factor
Forever if there was no identifiable risk factor, or if they have cancer
What is an IVC filter?
Filter in the IVC that presents the passage of thromboemboli from the lower body up to the heart
When is an IVC filter given to a patient who had a pulmonary embolism?
If they can’t be given anticoagulants
What is a paradoxical embolus?
Embolus passes from right atrium, through patent foramen ovale, into left atrium
What does a paradoxical embolus most commonly cause? How?
Stroke
travels from left atrium to blood vessel supplying the brain
How does a pulmonary embolism affect ventilation:perfusion?
Causes ventilation:perfusion mismatch
because alveoli are ventilated but not perfused
What is a saddle embolus?
Pulmonary embolism that lodges in the bifurcation of the pulmonary artery
