Pulmonary Embolism Flashcards
What is a pulmonary embolism?
A blood clot that forms and gets lodged in the pulmonary artery.
Where does. PE usually originate from, what’s its journey?
Originates - DVT in leg.
Journey - travels through the venous system, through the right side of the heart and into pulmonary arteries before getting stuck.
Which side of the heart is mostly affected by a PE?
The right side - there is increased strain on right side pumping blood to the lungs.
What do the pulmonary arteries carry?
Low O2
High CO2
blood - travelling in lungs to give off CO2 and get more O2.
What is VTE?
Venous thromboembolism = Pulmonary embolism + Deep vein thrombosis.
What are the risk factors of VTE?
Immobility Recent surgery Long haul flights Pregnancy Cancer Oestrogen hormone therapy High haemoglobin Inflammatory conditions Thrombophilia conditions
What are examples of oestrogen therapy causing risk of VTE?
Oral combined contraceptive pill
Hormone replacement therapy
What are examples of inflammatory conditions causing risk of PE?
Systemic lupus erythematosus.
What are thrombophiliac conditions causing risk of VTE?
Thrombophilia = your blood can form clots too easily.
Antiphospholipid syndrome.
What are the signs/symptoms of PE?
Pleuritic chest pain (sharp pain on deep breathing) SOB Collapse Cough - with or without blood Hypoxia Tachycardia Increased Respiratory rate Fever Haemodynamically unstable Hypotension Cardiogenic shock
What is haemodynamic shock?
A perfusion failure - causing low blood pressure - where blood ends up not being able to perfuse the organs.
What are the signs/symptoms of a DVT?
Unilateral pain and/or swelling in leg
What is the prophylaxis for VTE?
Injection of low molecular weight heparin. Done if suspected before results.
Compression socks
What are the contraindications of low molecular weight heparin?
Pregnancy
Active bleeding
Use of existing anticoagulants
What are the contraindications of compression socks?
Peripheral arterial disease.
Which score indicates the likeliness of a PE?
WELLS Score.
What test is done to investigate a PE?
PE likely - CT pulmonary angiogram.
PE unlikely - D-dimer (if this is +, do a CTPA).
What is true about eh D dimer test?
95% sensitive but NOT specific.
What causes a positive D dimer result?
PE recent surgery heart failure pregnancy Pneumonia
What is a CTPA?
CT pulmonary angiogram - Chest CT using an IV contract.
1st choice.
What are the two imaging tests that can be done?
CTPA
Ventilation perfusion scan.
What is a VQ scan?
Isotopes are inhaled and picture of lungs is taken.
Isotopes are given IV and picture is taken.
Pictures compared - there is a part of the lungs not being perfused due to blood blockage.
- Scan will show higher ventilation and lower perfusion.
What does an ABG show?
Respiratory alkalosis - Low O2 causes a high respiratory rate - Blow off too much CO2 and can’t get any new oxygen.
Low O2
Low CO2
What are the causes of respiratory alkalosis?
Pulmonary embolism - Low O2, low CO2.
Hyperventilation - High O2, low CO2.
What is long term treatment?
Initial = Low molecular weight heparin.
Warfarin
DOACS - direct acting oral coagulants
Low molecular weight heparin
What are the names of heparin?
Enoxaparin.
What is the target INR dose when using warfarin?
INR between 2-3.
What should be done if long term warfarin is started?
Continue with the initial low weight molecular heparin for first 5 days (or until INR it stable).
What are examples of the DOACS?
Riveroxaban
Apixaban
Dabigatran
Who should take low molecular weight heparin as a long term choice?
Pregnant women
People with cancer
What is thrombolysis?
Injecting a thrombolytic medication (streptokinase, alteplase, tanectoplase) either IV or directly into the pulmonary arteries.
It breaks down fibrin.
