Pulmonary Embolism Flashcards
What is pulmonary embolism and what does it cause
When a blood clot ( thrombus ) forms in the pulmonary arteries that blocks blood flow to lung tissue and causes a strain on RS of heart
What usually causes pulmonary embolism
A deep vein thrombosis in the legs that travelled through the venous system and the right side of heart to pulmonary arteries a
List the risk factors for pulmonary embolism or DVT ( Hint : 9 )
1- Immobility 2- Recent surgery 3- Long haul flights 4- Pregnancy 5- hormone therapy with oestrogen 6- malignancy 7- Polycythaemia 8- Systemic lupus erythematoosus 9- Thromophilia
What is VTE
Venous thromboembolism
What prophylactic treatment is given to reduce risk of PE or DVT
Low molecular weight heparin
What treatment is given to someone at increased risk of VTE ( give drug name example )
1- low molecular weight heparin such as enoxaparin
2- Anti-embolic oppression stockings
What contraindicates low molecular weight heparin
1- Active bleeding
2- existing coagulation with warfarin
3- NOAC
What is a contraindication of compression stockings
Significant peripheral arterial disease
How does a patient with PE present ( Hint : 8)
1- SOB 2- Cough with or without blood 3- Pleuritic chest pain 4- Hypoxia 5- Tachycardia 6- Raised respiratory rate 7- Low grade fever 8- Haemodynamic instability causing hypotension
What are signs specific to DVT
Unilateral leg swelling and tenderness
What is Well’s score
Score that predicts the risk of a patient presenting with PE/DVT symptoms actuating having PE/DVT
For diagnosing a PE what is the NICE recommendations of assessment for alternative causes
1- History
2- Examination
3- Chest Xray
What is the next step if Wells score is likely
Preform a a CT pulmonary angiogram
What is the next step if Wells score is Unlikely
preform d-dimer and if positive preform CTPA
What are the two options to establish a definitive diagnosis of PE
1- CT pulmonary angiogram (CTPA)
2- Ventilation-perfusion scan ( VQ)
Describe how a CTPA works
Chest scan with intravenous contrast that will highlight pulmonary arteries and thus show any blood clots.
Describe how VQ scans work
A radioactive isotope and gamma camera are used to compare ventilation with perfusion of lungs. Isotopes are inhaled to fill lungs and picture is taken demonstrating ventilation. Contrast containing isotope is then injected and picture is taken showing perfusion. Two pictures are compared.
How will a PE present in a VQ scan
There will be a deficit in perfusion since thrombus blocks blood flow to lung tissue. Area will be well ventilated.
In which patients are VQ scans used
1- renal impairment
2- contrast allergy
3- at risk from CTPA radiation
Why is a CTPA used more than VQ scan
1- more readily available
2- provides more definitive assessment
3- gives info about alternate diagnosis such as pneumonia or malignancy
What will the ABG of a patient with PE likely show
Respiratory Alkalosis because high respiratory rate results in low CO2. There will also have low pO2
What is the difference between the ABG of PE patient and hyperventilation syndrome patient
PE patient will have low p02 wile hyperventilation patient will have a high p02
What is the supportive management for VTE
1- admission to hospital
2- oxygen
3- analgesia
4- monitoring for deterioration
What is the initial management of VTE
1- Apixaban or rivaroxaban
2- Low molecular weight heparin if step 1 not suitable
When should initial management be started if PE or DVT is suspected
Treatment should start immediately even if diagnosis is not confirmed yet
What is the long term management for VTE
Long term anticoagulation treatment, options:
1- warfarin
2- NOAC
3- LMWH
What is the procedure of switching from LMWH to warfarin
Continue LMWH for 5 days when switching to warfarin or until the INR is 2-3 for 24 hours
What are the three options for NOAC ( DOAC )
1- apixaban
2- dabigatran
3- rivaroxaban
What is the long term first line treatment for VTE if patient is pregnant or has cancer
LMWH
How long should the long term anticoagulation management continue ( Hint: 3 possible situations )
1- 3 months if there is a reversible cause
2- 3+ months if cause is unclear and VTE is recurrent OR irreversible cause
3- 6 months in active cancer
What is Thrombolysis
A treatment that involves injecting a fibrinolytic medication to rapidly dissolve clot
When is thrombolysis used
When there is a large PE with haemogynamic compromise
What is the risk with Thrombolysis
Significant risk of bleeding
List examples of thrombolytic agents
1- Streptokinase
2- Alteplase
3- Tenecteplase
What are the 2 ways thrombolysis can be preformed
1- IV with peripheral cannula
2- Directly into pulmonary arteries using central catheter
Explain how a catheter directed thrombolysis works
Catheter is inserted into venous system through the right side of heart and into pulmonary arteries. Thrombolytic agent is administered directly into location of thrombus.
What is the risk with using equipment to physically break down thrombus
Risk of damaging pulmonary arteries
