Pulmonary Embolism Flashcards
What is a typical presentation of a patient with a pulmonary embolism?
Tachycardia
Tachypnoea
Hypotension
Sharp sudden onset chest pain
Haemoptysis
Syncope
Hypoxia
Low grade fever
AF
Signs of DVT
What investigations would you do for a patient with pleuritic chest pain and acute SOB?
D-DIMER
ECG
FBC
ABG on air
What are the risk factors for developing a PE?
Immobility
Long haul flights
Pregnancy
Combined oral contraceptive (oestrogen containing)
Malignancy
Recent surgery
Polycythaemia
Systemic Lupus Erythematous
Thrombophilia
Nephrotic syndrome
What is the importance of D-dimer for investigating ?PE?
If D-dimer is not elevated then can rule out Pulmonary embolism
However if its elevated it does not mean its a PE can be other causes
What are some causes of raised D-dimer?
Pulmonary embolism
Aortic dissection
Disseminated Intravascular Coagulation
Pneumonia
Malignancy
Pregnancy
Heart failure
Surgery
What are some causes of raised D-dimer?
Pulmonary embolism
Aortic dissection
Disseminated Intravascular Coagulation
Pneumonia
Malignancy
Pregnancy
Heart failure
Surgery
What is the best term to describe D-dimers for its diagnostics for PE?
Highly sensitive but not specific or Highly specific but not sensitive?
Highly sensitive but not specific
What imaging methods are diagnostic for pulmonary embolism?
CTPA
V/Q scan
(Need to do CXR before requesting a CTPA)
What is considered a raised D-dimer?
If its more than x10 their age
What are CTPAs good at identifying?
Large/massive pulmonary emboli that are in the main pulmonary arteries
What are V/Q scans good at identifying?
Smaller pulmonary emboli that aren’t in the large pulmonary arteries and are in the pleura
Why do we not just CTPA every patient with ?PE?
High radiation dose
Nephrotoxic contrast dye
What is Pa02?
How can you find this out?
Oxygen saturations in the arteries
Find from ABG
What is PA02?
How do you find this out?
Oxygen saturation in the alveoli
PA02 equation
What is the equation to work out PA02?
(Alveolar oxygen saturation)
PA02 = atmospheric pressure of 20 - (pCO2)/0.8
What is the relevance of having both PO2a and PO2A?
Can work out the alveolar arterial gradient
What is the significance of being able to calculate an Aa gradient (alveolar arterial gradient)?
Can give an indication of impaired ventilation perfusion ratio
What is a permissible Aa gradient?
Can have 1 point of Aa gradient per decade of life
24 year old can have a score of 2.4 and be fine
(Shouldn’t really be a gradient)
Why would you lean towards doing a V/Q scan rather than a CTPA?
Patient has pleuritic chest pain, slightly hypoxic, slightly elevated d-dimer and relatively normal Aa
How can you reduce a patients risk of VTEs in hospital?
LMWH (enoxaparin)
TED stockings
Mobilising.
What are the classifications for Pulmonary embolisms?
High risk (massive)
Intermediate high risk (sub massive)
Intermediate low risk
Low risk
What is the scoring system used to determine severity of pulmonary embolism?
PESI prognostic score
Pulmonary Embolism Severity Index
Why is it always important to ask a patient if they lost consciousness when they had SOB and pleuritic chest pain?
Likely indicates a massive PE
What medication do you give to a patient with ?PE?
DOAC like Apixaban or Rivaroxaban but can Always give Anticoagulation ENOXAPARIN even if patient is pregnant (LMWH) while waiting for diagnosis
If its severe want to give thrombolysis
What is an example of a drug for thrombolysis in a patient with a massive PE?
Alteplase
Why do we not give thrombolysis to every patient with a PE?
High risk of bleeding and high risk of death
Who should you give thrombolysis to when they have a PE?
PESI class III, IV and V
When theres RV. Dysfunction
How does 30day risk of mortality from lysis change as PESI score gets higher?
30 day lysis mortality Doesnt. Change with PESI score, it’s alway 1.8%
When is thrombolysis contraindicated?
Active bleeding
Recent haemorrhagic stroke
Would you thrombolyse (alteplase) a patient with an intermediate high risk PE?
Yes if they have either RV dysfunction or myocardial necrosis
What are some ECG changes that might be visible in a PE patient?
S1Q3T3
Sinus tachycardia
Other signs of right sided heart strain
T wave inversion in V1-V3
T wave inversion II,III, avF (right ventricle)
Right axis deviation
RBBB
What are some heart changes that you might be able to see on CTPA?
R heart dilatation
Septal flattening
Tricuspid regurgitation
RV or RA thrombus
What are some heart changes that you might be able to see on CTPA?
R heart dilatation
Septal flattening
Tricuspid regurgitation
RV or RA thrombus
What are some heart changes seen on Echocardiogram with PE?
RV enlargement
Tricuspid regurgitation
Right heart thrombus
What are some relative contraindications for thrombolysis in patients with intermediate PESI score?
TIA in last 3 month
Existing anticoagulants with warfarin
Traumatic CPR
Generally, how do you manage a PE?
Oxygen?
Analgesia?
Monitor for deterioration
Enoxaparin
? Thrombolysis (alteplase) if massive PE
Give long term VTE like DOACs (apixaban, rivaroxaban)
Warfarin if DOACs not suitable
When do you not give DOACs (apixaban) to a patient as VTE prophylaxis?
Renal impairment
Pregnancy
Antiphospholipid syndrome
What long term VTE can be given to a pregnant lady?
LMWH
What is the first line medication given to patients as VTE prophylaxis with antiphospholipid syndrome?
Warfarin
How long is apixaban or enoxaparin given for a provoked PE (known cause)?
How long is enoxaparin or apixaban given for an unprovoked PE (unknown cause)?
Known = 3months
Unknown = 6 months
What is a paradoxical embolus?
Embolism enters into arterial system via a pateitn foramen ovale leading to stroke/cerebral ischaemia
What are the 3 factors of Virchows triad?
Stasis of blood
Vessel wall injury
Hypercoagulability
Why can a pulmonary embolism lead to right heart failure?
Embolism leads to increased afterload of the right ventricle
What scoring system should you do to assess likelihood of PE?
Wells score
What is your management approach if a patient has a low wells score?
Do a D-dimer test
If positive then do definitive diagnostic test like CTPA or V/Q perfusion scan
What is the management of a patient with a high wells score?
Don’t need to do D-dimer score can just do definitive diagnostic test like CTPA or V/Q perfusion scan
What are some coagulation conditions that contraindicates Anticoagulation?
Factor V Leiden
Protein C or S defects
Haemophilia A and B
