Pulmonary Embolism Flashcards
How does thrombosis differ from haemostasis?
thrombosis occurs within the vessel while physiological haemostasis occurs outside the vessel wall as a result of injury
What are the the factors that influence thrombosis according to Virchow’s triad?
1) changes in blood flow (stasis or turbulence)
2) vessel wall dysfunction
3) changes in blood components, leading to hypercoagulability
Are venous thrombi red or white?
Red - rich in red blood cells and fibrin
Are arterial clots red or white?
White - rich in platelets
What is the most common cause of PE?
DVT
Other than a DVT, give 3 other sites where thrombi can originate to cause a PE:
1) upper limb
2) cerebral venous sinuses
3) splanchnic veins (hepatic, portal and mesenteric)
Give 12 risk factors for venous thromboembolisms:
1) surgery
2) coagulation disorders
3) immobilisation (bed rest >3 days)
4) age
5) trauma
6) recent long haul travel
7) acute medical admission
8) obesity
9) pregnancy
10) ethnicity
11) combined oral contraceptive/ HRT
12) cancer
Give 7 clinical presentations associated with pulmonary embolism:
1) pleuritic chest pain
2) breathlessness
3) haemoptysis
4) tachypnoea
5) tachycardia
6) crackles and pleural rub on auscultation
7) syncope
What is the nature of the chest pain experienced in a PE?
pleuritic
What auscultation findings support diagnosis of a PE? (2)
- Crackles
- Pleural rub
Give two examination findings that support diagnosis of a pulmonary embolism:
- Raised JVP
- Right ventricular heave (seen in severe cases)
What is the gold standard investigate for PE?
CT pulmonary angiogram
Describe ECG findings that would support a diagnosis of PE:
right ventricular strain pattern: T wave inversion in the inferior and right precordal leads
Give 4 initial investigations that may be used to assess breathlessness associated with a PE:
1) ECG
2) CXR
3) ABG
4) Biomarkers of cardiac injury such as BNP and troponin
What is the name of the risk calculator scoring system for PE?
Well’s Score
A score over how many points makes a PE ‘likely’ according to the Wells score?
> 4
Summarise the Wells Score criteria for pulmonary embolism risk:
1) signs and symptoms of DVT - 3 points
2) alternative diagnosis less likely than PE - 3 points
3) HR > 100 bpm - 1.5 points
4) immobilisation (>3 days) or surgery - 1.5 points
5) previous DVT/PE - 1.5 points
6) haemoptysis - 1 point
7) malignancy - 1 point
What investigation is used for patients deemed to be “PE unlikely” according to the Wells score?
D-dimer
Give 5 instances other than VTE where D-dimer may be raised:
1) advanced age
2) infection
3) inflammation
4) cancer
5) pregnancy
True or false: if Wells score verdict is “PE unlikely” but D-dimer is raised, you should still ensure the patient has a CT scan
true
Give an alternative to CTPA for investigation of PEs:
ventilation-perfusion isotope lung scanning
Describe the two phases of ventilation-perfusion isotope lung scanning:
1) perfusion phase - radio-labelled albumin is injected IV and used to access blood flow to the lung
2) ventilation phase - patients inhale radio labelled xenon to access air delivery to the lungs
Fill in the gap: diagnostic testing for suspected PE should be performed urgently and completed within __ hrs of the initial presentation
24
What is the initial treatment for PEs?
parenteral anticoagulants (Oral liquid)
