Thromboembolic disease: PE (R1) Flashcards
Pathophysiology of PE?
- Usually arises from embolisation of DVT
- Blockage in the pulmonary arteries –> capillaries
- Impaired gas exchange leads to hypoxia and hypercapnia. This stimulates drive to breathe (SOB)
- Also leads to pulmonary infarction
Complications
- 3 acute complications?
- Is there a high risk of recurrence?
Shock: less blood reaches left ventricle –> reduced CO
Acute cor pulmonale: increased resistance in pulmonary arteries …
Death
Yes, there is a high risk of recurrence.
History:
- Symptoms of PE?
Pleuritic chest pain
SOB (may only be exertional!)
Cough +- haemoptysis
Palpitations
Syncope/fainting
Exam
- Vitals?
- Importance of taking exertional vitals in PE?
- Are there additional exam findings in your notes?
↑HR, ↑ RR, ↓BP, ↓ PO2
Potentially ↑ temperature - if infection related
Yes - some people may only show vitals on exertion
Yes
Investigations
- Bedside: supportive test?
ECG
Investigations
- Bedside: ECG
What may it show?
- Most common: sinus tachycardia
- May be normal
- Signs of right heart strain
- S1 Q3 T3 (uncommon):
- S1: deep S waves in lead I
- Q3: deep Q waves in lead III
- T3: T wave inversion in lead III
Investigations: labs
- Smoking gun?
D dimer
Investigations: D dimer
- When should it be used?
- What to do if you get a positive result?
If there is a moderate to high probability of PE
Go straight to imaging
Investigations: labs
- What supportive tests?
Baseline FBC, UEC, LFT, coagulation studies
Troponin: may be a low grade rise
ABG: if low PO2
Investigations: imaging
- What are the 2 modalities?
CT pulmonary angiogram
VQ scan
Investigations: imaging
- What is the finding of PE in each?
- Why might a VQ scan be used instead of a CT PA?
CT PA: filling defects
VQ scan: area of ventilation that is not perfused
VQ scan would be used if:
- The patient has poor lung function (smoker, COPD etc)
- Pregnant
- Renal impairment or contrast allergy
Management
- If hemodynamically unstable?
Management
- Ongoing management?
Anticoagulants
- DOACs: apixaban and rivaroxaban (factor Xa inhibitors)
- LMWH : enoxaparin (Clexane) - if contraindicated to the above
Management: ongoing
- Timing of anticoagulation if the PE is unprovoked versus provoked?
Provoked: can usually stop anticoagulants after 3 months
Unprovoked: ongoing
Management:
Treatment if contraindicated to anticoagulants, or recurrent VTE despite adequate anticoagulation therapy?
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