9.5 Pulmonary Embolism Flashcards
Describe pulmonary embolism
Obstruction of pulmonary artery (or branch of) by thrombus created elsewhere in the body
Describe sub-massive pulmonary embolism
- Haemodynamically stable
- SBP > 90 and right ventricular dysfunction
Describe massive pulmonary embolism
- Haemodynamically unstable
- Sustained hypotension (<SBP <90 for 15min)
- Requiring ionotropic support
- Pulselessness
- Sustained HR < 40bpm and symptoms of shock
(Any of these)
How many patients develop venous thromboembolism (VTE) annually in Australia.
17,000
What types of patients have increased risk of developing VTE?
- Hospitalised
- Pregnancy
Virchow’s triad describes three factors that increase risk of clot formation. What are they?
- Stasis
- Hypercoagulable state
- Vessel wall injury
List an inherited risk factor for pulmonary embolism
Genetic clotting disorders
List some acquired risk factors for pulmonary embolism (including those that provoke clots and those that don’t)
Provoking clot formation (provoked PE):
- Immobilisation
- Cancer
- Recent surgery/trauma
Other RF:
- Smoking
- Obesity
List three consequences of a thrombus lodging in pulmonary arteries during pulmonary embolism
- Infarction (reduced flow due to clot)
- Abnormal gas exchange (less blood flow for gas exchange due to clot, resulting in hypoxia)
- Increased pulmonary vascular resistance -> right ventricular dysfunction and compromised cardiac output
What are the clinical symptoms of pulmonary embolism?
- Dyspnoea
- Pleuritic chest pain
- Leg swelling and pain if DVT
- Dizziness
- Haemoptysis
What are the clinical signs of pulmonary embolism?
- Tachypnoea
- Hypoxia
- Tachydardia
- Hypotension
- Elevated JVP
- If DVT: oedema and calf tenderness
Provoked vs unprovoked pulmonary embolism
- Provoked: caused by certain risk factors
- Unprovoked: no apparent risk factors
What are some important points in a patient’s history regarding pulmonary embolism?
- Previous VTE
- FHx VTE or miscarriage (? genetic condition)
- Provoking factors (cancer, smoking, obesity, recent immobilisation)
Link between pulmonary embolism and miscarriage
- Thrombophilia (increased tendency to form clots)
- Increased PE risk, and clot may occlude maternal artery
Relationship between Wells score and D dimer requirement
- If you think it is very likely to be PE, and your Well’s score is >4, no need for D Dimer
- If less than four, but you’re still unsure, do a D Dimer
