Condition- Pulmonary Embolism Flashcards
What is a pulmonary embolism?
Occlusion of pulmonary vessels, most commonly by a thrombus that has travelled to the pulmonary vascular system from another site
What is the main cause of pulmonary obstruction in pulmonary embolism and where does it tend to originate from?
Thrombus
- 95% arise from DVT in the lower limbs
- Rarely arises in the right atrium (in AF patients)
List some of the other causes of embolus in pulmonary embolism…
- Amniotic fluid
- Air
- Fat
- Tumour
- Mycotic
- Parasites
- Right ventricular thrombus (post MI)
- Septic emboli (right sided endocarditis)
List some risk factors for developing a pulmonary embolism…
- Surgical Patients
- Immobility- long haul flights, recent hospitalisation
- Malignancy
- Obesity
- Pregnancy
- Heart Failure
- OCP
- Thrombophilia
- Previous PE
- Genetic diseases: Factor V Leiden, Protein C/S deficiency, thrombophilia
The severity of the presentation of a patient with PE depends on the ………….. and ……….. of the embolus
The severity of the presentation of a patient with PE depends on the SITE and SIZE of the embolus
List the symptoms experienced by someone with a pulmonary embolism
- Pleuritic Chest pain- pain exacerbated by deep breathing, coughing, sneezing, or laughing
- SOB
- Cough
- Haemoptysis
- (signs of DVT- unilateral swelling of calf)
Describe the presentation of someone with a large or proximal embolus…
If Large or Proximal Embolus:
- Severe central crushing pleuritic pain
- Feelings of apprehension (sign of shock)
- Collapse
- Acute right heart failure
- Sudden DEATH
List some of the signs of someone with PE…
INSPECTION:
- Tachypnoea
PALPATION:
- Tachycardia
AUSCULTATION:
- Pleural rub
FURTHER TESTS:
- Low O2 sats
- Hypotension
- Pyrexia
Tends to be SUDDEN ONSET
List some of the signs of a Massive PE…
- Cyanosis
- Shock- hypotension, tachycardia
- Signs of right heart strain (cor pulmonale) : raised JVP, left parasternal heave, accentuated S2 heart sound
What is the first assessment to carry out in someone with suspected PE?
WELL’S SCORE
- PE unlikely ≤4, PE likely >4
Which imaging modality is first line for investigating someone with suspected PE? When would you offer this test?
Computed tomographic pulmoary angiography (CTPA)
- Helps visulaise thrombus in pulmonary artery- can see partial or complete intraluminal filling defect
- Offer if WELL’s greater than 4 or if WELL’s less than 4 but D-dimer is high
When might using CTPA be contra-indicated for use in investigating someone with PE. Which investigation can be performed instead? and how does it work?
- Pregnant women
- Renal failure
- Children and adolescents
V/Q Scan (Ventilation- Perfusion Scans)
- Identifies areas of ventilation and perfusion mismatch, which would indicate an area of infarcted lung
Other than Well’s Scores, CTPA and VQ scans what other investigations could be ordered to identify patient with PE
- Bloods- U&Es, ABG, Coagulation, FBC , D-dimer test
- ECG
- CXR
To exclude other causes of chest pain
- Doppler/ Duplex US to visualise DVT in lower limbs
- Echocardiagraphy- to see cor pulmonale
What might you see on an ECG of someone with PE?
- S1Q3T3 pattern – indicative of RV strain and therefore suggestive of PE.
- a prominent S wave in lead I
- a Q wave and inverted T wave in lead III
What might you see on a CXR of someone with PE? and why
Westermark sign is a focus of hypovolaemia distal to the pulmonary artery that has been occluded by the PE. Blood cannot reach this region causing ischaemia and eventual infarction. This increases the translucency of the region. It is highly specific for PE but only occurs in an estimated 10% of cases.
