Pulmonary embolism Flashcards
What are 6 clinical features of pulmonary embolism?
- Chest pain - typically pleuritic
- Dyspnoea
- Haemoptysis
- Tachycardia
- Tachypnoea
- Respiratory examination
- classicaly chest will be clear
- in real-world practice findings are often found
What are 4 frequently clinical findings in pulmonary embolism and what are their respective frequencies?
- Tachynpnoea (resp rate >16): 96%
- Crackles: 58%
- Tachycardia (HR>100): 44%
- Fever (temp> 37.8): 43%
What proportion of patients with PE present with the triad of symptoms: dyspnoea, pleuritic chest pain and haemoptysis?
few - 10%
What do the cardiorespiratory signs/ symptoms of PE depend on?
location and size
What 3 basic investigations should be performed initially in patients with symptoms or signs suggestive of PE?
history, examination, CXR to exclude other pathology
What is the tool introduced for the assessment of likelihood of venous thromboembolism by NICE in 2020?
PERC rule: pulmonary embolism rule-out criteria
How does the PERC rule work when assessing likelihood of PE?
all criteria must be absent to have negative PERC result, i.e. you can rule out PE (probably <2%)
When should the PERC rule be used when assessing the likelihood of PE?
if there is a low pre-test probability of PE, but want more reassurance that it isn’t the diagnosis
(low = <15% probability)
If your suspicion of PE is greater than ‘low’ that would make you consider using the PERC tool, which tool should be used instead?
2-level PE Wells score
What does the 2-level PE Wells score consist of? 6 aspects
How is the result of the 2-level PE Wells score interpreted?
clinical probability simplified scores:
- >4 points: PE likely
- 4 or less: PE unlikely
What is the next step in investigation if PE is considered likely from the Wells score?
arrange immediate CTPA (computed tomography pulmonary angiogram)
if delay in getting CTPA, interim therapeutic anticoagulation should be given until scan is performed
What anticoagulation should be given in the interim if waiting for CTPA to be performed and there is a delay?
DOAC: apixaban or rivaroxaban
What is the next step in management/investigations based on the result of CTPA for a Wells score >4?
- positive: PE diagnosed
- negative: consider proximal leg vein ultrasound scan if DVT suspected
What is the next step in investigation for PE if Wells score is 4 points or less?
D-dimer test
Based on the results of the D-dimer test following a Wells score of 4 points or less what are the next steps in management?
- d-dimer positive: arrange immediate CTPA, if delay consider interim therapeutic anticoagulation
- d-dimer negative: PE unlikely, stop anticoagulation and consider alternative diagnosis
What are 4 advantages of CTPA over V/Q scans to diagnose PE?
- CTPA faster
- CTPA easier to perform out of hours
- Reduced need for further imaging following CTPA
- Possibility of CTPA providing alternative diagnosis if PE excluded
What are 3 situations in which a V/Q scan may be performed initially rather than CTPA?
- If appropriate facilities exist
- If CXR normal
- If no significant symptomatic concurrent cardiopulmonary disease
When is V/Q scanning the investigation of choice for suspected PE (over CTPA)?
if there is renal impairment - no requirement of contrast
When should age-adjusted d-dimer levels be considered?
patients >50 years
What are the classic ECG changes in PE?
- S1Q3T3
- prominent S waves in lead I
- large Q wave in lead III
- inverted T wave in lead III
In addition to S1Q3T3 what are 3 further ECG changes which are seen in PE?
- Right bundle branch block
- Right axis deviation
- Sinus tachycardia - commonest finding
What type of PE is shown in the image?
saddle embolus
