World Thrombosis Day: would you recognise a pulmonary embolism?

Sixty-thousand people are estimated to die of a pulmonary embolism (PE) every year in the UK alone.

Add in five other European countries* and that number tops 300,000 – and 59% of those deaths were following undiagnosed venous thromboembolism.

These figures show how important it is for us to provide an early and accurate diagnosis; a PE occurs when a thrombus, or clot, that has formed in a large vein (frequently the lower leg) becomes dislodged and is carried through the venous system before entering into the pulmonary circulation. Small PEs may go undetected as they filter into the pulmonary bed and the patient may even be asymptomatic, but, if the embolism is large it can block pulmonary blood vessels - causing sudden death.

As the ‘third most common cardiovascular disease’ (Cameron et al, 2015), data suggests that if left untreated PE has high mortality. Potential signs and symptoms of PE are:

  • dyspnoea
  • pleuritic chest pain
  • raised respiratory and heart rate
  • decreased oxygen saturation
  • haemoptysis
  • pallor
  • sweating.

As clinicians we should employ a multi-modal approach to our patient assessment, taking into account the patient’s history (including relevant risk factors), their physical appearance and presenting signs and symptoms.

JRCALC also recommends the use of the Wells criteria. This is a score based on the clinical presentation of a patient to predict the likelihood that they are suffering with a PE. The patient is scored as follows: 



Clinical signs and symptoms of DVT (leg swelling and pain   with palpation of the deep veins)


PE is the most likely diagnosis


Heart rate >100bpm


Immobilisation or surgery in the previous four weeks


Previous DVT/PE




Active malignancy


Clinical probability of PE



High >6 points

Moderate 2-6 points

Low <2 points


The Wells criteria is, as with all scoring systems, fallible and therefore shouldn’t form the basis of your diagnosis, but it should add to your overall impression of the patient.

Remember, even if your patient scores low on the Wells criteria it isn’t enough to rule out a PE. Take into account deteriorating physiology, your patient’s appearance and their history in conjunction with this scoring system.

If you suspect a patient could be suffering with a PE, please record a Wells score and note ‘?PE’ on their patient documentation, if you don’t already do so. This should include all patients suffering with unexplained chest pain or breathing difficulties i.e. those that can’t easily be attributed to any other cause. 

For more information on PE assessment and management, please refer to your A4 JRCALC guidelines, pages 170-173.

Download a pocket-card of the Wells criteria to carry with you.

Download a copy of our ‘Think PE’ awareness posters.

If you’d like a printed version of these but don’t have so already, please talk to your admin team who should have hard copies.

Want to read more? Visit the NICE website for more guidance and information.

* The six European countries included in this figure are: UK, France, Germany, Italy, Spain and Sweden. In a study by Cohen et al (2007) figures showed that there were 370,012 PE related deaths, and 59% (217,394) of these deaths were following undiagnosed VTE.

Published 13th October, 2015

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