Pulmonary Embolism (PE) | Acute Management | ABCDE

A pulmonary embolism (PE) is life-threatening and must be recognised and treated in a timely manner.

This guide gives an overview of the recognition and immediate management of PE using the ABCDE approach. You can check out our overview of the ABCDE approach here.

This guide has been created to assist students in preparing for emergency simulation sessions as part of their training. It is not intended to be relied upon for patient care.


Clinical features of a PE

A study in 2009 reported that in 1 in 4 patients with a PE, the first manifestation will be sudden-unexpected death. ¹ PE is an important cause of out-of-hospital and in-hospital arrest and as such is part of the 4 H’s and 4T’s of irreversible causes of cardiac arrest.

The diagnosis of a PE cannot be made on examination alone. In fact, clinical examination can be absolutely normal and unless you consider a PE as the cause of your patient’s chest pain or shortness of breath (SOB) then you can easily miss it.

A PE should always be on your list as a cause of chest pain.


Risk factors

Risk factors for developing a DVT or PE include:

  • Recent surgery
  • Recent fractures
  • Recent immobility
  • Personal or family history of a clotting disorder or PE/DVT
  • Obesity
  • Malignancy
  • Infection
  • Pregnancy
  • Certain medications such as the combined oral contraceptive pill or hormone replacement therapy

When someone develops a PE and they have one of these risk factors it is referred to as a ‘provoked PE’.

If there are no known underlying risk factors it is called a ‘unprovoked PE’.



Clinical features in order of frequency are:

  • Shortness of breath
  • Pleuritic chest pain:
    • The pain in PE is typically pleuritic (occurs during inspiration)
    • This is because with each breath, the pleura comes into contact with an ischaemic area of lung
  • Cough
  • Haemoptysis – from infarcted lung tissue
  • Dizziness or syncope



Clinical signs include:

  • Tachypnoea: A respiratory rate of more than 20 breaths per minute
  • Tachycardia: A heart rate of more than 100 beats per minute
  • Hypotension:
    • This is a very worrying sign and suggests right ventricular strain
    • A raised JVP may also be noted in the context of right ventricular strain
  • Evidence of deep vein thrombosis (DVT) such as a red, swollen calf
  • A pleural rub or findings in keeping with a pleural effusion
  • Cyanosis is a late sign and indicates a significant drop in blood oxygen levels


Tips before you begin

  • Treat all problems as you find them
  • Re-assess regularly and after every intervention to see if your management is effective
  • Make use of the team around you to delegate tasks where appropriate
  • All critically unwell patients should have continuous monitoring equipment attached for accurate observations including:
    • Blood pressure
    • 3-lead ECG
    • Oxygen saturations
    • Heart rate
    • Respiratory rate
  • Communicate how often you would like these observations to be relayed to you
  • Call for help early using an appropriate SBARR handover structure (check out the guide here)
  • You need to both request investigations and review results as they become available
  • You don’t have to memorise everything off by heart, ask for guidelines and algorithms that are relevant (i.e. PE treatment guidelines)
  • If you would like medications or fluids, these will need to be prescribed
  • Don’t forget to document everything you have found and done in the patient notes!


Initial steps

You are likely to be called to see this patient either:

  • On the ward or
  • As a new presentation to ED with chest pain and/or shortness of breath



Perform a quick general inspection of the patient to get a sense of how unwell they are:

  • If the patient is unconscious, check for a pulse and check that the patient is breathing.


If the patient is unconscious or unresponsive and not breathing start the basic life support (BLS) algorithm as per resuscitation guidelines. Call 2222 for help! (see our BLS guide here)

  • Perform AVPU and assess their consciousness level
  • How do they look?
  • What is their breathing like?
  • Are there any clues from around the bedside? (look for drug charts, medication, IV lines, monitoring equipment etc)



  • Introduce yourself to the patient
  • If the patient is able to answer questions, ask how they are feeling



Ensure you have everything that is available to you

  • Patient notes
  • Drug charts including diabetes charts
  • Observations charts
  • If they have been an inpatient, have they been receiving thromboprophylaxis?
  • Is the patient normally on warfarin/dabigatran/rivaroxaban/apixaban? (If so, are they compliant with their medications?)




Assess the patient’s ability to speak, listen to the patient’s breathing for added sounds and inspect the mouth.


If you think your patient has a compromised airway you need help! Put out a crash call immediately as you require urgent anaesthetic input to secure the airway. You can perform some simple airway manoeuvers in the meantime.

Maintaining the airway whilst awaiting senior support

1. Perform a head tilt, chin lift manoeuvre.

2. If noisy breathing persists, try a jaw thrust.

3.  If this is still not enough to open up the airway you can consider the use of an airway adjunct:

  • If your patient is still semi-conscious then consider using a nasopharyngeal (NP) airway.
  • If your patient is able to tolerate an oropharyngeal (OP, or Guedel) airway then you can use one of these. However, this indicates that your patient is seriously unwell as they no longer have a gag reflex.


Reassess after any intervention

If your patient starts to improve throughout your assessment, they may no longer be able to tolerate the OP airway and you should remove it as soon as possible to prevent gagging/aspiration.




Oxygen saturation: aim for 94-98%

Respiratory rate

  • Tachypnoea is the body’s response to hypoxia.
  • Impaired consciousness may lead to a reduced respiratory rate (bradypnoea).


Auscultate both lungs:

  • Reduced air entry bilaterally suggests significant airway compromise and the need for critical care input.
  • Crackles or crepitations on auscultation may represent a pleural effusion due to infarcted lung parenchyma.
  • Palpate and percuss to assess chest expansion and resonance/dullness.



Arterial blood gas

  • An arterial blood gas may be useful to quantify the degree of hypoxia if your patient has low oxygen saturations
  • ABG results in PE may show low PaO2 and normal/low PaCO2
  • A massive PE can lead to a metabolic acidosis


Chest x-ray

  • In most cases of PE, a chest x-ray will be completely normal. However, it is a useful tool for ruling out other lung pathology (e.g. pneumonia).
  • CXR findings associated with PE include pleural effusion and/or an area of atelectasis where a small area of lung tissue has collapsed.
  • A consolidation on the chest x-ray may represent an established area of infarcted lung.


Well’s score

  • At this stage, without any investigation results, you cannot be certain if you are dealing with a PE or not.
  • The definitive diagnosis of PE can only be made with a CT pulmonary angiogram (CTPA) or, less commonly, a VQ scan.
  • NICE guidance is to calculate clinical probability of DVT/PE using a 2-level Wells score.²
  • A Well’s score assigns various clinical features a specific number of points and you need to add up these points to determine the total Well’s score.
Clinical featurePoints
Clinical signs/symptoms of DVT3
PE is the most likely diagnosis3
Tachycardia >100bpm1.5
>3 days immobility or surgery in the last month1.5
Previous DVT/PE1.5
Clinical probability
PE likely>4 points
PE unlikely4 or less points




If the Wells score is greater than 4 (PE is likely), a CTPA is indicated:

  • If there is going to be a delay in getting a CTPA you should start anticoagulants in the meantime.
  • Refer to your local guidelines to see which anticoagulant is recommended (this is often low molecular weight heparin or a novel oral anticoagulant (NOAC).


If the Wells score is 4 or less and a PE is unlikely but still a differential to exclude, a D-dimer test can then be used to rule out a PE (e.g. if D-dimer is negative, the likelihood of a PE is very low).

  • As a result, those patients who are deemed low risk on the Wells score are spared the risks of a CTPA if the D-dimer result is negative.
  • If the D-dimer result is raised (positive) then a CTPA or VQ scan will be required to reach a definitive diagnosis of PE .


D-dimer can be raised for a number of different reasons other than the presence of PE or DVT, so a raised D-dimer is not diagnostic for PE or DVT (it is used only to help rule out the diagnosis). D-dimer can be raised due to infection, recent surgery and malignancy.

VQ scans are typically used for patients for which CTPA is contraindicated (e.g. renal impairment, contrast allergy, pregnancy).




  • Administer oxygen as soon as possible:
    • High-flow oxygen (15 litres) through a non-rebreathe mask
  • If the patient is conscious, sit them upright
  • Maintain oxygen saturations between 94-98%


Assisted ventilations

  • If your patient is unconscious and their respiratory rate is inadequate (too slow or irregular with big pauses), you can provide assisted ventilations through a bag-valve-mask (BVM):
    • Ventilate at a rate of 12-15 breaths per minute (roughly one every 4 seconds)


PE treatment

If you can get a CTPA or VQ scan done quickly then you may be able to wait for the definite diagnosis before implementing treatment. However, as there is usually at least a small delay we often commence therapeutic doses of an anticoagulant whilst awaiting investigation results.

  • Look at the guidelines available to you to see what anticoagulant agents are recommended at your institution.
  • NICE guidance advises prescription of  low-molecular weight heparin, fondaparinux or unfractionated heparin. ³
  • You should start an oral anticoagulant (NICE recommends warfarin) within 24 hours of diagnosis and continue it for at least 3 months.
  • Anticoagulant treatment may be continued for a longer period if the PE was unprovoked (no known underlying cause).

A massive PE may require urgent treatment with an intravenous thrombolytic agent. This is a consultant led decision and you should therefore seek urgent senior review if you suspect massive PE.

Signs of massive PE occur secondary to right ventricular strain:

  • Hypotension
  • Raised jugular venous pressure
  • Heart failure
  • Cardiac arrest


Reassess after any intervention.





  • Your patient will most likely be tachycardic however some patients have a normal heart rate despite PE


Blood pressure

  • Pain may lead to hypertension
  • Hypotension is a concerning sign and represents cardiac failure secondary to right heart strain (massive PE)



  • Your patient may appear clammy/pale/grey
  • Capillary refill time may be normal or sluggish due to hypovolaemia


Take blood samples

  • Try if possible to collect blood samples during cannulation
  • Troponin I or Troponin T: The cardiac enzymes are released from damaged cardiac cells and are a key part of diagnosing myocardial infarction. PE can cause a rise in troponin if there has been prolonged tachycardia and right ventricular strain.
  • Full Blood Count: For a haemoglobin and platelet measurement. You can also look for markers of infection.
  • CRP: For markers of infection/inflammation.
  • Urea and Electrolytes: To assess renal function (important if considering CTPA)
  • Liver Function Tests and Clotting
  • Serum Glucose


Record an ECG

The most common ECG finding in PE is sinus tachycardia.

PE can cause any of the following ECG changes:

  • T wave inversion
  • New onset atrial fibrillation
  • Right bundle branch block
  • Right axis deviation
  • S1Q3T3 (this is a specific pattern that is seen rarely in PE):
    • S waves in lead I
    • Q waves in lead III
    • T wave inversion in lead III


Secure intravenous access

  • The gold standard is to insert 2 large bore cannulas for acutely unwell patients.


Administer IV fluids

  • Titrate your fluids to the patient’s level of haemodynamic instability
  • Typically NaCl 0.9% or Hartmann’s solution is used for fluid resuscitation


Reassess after any intervention.




Blood glucose level

  • Check the patient’s blood glucose level, particularly if they are a known diabetic


Assess pupils

  • What size are they?
  • Are they equal?
  • Are they reactive to light?


Assess level of consciousness- AVPU/GCS

  • The above Airway, Breathing and Circulation problems can all alter the patient’s neurological status because of decreased cerebral perfusion, causing the patient to be confused or drowsy.
  • A formal record of your patient’s consciousness level will be really useful for tracking progress and changes throughout treatment.


Reassess after any intervention.





  • We routinely expose all unwell patients to make sure that we aren’t missing anything.



  • Patients with PE can develop a fever as part of the catecholamine response.

Urine output

  • Urine output will likely need monitoring if administering fluids, to ensure an accurate fluid balance is recorded.


Reassess after any intervention.


Reassess ABCDE

It is essential to continually reassess ABCDE and treat issues as you encounter them. This allows continual reassessment of the response to treatment and early recognition of deterioration.


Next steps

Well done! You have successfully implemented the immediate treatment for your patient. Your patient has been started on appropriate treatment and their observations are improving. There are just a few more things to do…


Take a history

If possible, it is important to revisit history taking to clarify risk factors for PE and other relevant medical information. If the patient is confused you might be able to get a collateral history from staff or family members as appropriate. Check out the history taking guides here.



  • Patient notes
  • Observation charts
  • Fluid charts
  • Investigation findings
  • Additionally, make sure to check the medications you have just prescribed and what the patient normally takes. This helps reduce prescribing errors and allows you to consider any possible drug interactions.



It is really important that you document your initial ABCDE findings, any interventions you made and the response the patient had to those interventions. Make sure to document salient points from the history.



You need to discuss the patient with the medical team. If your patient requires a higher level of care (HDU, ICU or CCU) then you need to speak to the appropriate teams directly.

As a junior doctor it would be appropriate to give an SBARR handover outlining your assessment, actions, and to discuss the following:

  • Does the patient need a referral to HDU/ICU?
  • Does the patient need further treatment?
  • Are there any further assessments, investigations or interventions required?
    • For example, an echocardiogram may be indicated to look for evidence of heart strain.
  • Should they be referred for a review by a specialist doctor?
  • Should any changes be made to the management of their underlying conditions?



1. Lucena, J., Rico, A., Vazquez, R., Marin, R., Martinez, C., Salguero, M. and Miguel, L. (2009). Pulmonary embolism and sudden-unexpected death: prospective study on 2477 forensic





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