85% of all cases of dyspnoea are accounted for by asthma, cardiac failure, COPD, pneumonia, interstitial lung disease and psychogenic disorder, but don’t forget pulmonary embolism and pneumothorax as other differentials.


'Breathlessness' or 'shortness of breath' is a common presenting complaint to the Emergency Department. There are a large number of causes for this presentation and several medical terms used to describe it (see below) but no concise definition. It is described as a subjective feeling of difficult or uncomfortable breathing or a feeling of 'not getting enough air'. There is a broad range of pathophysiology which can cause dyspnoea; one of the key initial steps for the Emergency Physician is to determine the primary physiological system involved.

85% of all cases of dyspnoea are accounted for by asthma, cardiac failure, COPD, pneumonia, interstitial lung disease and psychogenic disorder. Don't forget pneumothorax and pulmonary embolism. Any patient with significant dyspnoea will require a rapid assessment of their vital signs followed by appropriate resuscitation (airway support, supplemental oxygen, ventilatory support, etc.).

Patients who do not require immediate resuscitation will have their management guided by a thorough clinical assessment commencing with a focussed history and examination. Certain examination findings upon respiratory system examination are diagnostic in the context of presentation with dyspnoea. Pulse oximetry provides a simple, accurate, non-invasive and continuous means of monitoring arterial oxygen saturation. A number of factors can affect the accuracy of pulse oximetry and it is important to be aware of its limitations. ABG analysis is the investigation of choice for assessment of a patient’s respiratory and acid-base status.

Remember: A high RR can also be caused by non-respiratory pathology, for example compensation for a metabolic acidosis.

CXR is the most commonly performed radiological examination in the Emergency Department. After taking a history and performing a clinical examination, CXR is essential for most causes of dyspnoea both in terms of making a diagnosis and influencing treatment. 

Shortness of breath can be a frightening presenting complaint for patients and Emergency Physicians. Think about the top five life threatening causes and actively rule them out.

Top 5 differential diagnoses:
  1. Pneumonia
  2. Asthma/COPD
  3. Pulmonary Embolism
  4. Acute left ventricular failure
  5. Pneumothorax

Learning Outcomes from Completing the Tasks

  • Differentiate between the different causes of SOB

  • Select the appropriate investigations to help differentiate the causes of SOB

  • Formulate a management plan for the different causes of SOB including resuscitative measures in: COPD, Asthma, LVF, Pneumonia, Pneumonia, Pneumothorax and Pulmonary embolism

  • Interpret investigations in SOB including ABGs.

  • Apply local ED or national protocols: Asthma, Ambulatory PE pathway, Acute hypercarbic respiratory failure in the ED and Pneumothorax


Complete the following before the face-to-face session:

TASK 1: Shortness of Breath

Duration: 21 mins

This really good video has been produced by the team at Southampton for their junior doctors.

TASK 2: Breathlessness

Duration: 45 mins

This learning module encompasses all the main differentials into  systematic approach to the patient with SOB in the ED. It is from the RCEMLearning website, which replaced enlighten. All modules are linked to the RCEM curriculum and bet of all they are free! (Membership is required if you want certificates though) If you haven't been to the website before it is worth spending a few minutes having a look at the other content.

TASK 3: Asthma

Duration: 8 mins

Another video from the team at southampton, this time on Asthma. Once you have completed this task it may also be worth refreshing yourself with the BTS/ SIGN guidelines found in the additional resources below.

TASK 4: Arterial Blood Gas Analysis

Duration: 60 mins

Arterial blood gas interpretation can be challenging, but can also be crucial when formulating a management plan, once again the RCEMLearning Website can provide assistance. This eLearning module provides the relevant information to apply on the shopfloor.

TASK 5A: Management of Spontaneous Pneumothorax

Duration: 15 mins

Review this flowchart from the British Thoracic Society (BTS) on the management of spontaneous Pneumothorax

TASK 5B: Chest Drain Insertion

Duration: 60 mins

Those working at University Hospitals of Leicester can access the following eLearning Module on Chest Drain Insertion via eUHL. There is also a youtube video on the technique available to all.

eUHL Chest Drain course

eUHL Chest Drain course

#EM3 Content



Mini Teaches:

Case Discussion

We have written a series of interactive cases (wikis) with short answer questions to be answered by trainees prior to the face to face teaching sessions. Currently this is only available to East Midlands Trainees.

Answer one or two questions before attending the face-to-face teaching session. Add comments to answers already given if you think it's appropriate. We will also provide tutor comments. If you find good resources that answer a question why not include links in your comment.

Part of the face-to-face teaching will be spent discussing the case(s) below:

A 34 year old woman presents to Emergency Department with acute shortness of breath. This has begun suddenly some 8 hours ago.
A 67 year old gentleman is brought in by ambulance to the Emergency Department Resus with a productive cough of green sputum and increasing SOB over a few days.

Additional Resources

Here are some extra resources to review if you want more information:

Breakfast at Glenfield:


PE Lecture:

RCEM Learning:

Course Feedback

Once you have worked through the exercises, discussed the example cases and attended the face-to-face teaching, please complete the following form:

Updated: 5th January 2017