This is a practice OSCE station for UKMLA content.
Contents
- How to use
- Candidate brief
- Examiner Questions
- 1. What are your key differential diagnoses?
- 2. Please interpret the following ABG.
- 3. Please calculate this patient’s Wells score.
- 4. What would be the initial steps of management based on the Wells score?
- 5. How long should treatment be continued for?
- 6. What are the classical ECG findings associated with a pulmonary embolism?
How to use
Candidate:
- Read the brief below (1 minute).
- Take a history (6 minute).
- Answer viva questions (3 minute).
Patient/Examiner:
- Familiarise yourself with the history & examination findings
- After completing the history, viva the candidate
Candidate brief
Alice is a 35 year old woman presenting to A&E with chest pain. Please take a history, carry out a focussed examination and answer the questions that follow.
Presenting Complaint
‘SOCRATES‘ is useful for assessing pain-related presenting complaints.
- Site – left sided
- Onset – started the previous day, patient can’t remember if this is sudden or gradual.
- Character – sharp
- Radiation – along the left side of the chest
- Associated symptoms – cough
- Further details should only be provided if the candidate enquires further.
- The cough started at around the same time as the chest pain. Initially was non-productive, but today has noticed some blood.
- Timing – present since the previous day
- Exacerbating/ Relieving factors – worse on inspiration, nothing has made the pain better
- Severity – 7/10
Systems Review
- Red flags: no fever, no weight loss, no night sweats
- Cardiac: no palpitations, no syncope, right leg is swollen and red
- Respiratory: some shortness of breath which has been progressing since arriving at A&E
Previous Medical History
- Coeliac disease
Medications
- Combined oral contraceptive pill. Started 15 years ago.
Allergies
- None
Social History
- Works as a primary school teacher
- Came back by plane from a holiday in Australia last week
- Smokes 5 cigarettes a day for the last 10 years
Family History
- Grandmother had a stroke at the age of 67
ICE
Expectations – nothing specific. Candidate should notice the anxiety and address this.
Ideas – doesn’t know what’s going on, but coughing up blood isn’t a good sign?
Concerns – since coughing up blood is concerned this could be something serious and life-threatening.
Vitals
- Temperature – 36.5°C
- Heart Rate – 57
- SpO2 – 92%
- BP – 130/87
- Respiratory Rate – 28
Inspection
- General – comfortable at rest
- Hands – normal Capillary Refill Time, no clubbing, no CO2 retention flap
- Face – no conjunctival pallor, no cyanosis
- JVP – normal
- Legs – Right leg is red and more swollen than the left.
- Chest – No scars
Palpation
- Trachea central
- Chest expansion equal
Percussion
- Normal percussion
Auscultation
- Normal breath sounds
- No evidence of added sounds such as wheeze or crackles
Examiner Questions
1. What are your key differential diagnoses?
- Pulmonary embolism: The patient is describing a typical history of chest pain of a pleuritic nature, haemoptysis and shortness of breath. A history of COCP use and long-haul air travel combined with a swollen leg should raise suspicion of a DVT precipitant to the episode (1,2).
- Pneumonia: could be an atypical history of pneumonia, however in the absence of fever or a cough productive of sputum this is less likely than a pulmonary embolism (3).
- Musculoskeletal chest pain: should only be considered when other causes have been ruled out.
2. Please interpret the following ABG.
| ABG Results |
| pH = 7.48 |
| PaO2 = 7.3kPa |
| PaCO2 = 4.3kPa |
| HCO3– = 23 mEq/L |
| Base Excess = 0 mmol/L |
- This ABG shows type 1 respiratory failure (hypoxia and normocapnia) in addition to respiratory alkalosis. This is in keeping with a pulmonary embolism causing hypoxia and hyperventilation (4).
3. Please calculate this patient’s Wells score.
- Full Wells score can be found in NICE thromboembolic guidelines (5,6)
- Wells score = 7 (DVT signs and symptoms + Alternative diagnosis less likely + Haemoptysis).
4. What would be the initial steps of management based on the Wells score?
- As the patient scores more than 4 points, a CTPA should be ordered and D-dimer should not be used initially (5, 7).
- NICE guidelines recommend first line treatment should be a DOAC (unless contra-indicated) (5).
5. How long should treatment be continued for?
- If a DVT or PE is provoked (e.g. following a period of immobilisation after surgery which has since resolved) then treatment should be continued for 3 months.
- NICE guidelines suggest treatment should continue for longer if the PE is unprovoked (5).
6. What are the classical ECG findings associated with a pulmonary embolism?
S1Q3T3 – this refers to the presence of S waves in ECG lead 1, combined with lead 3 Q waves and T wave inversion (1,8).
Sinus tachycardia
References
1. National Institute for Health and Care Excellence. Pulmonary embolism [Internet]. NICE; 2022 [revised 2022 March; cited 2023 March 23]. (CKS). Available from: https://cks.nice.org.uk/topics/pulmonary-embolism/
2. Weegenaar C. Pulmonary Embolism (PE) Acute Management ABCDE [Internet]. Geeky Medics; 2022 [updated 2022 Jul 6; cited 2023 March 23]. Available from: https://geekymedics.com/pulmonary-embolism-pe-acute-management-abcde-approach/
3. National Institute for Health and Care Excellence. Chest pain [Internet]. NICE; 2022 [revised 2022 August; cited 2023 March 23]. (CKS). Available from: https://cks.nice.org.uk/topics/chest-pain/
4. Zaininger P. ABG interpretation [Internet]. Geeky medics; 2022 [updated 2022 Oct 24; cited 2023 March 23]. Available from: https://geekymedics.com/abg-interpretation/
5. National Institute for Health and Care Excellence. Venous thromboembolic diseases: diagnosis, management and thrombophilia testing [Internet]. NICE; 2020 [published 2020 March 26; cited 2023 March 23]. (clinical guideline [No.NG158]). Available from: https://www.nice.org.uk/guidance/ng158
6. Wells PS, Anderson DR, Rodger M, Ginsberg JS, Kearon C, Gent M, et al. Derivation of a simple clinical model to categorize patients probability of pulmonary embolism: increasing the models utility with the SimpliRED D-dimer. Thromb Haemost 2000 Mar;83(3):416-420.
7. Freund Y, Cohen-Aubert F. Bloom B. Acute Pulmonary Embolism: A Review. JAMA. 2022 Oct 4;328(13):1336-45.
8. Burns E. and Buttner R. ECG changes in Pulmonary Embolism [Internet]. Life in the Fast Lane; 2021 [updated 2021 Nov 30; cited 2023 March 23]. Available from: https://litfl.com/ecg-changes-in-pulmonary-embolism/
Author – Ansaam El-Sherif
Editor – James Mackintosh
Last updated 04/02/24
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