Peak expiratory flow rate (PEFR) measurement often appears in OSCEs and involves a combination of both information giving (explaining the procedure) and the practical clinical skill of performing PEFR measurement. The communication skills aspect of this station is where most of the marks lie, so ensure you provide a clear explanation of the procedure to the patient, checking understanding and summarising as you go along.

Check out the peak expiratory flow rate (PEFR) mark scheme here.


Wash hands

Introduce yourself – state your name and role

Confirm patient details – name and DOB


Explain the purpose of the procedure:

“I’d like to assess your breathing”

“This involves measuring how well the air can flow out of the lungs”

“It’s an important test, as it gives an indication of how well your asthma is controlled”


Gain consent – “Do you understand everything I’ve said?” “Are you happy to go ahead with this?”

Measuring PEFR

Ensure you clearly explain and demonstrate each step of the procedure below to the patient.

1. Ensure the PEFR meter is set to zero

2. Sit up straight or stand

3. Take a deep breath (as deep as you can possibly manage)

4. Place your mouth around the mouthpiece of the PEFR meter, ensuring a tight seal with your lips

5. Exhale as forcefully as you possibly can manage

6. Note the PEFR reading

7. Repeat this process a further 2 times

8. The highest reading of the 3 should be taken as the overall result

  • Insert peak flow mouthpiece
    Insert mouthpiece

To complete the procedure…

Observe patient performing PEFR measurement to ensure appropriate technique.

Ask if the patient has any questions regarding PEFR technique.

Thank patient

Wash hands


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