using a peak flow PEFR

Question 1

equipment

Answer 1

Equipment: - Hand held Peak Flow Meter

Disposable cardboard mouthpiece

Question 2

intro and setup

Answer 2

1. Collect together equipment and test.
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2. Check patient’s details to ensure you are dealing with the correct person.
3. Introduce self and explain procedure.
4. Ensure the device reads zero or is at base level of the recording meter.
5. Ideally patient should be standing for this procedure. Help patient to stand if needed.
6. Attach mouthpiece to flow meter

Question 3

procedure to end

Answer 3

7. Ask patient to place device into mouth with lips enclosed around end of mouthpiece, hand holding
   the meter underneath so they don’t restrict the movement of the pointer.
8. Patient should inhale deeply and then exhale quickly and forcibly. (Remember - it is not the amount
   of breath that is being measured but the speed in which it is exhaled). Say, “I want you to take a deep
   breath and then blow out as hard and as fast as you can, as though you’re trying to get all the air out
   of your lungs in one go”.
9. This should be repeated 3 times allowing the patient to recover between each episode.
10. Record the highest reading of the 3.
11. If the patient is on a bronchodilator e.g. salbutamol, you will need to perform the peak flow measurement after its administration. This would then give you pre and post peak flow measurements, which are documented on a peak flow chart

Question 4

What factors affect the peak flow reading?

Answer 4

Gender, build (height), age and disease status.

Question 5

What pattern might you see in peak flow in someone with asthma?

Answer 5

There is diurnal variability in the PEFR of someone with asthma – it is lower in the morning, highest in
the middle of the day and then really low in the evening.

Question 6

What would you expect a normal PEFR to be?

Answer 6

This greatly depends on the factors above, but broadly speaking 380-500L/min in women and 520-
660L/min for men.

Question 7

How could you use peak flow to distinguish between someone with asthma and someone with
COPD?

Answer 7

You could give a bronchodilator – in COPD there will be little or no reversibility, but in asthma there
will be a marked improvement in PEFR.