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Peak flow measurement

Activity: 
Visitors to take a peak flow test to measure how fast they can blow air out of their lungs.

Aim: 
To introduce the concept that we can measure lung function and that this can deteriorate for people with allergic asthma.

How to make:

  • You will need at least two peak flow meters - preferably one 'adult' size and one 'child' size - as well as disposable cardboard mouthpieces.
  • Draw a graph of height vs. peak expiratory flow (PEF) on some A1 or A2 flipchart paper and attach to an easel or something similar.
  • Ensure you have a tape measure handy or a metre stick to measure people's heights.

What to do:

Ask visitors to take a peak flow measurement and plot it against their height. To take a peak flow reading, check the monitor is at zero and the visitor is sitting/standing in a comfortable position. Place a disposable mouthpiece over the peak flow meter mouthpiece and, holding the meter horizontally, they should take a deep breath and close their mouth firmly around the mouthpiece. They should then blow out as hard as they can (like blowing out candles on a birthday cake). Next, ask them their height or, if they don't know it, measure them with the tape measure. Ask them to plot their height against their peak flow reading - for small children you can do this for them if you need to. Over time you should see a correlation between PEF and height (i.e. taller people generally have bigger lung capacity as detailed by their PEF). Use this to explain what other factors can impact on PEF - such as allergic asthma.