How do I use my Peak Flow?

In this new series, we will be highlighting a range of respiratory-related devices and explaining best practice on how to use these. This week, we demonstrate how to use a peak flow meter, and why it is important to use one.

What is a peak flow meter?

A peak flow meter is a small device that helps you check how well your asthma is controlled. The levels on the peak flow measure how much air you can breathe out in one fast breath, which then indicates how swell your lungs are functioning.

Why do we use peak flow readings?

Peak flow meters are firstly used to measure your ‘best peak flow’, which is your benchmark reading of how strong your lungs are when you are healthy and without symptoms. This result is also used to formulate your Asthma Action Plan. Once this benchmark reading has been recorded, and you find that you are unable to meet your best peak flow reading, this may indicate that your asthma symptoms are worsening and that you need to step-up your treatment, which will be documented Asthma Action Plan.

How do I find my best peak flow?

To find your personal best peak flow reading, take your peak flow at the same time each day for one week. Your asthma should be under control during this time.

Write down the number you get for each peak flow measurement. The highest peak flow reading you have during this week is your ‘personal best’.

Once you have you personal best reading, ask your healthcare professional to help you fill out an Asthma Action Plan. This plan will inform you when to use your prescribed medicines if your peak flow drops to a certain level, and when you need to call for help. However, it is important to remember that your personal best can change over time. Ask your health professional when you should re-assess for a new personal best.

How do I take a peak flow reading?

1- Move the marker of the peak flow to the bottom of the numbered scale.

2- Stand up straight and take a deep breath. Fill your lungs all the way.

3- Hold your breath while you place the mouthpiece in your mouth, between your teeth. Close your lips around it.

DO NOT put your tongue against or inside the hole.

4- Blow out as hard and fast as you can in a single blow. Your first burst of air is the most important. So blowing for a longer time will not affect your result.

5- Write down the number you get. But, if you coughed or did not perform the steps correctly, do not write down the number. Instead, repeat the steps over again.

6- Move the marker back to the bottom and repeat all these steps two more times. The highest of the three numbers is your peak flow number.

Did you know that you can have your Asthma Action Plan on you at all times with the My Asthma App?

If you have a peak flow symptom diary, record this number, and repeat over the week. Then add these figures up and divide by seven to give you your average peak flow. If you are feeling well over this time and are no experiencing asthma symptoms, this number forms your ‘average’ peak flow for that week.

Give this figure to your healthcare professional, and together this can be used to create an Asthma Action Plan, which details what steps to take when your peak flow falls below these levels.

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