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    What is a peak flow meter?

    A peak flow meter is an inexpensive, portable, handheld device for people with obstructive lung conditions that is used to measure how well air moves out of your lungs. Measuring your peak flow using this meter is an important part of managing your symptoms and preventing an attack and should form part of your personal action plan2.
    Why should I measure my breath strength?
    Peak flow is a measure of how fast you can blow air out of your lungs when you exhale forcefully after inhaling fully. This measure is called a "peak expiratory flow," or "PEF." Keeping track of your PEF, is one way you can know if your condition is in control or worsening1. Then, in conjunction with your prescribed treatment plan, you can take appropriate action to bring your condition back under control.
    Monitoring your condition
    If your condition isn’t affecting you, you will have airways that are open, so you’re able to blow air out of your lungs quickly, which will give you a high peak flow reading. However, if your condition is not controlled, the airways will narrow and you will not be able to blow air out so fast, which will give you a lower peak flow reading.
    How is it measured2?
    Peak flow is measured using a small handheld device called a peak flow meter. The scale is in units of liters per minute (lpm). When you blow into the mouthpiece the small marker will move depending on how fast you are blowing. Where the marker ends up, is your peak flow reading. The highest reading from three attempts should be recorded as your personal best peak flow reading.

    Your healthcare professional will set the colour zone indicators based on your or your child’s personal best peak expiratory flow rate (the best peak flow measurement achievable when your condition is under control). The peak flow measurement will fall into one of three zones, as shown below.

    How is my personal best peak flow number determined?3


    The "personal best" peak expiratory flow (PEF) is the highest peak flow number you or your child can achieve over a two to three week period when your condition is under good control. Good control means you feel good and do not have any symptoms from your condition.
     

    Your personal best PEF is important because it is the number to which all of your other peak flow readings will be compared. You may have worked with your healthcare professional to develoop an action plan that is based on this number.
     

    You should always use the same peak flow meter and write your readings in your peak flow chart. Then, continue to take peak flow readings each morning. Daily readings will help you to recognize early drops in airflow and changes with the control of your condition.

    To find your personal best peak flow number, take peak flow readings:
    Twice a day for two to three weeks when your condition is in good control
    At the same time in the morning and in the early evening
    As instructed by your healthcare professional

    How often should I check my peak flow?


    Peak flow values are best if they are checked at the same time each day, preferably once in the morning and again at night3. Ask your healthcare professional how often you should check your peak flow.

    How to read a Philips PersonalBest peak flow meter?

    Three-zone traffic light system

    Green zone

    If the reading is above the green mark then your regular medication plan for use of controller medication should be followed.

    Yellow zone

    If the reading is between the yellow markers, your condition might be worsening. Follow your action plan for instructions on how to use your reliever medication to get back into a green zone.

    Red zone

    If the reading is below the red mark, then you should seek medical advice immediately.

    Using and caring for a Philips PersonalBest peak flow meter

    1. Remove the top cover
    2. Fold the hinged bottom cover down and click the halves together so that they form a handle
    3. Slide the red indicator to the bottom of the scale
    4. Stand up and breathe in as deeply as you can. Place your mouth around the mouthpiece to form a tight seal. Blow as hard and as fast as you can
    5. The number where the indicator stops is your peak flow measurement. Repeat from step 3 and take 3 measurements
    6. Record the highest measurement in your daily record chart, noting the time and the date

    How to use a peak flow meter

    DISCLAIMER: 
    Information on this website is informational only and should not replace the advice of a physician.
    ALWAYS FOLLOW THE DIRECTIONS FOR USE.

    References:
    [1] aaaai.org. Conditions-and-treatments/library/at-a-glance/peak-flow-meter. Accessed October 2017. 

    [2] Asthma.org.uk. All_about_asthma/controlling_your_asthma/resources_to_help_you/peak_flow_diary. Accessed Oct 2017. 

    [3] Webmd.com. Asthma/guide/peak-flow-meter. Accessed October 2017.