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    Asthma and the Peak Flow Meter

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    How Do I Use the Peak Flow Meter for Asthma?

    A peak flow meter is simple to use for tracking your asthma. Here's what you do:

    1. Stand up or sit up straight.
    2. Make sure the indicator is at the bottom of the meter (zero).
    3. Take a deep breath in, filling the lungs completely.
    4. Place the mouthpiece in your mouth; lightly bite with your teeth and close your lips on it. Be sure your tongue is away from the mouthpiece.
    5. Blast the air out as hard and as fast as possible in a single blow.
    6. Remove the meter from your mouth.
    7. Record the number that appears on the meter and then repeat steps one through seven two more times.
    8. Record the highest of the three readings in an asthma diary. This reading is your peak expiratory flow (PEF).

    To ensure the results of your peak flow meter are comparable, be sure to use your meter the same way each time you take a reading.

    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 night. Ask your doctor how often you should check your peak flow.

    How Do I Determine My "Personal Best" Peak Flow Number?

    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 asthma is under good control. Good control means you feel good and do not have any asthma symptoms.

    Your personal best PEF is important because it is the number to which all of your other peak flow readings will be compared. Your asthma action plan, developed along with your asthma doctor, is based on this number.

    To find your personal best peak flow number, take peak flow readings:

    • Twice a day for two to three weeks when asthma is in good control
    • At the same time in the morning and in the early evening
    • As instructed by your doctor or asthma care provider

    You should always use the same meter.

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