How do I do peak flows?

A peak flow meter is the most important tool you can use to monitor your child's asthma. A peak flow meter is a little tube with a gauge on it that measures lung function. A child blows as hard and fast as he can into the tube. The resulting number on the gauge is your child's peak flow number.

 To get the best number, have your child:

  1. Stand up straight and take a few slow, deep breaths.
  2. Reset the gauge on the peak flow meter to 0.
  3. Take a big deep breath and close the lips around the peak flow meter.
  4. Blow out as hard and as fast as possible through the peak flow meter.
  5. Check the result on the gauge.
  6. Repeat steps 2 through 5 twice.
  7. Record the highest number of the three tries on your peak flow log sheet.

Common problems children have with peak flows:

  • Not getting a good lip seal around the tube. Air can blow out the corners of the mouth. This falsely reduces the peak flow number.
  • Not blowing out as fast as possible. Tell your small child to blow out "like a dragon breathing fire, not like blowing a kiss."
  • Not remembering to write down the result. Be sure to write down your daily peak flows in your log sheet. It's much easier than trying to remember a month's worth of numbers in your head!