Asthma Attack

How to Use a Peak Flow Meter

How to Use a Peak Flow Meter

Every adult with asthma should have a peak flow meter. A peak flow meter measures how well air moves out of your lungs. The number that is obtained is called the peak expiratory flow rate (PEFR). The "personal best" value is the highest PEFR number that a person obtains when they are feeling well.

Here is how to use a peak flow meter:

  • STEP 1 - Move the indicator to the bottom of the numbered scale. Stand up.
  • STEP 2 - Take a deep breath, filling your lungs completely.
  • STEP 3 - Place the mouthpiece in your mouth and close your lips around it. Do not put your tongue inside the hole.
  • STEP 4 - Blow out as hard and fast as you can.
  • STEP 5 - Repeat the process two more times.
  • STEP 6 - Write down the highest of the three numbers.

Using a Peak Flow Meter to Determine the Severity of an Asthma Attack:

  • GREEN Zone - MILD Attack: PEFR 80-100% of personal best
  • YELLOW Zone - MODERATE Attack: PEFR 50-80%
  • RED Zone - SEVERE Attack: PEFR less than 50%

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