Peak Flow Meter: How to Monitor Asthma
What is the purpose of the peak flow meter?
The peak flow meter measures how fast air can be exhaled in one breath. Measuring the
peak flow regularly can help predict early signs of an acute asthma episode and how well
medications are working.
When should the peak flow meter be used?
Measure the peak flow before and after each bronchodilator treatment and when an acute
asthma episode occurs. Record the measurements in a daily log to help your doctor know how
well medications are working.
How is the peak flow meter used?
Each brand of peak flow meter works a little differently. Carefully read the
instructions included with your meter.
General instructions are:
- Place the mouthpiece on the peak flow meter.
- Place the indicator at the bottom of the scale close to the mouthpiece.
- Hold the peak flow meter upright, being careful that fingers do not block the
- Inhale as deeply as possible. Place the mouth firmly around the mouthpiece beyond
the teeth, making a tight seal with the lips.
- Blow out as hard and fast as possible.
- The marker will move and indicate the peak flow measurement. Note the measurement,
return the marker to the base of the scale, and repeat steps 3 through 5.
- Write down the date, time, and higher of the two measurements in the log.
When and how should the peak flow meter be cleaned?
Once a week clean the mouthpiece of the meter with warm water and dry it thoroughly.