Illustration copyright 2000 Nucleus
Communications, Inc. All rights reserved.
A peak flow (PEF) meter is a pocket-sized machine that measures peak
expiratory flow (PEF). A person measures PEF by taking a deep breath and then
breathing into a tube on the meter as hard and as fast as possible. PEF results
depend on how hard you try.
The peak flow meter should be used 3 times and the best result
recorded. Peak expiratory flow meter results are not as accurate as spirometry
(done in a doctor's office), but both measure lung function.
People who use a home peak flow meter need to use the same meter over
time because different brands of meters give different values for results. If
you change meters, you need to determine your personal best measurement using
the new machine.
Wash meters in soapy water every 2 weeks to prevent growth of
bacteria and fungi.
Before testing, make sure you have no food or gum in your mouth.
You can use a peak flow meter while standing or sitting up straight. But you should measure peak flow in the same position (sitting or standing) every time. Follow these steps to use a peak flow meter:
Put the pointer on the gauge of the peak flow
meter to 0.
Attach the mouthpiece to the peak flow
Take a deep breath.
Put the peak
flow meter mouthpiece in your mouth and close your lips tightly around the
outside of the mouthpiece. Don't put your tongue inside the
Breathe out as hard and as fast as you can, using a
"huff" rather than a full breath out.
Record the value on the gauge
in your asthma diary.
Move the pointer on the gauge back to 0
before you blow again.
Blow into the peak flow meter two more
times. Record your values each time. If you cough or make a mistake during the
testing, do the test over.
After you have blown into your peak flow
meter three times, record the highest value on your daily record sheet.
Primary Medical Reviewer
E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer
Robert L. Cowie, MB, FCP(SA), MD, MSc, MFOM - Pulmonology
How this information was developed to help you make better health decisions.