1. What is a peak flow meter?
A peak flow meter is a small, easy-to-use instrument that measures your
peak expiratory flow · a number that tells you how fast you can
blow out air after a maximum inhalation. It reveals how well your lungs
are working. This number is very useful for you and your doctors.
Sometimes peak flow numbers will decrease hours, or even a day or two,
before other asthma symptoms become evident. When you monitor peak flow
numbers on a daily (or regular) basis, you can identify this drop and
take steps to prevent an asthma episode. The peak flow numbers, along
with watching for asthma symptoms can be used to make decisions about
asthma treatment.
You and your doctor may find it easier to develop an asthma management
plan for you if you check peak flows on a routine basis. Also, it is important
to talk with your doctor about the steps you should take when your peak
flow number drops.
2. Who needs a peak flow meter?
Adults and children (over 5 years of age) who require medication for asthma
on a daily or near-daily basis.
3. What is my Personal Best?
How do I establish my Personal Best? The highest number regularly blown
is your personal best. This is done by recording the peak flow values
for two weeks first thing in the morning before taking any medications
and late afternoon when your asthma is under control.
Once you know your personal best, it may be helpful for you and your
doctor to use peak flows numbers for your treatment "zones".
Zones will help you decide what to do when you have changes with your
asthma The zone system can be compared to the colors of a traffic light. 4. How do I use a peak flow meter?
Stand up or sit up straight.
Slide indicator to base of meter.
Take in deep breath.
Place mouthpiece in mouth and seal lips around it.
Blow out as hard and fast as you can (one quick blow).
Repeat process 2 more times.
Select highest number of the 3 efforts.
Record this number on your peak flow diary or on a graph.
5. How often should I check my peak flow?
The peak flow should be checked once a day (morning or evening) if the
numbers do not change much from time to time. When you are doing well
you can use the peak flow meter two times during the week and once on
the weekend.
Check your peak flow number more often when you :
Begin to wake at night with asthma symptoms
Are having more daytime asthma symptoms
Have a respiratory infection (a cold)
When you are sick or have asthma symptoms to check your peak flow at least
twice a day (once in the morning and once in the evening).
Need to use "rescue medicine". This is medicine prescribed by
your doctor to be used for quick relief of asthma symptoms. If you can,
check your peak flow before taking the rescue medicine. Then check it
again 20-30 minutes later.
6. When should I report Peak Flow numbers to my doctor?
Take your peak flow meter and Asthma Health Diary with you each time you
visit with your doctor or nurse. If you have an Asthma Action Plan from
your doctor, follow the Plan for each peak flow zone.
Compare your peak flow numbers to your Personal Best:
If your peak flow is less than 80% of your Personal Best, take your rescue
medication. Wait 20 to 30 minutes and check your peak flow again. If your
peak flow is not back above 80%, report this to your doctor. If your peak
flow is back above 80%, recheck your peak flow about every 4 hours for
a day or so. Call your doctor if you continue to need rescue medicine.
If your peak flow is less than 60% consider this an emergency: Take your
rescue medicine, and call your doctor or go to the Emergency Room right
away! Your peak flow meter is only an aide to you. Do not rely on your
peak flow numbers alone when deciding whether to take your rescue medicine
or call your doctor. Your symptoms also need to be considered.
7. How do I keep track of my peak flow numbers?
Write your peak flow numbers on your peak flow sheet or Asthma Health
Diary. Be sure to write down any peak flows that are different from your
usual daily readings. Record the date, time, and peak flow numbers. Also
note any changes in how you feel or changes in your medicines. List anything
you think may be making your asthma worse.
8. What are some signs that my asthma is getting worse?
In addition to measuring your peak flow on a daily basis, you need to
look out for early warning signs of an asthma attack. Early warning signs
of an asthma attack are:
Runny, stuffy nose
Fatigue
Chin or throat itches
Headache
Moodiness
Cough with activity or laughing
Wheezing with activity
Waking up at night or early morning with a cough or wheeze
Faster breathing rate
Irritability
Babies may be fussy or may not want to eat. They may begin to cough when
they cry. Babies may also have noisy, wheezy breathing when they are resting.
They may have a faster breathing rate or difficulty feeding and may prefer
sitting to lying down.
(*Portions of this page have been derived from http://asthma.nationaljewish.org/living/tools/peakflow.php)
*DISCLAIMER This site is not meant to diagnose your condition.
The information here does not necessarily pertain to all individuals and
should not replace the advice of your physician. Please contact your doctor
with any questions.