Medical Advice >> Pediatric Advisor

What is the purpose of the peak flow meter?

The peak flow meter measures how fast you can exhale air after taking a deep breath.

Measuring the peak flow regularly can help you:

• predict an asthma episode (if the peak flow is dropping)
• see how well your medications are working
• see if you are getting better after an asthma attack.

Your health care provider may tell you to call him or her, or to go directly to the emergency room, if the peak flow measurement goes below a certain level.

When should the peak flow meter be used?

Use your peak flow meter according to your health care provider's instructions. For example, your provider may ask you to measure your peak flow once or twice a day (morning and evening) and to record the measurements in a daily log. The log helps your provider know how well your medicines are working. Also, measure your peak flow when you have an acute asthma attack.

What is normal peak flow?

Most peak flow meters come with a chart that helps you determine the normal range for your age and height. Ask your health care provider how close to normal you should expect to get.

How is the peak flow meter used?

Each brand of peak flow meter works a little differently. Carefully read and follow the instructions included with your meter.

General instructions are:

1. If your peak flow meter comes with a separate mouthpiece, put it on the meter.

2. Place the marker at the bottom of the numbered scale (zero or the lowest number on the scale).

3. Hold the peak flow meter upright, being careful that fingers do not block the opening.

4. Stand up straight and breathe in as deeply as you can. Put the mouthpiece into your mouth beyond your teeth and make a tight seal around the mouthpiece with your lips.

5. Blow out as hard and fast as you can.

6. The marker will move up the scale and stop at the point that is the peak flow measurement. Note the measurement, return the marker to the bottom of the scale, and repeat steps 3 through 6 two more times.

7. Write down the date, time, and highest of the 3 measurements in the log.

When and how should the peak flow meter be cleaned?

If your meter has a separate mouthpiece, clean the mouthpiece once a week with warm water and dry it thoroughly.

This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.