Measuring Up Asthma With Peak Flow Meters


Vol. 13 •Issue 5 • Page 32
Patient Primer

Measuring Up Asthma With Peak Flow Meters

A peak flow meter is a small device that measures how fast you can blow air out of your lungs after taking a deep breath. It can help to predict an asthma episode, let you know how well your medications are working, and tell you if your lungs are improving after an asthma attack.

Children as young as 5 years old can use peak flow meters to manage their asthma, and some older patients with chronic bronchitis and emphysema have benefited from their use.

Peak flow meters are provided in two different ranges. A low range meter is for small children, and a standard range meter is for older children, teenagers and adults.

Electronic and mechanical peak flow meters are available and each operates differently. Talk to your physician or pharmacist about which device is right for you, and make sure to follow the manufacturer’s instructions.

USING YOUR PEAK FLOW METER

To measure your peak flow, first remove any food or gum from your mouth. Hold the peak flow meter, making sure that your fingers don’t block the opening. Stand or sit up straight, and take a deep breath, completely filling your lungs with air. Put the mouthpiece in your mouth, making a seal with your lips, and blow out as hard and fast as you can. The highest number recorded by the device is your peak flow measurement.

Note the measurement, and then repeat this process two more times. Write down the date, time and highest of the three measurements in your asthma diary.

The highest number blown regularly is your personal best. This number will be helpful to you and your doctor when determining your treatment zones in your asthma management plan. These zones help you decide what to do when you have changes in your asthma.

Generally, peak flow zones are given the colors of a traffic light: green, yellow and red. If your peak flow falls into the green zone (about 80 percent to 100 percent of your normal peak flow), your asthma and its symptoms are under control, and it’s advisable to continue with your prescribed therapy.

If your peak flow falls into the yellow zone (about 50 percent to 80 percent of your normal peak flow), it’s normally a sign that your airways are narrowing. Talk to your physician to see if increased medications are needed to prevent an attack.

A measurement less than 50 percent of your normal peak flow puts you in the red zone. You should take rescue medications right away because severe narrowing of the airway may be occurring. Call your doctor immediately.

REGULAR MONITORING

Use your peak flow meter daily when you’re doing well. This will tell you how well-controlled your asthma is and give you the earliest clues of an asthma flare-up. It’s suggested that you check your peak flow more often if you begin to wake at night with asthma symptoms, have a respiratory infection, or have more daytime symptoms than usual.

Sometimes peak flow numbers will decrease a few hours or a day or two before other asthma symptoms settle in. When you monitor your peak flow on a regular basis, you can identify the trend, take your medication as directed by your physician, and head off an asthma episode.

Editor’s note: Information adapted from the American Lung Association, National Jewish Medical and Research Center, and the University of Michigan Health System.

Debra Yemenijian is assistant editor of ADVANCE. She can be reached at [email protected].