The left margin of a peak flow chart shows a scale from 0 liters per minute to 600 liters per minute, while the top row represents the date and time; the plots on the chart indicate the highest reading from a peak flow meter on the designated day and time, the American Lung Association explains. The bottom of the chart provides an area to list comments, including how one feels that day.Continue Reading
To use a peak flow meter, ensure the sliding marker is at the bottom of the numbered scale, take a deep breath, put the mouthpiece in your mouth and breath out as hard as possible as quickly as possible, as indicated by American Lung Association. Repeat three times. Record the highest number achieved. For the most accurate results, perform the test at the same time each day, and tightly close your lips around the mouthpiece.
Doctors predominately prescribe peak flow meters to asthmatics with moderate to severe asthma that is managed with daily medication, notes the American Lung Association. Doctors use readings from peak flow meters to adjust medication dosages, watch for trends of worsening symptoms, help determine when the use of rescue medicine is necessary and help identify agents triggering asthma exacerbation. Because "normal" peak flow rates vary from person to person, doctors define three zones based on the average peak flow rates of individual patients. The green zone indicates the asthma is under control, while the yellow zone signifies that the patient needs extra medication to prevent further decline. The patient needs immediate medical attention if his highest peak flow falls within the red zone.Learn more about Medical Ranges & Levels