How should a peak expiratory flow meter (PEFM) be used?

Using a peak expiratory flow meter (PEFM) is critical for monitoring respiratory function, especially in individuals with asthma or other chronic respiratory conditions. The correct method involves forcefully exhaling for a brief period, specifically for around one second, to obtain an accurate reading of the peak expiratory flow rate (PEFR).

The technique of forcefully exhaling maximizes the flow of air expelled from the lungs, allowing the meter to measure the highest speed of expiration. This brief, powerful exhalation helps to reflect the function of the airways and can reveal any obstruction or constriction present in conditions like asthma.

Inhalation methods, such as taking a deep breath and holding it, do not yield meaningful data since they do not engage the necessary airflow dynamics needed for accurate PEFR measurements. Similarly, attempting to inhale through the meter does not work as it is designed specifically for the measurement of exhalation. Thus, the correct use of a PEFM revolves around the technique of forceful exhalation for about one second to capture the peak expiratory flow effectively.