Osmosis video - Respiratory: Measuring peak expiratory flow rate

Peak Expiratory Flow Rate (PEFR) is a measurement of the maximum amount of air that a person can forcefully exhale in one breath. It is typically measured using a peak flow meter, which is a handheld device made up of a mouthpiece and a built-in scale that indicates the flow rate. Measuring PEFR helps to determine the degree of airway obstruction in clients with respiratory conditions, such as asthma. When measuring PEFR, the client should take a deep breath in, up to maximal inspiration, and then exhale forcefully. This is repeated several times, and then note the highest value reached after the procedure is finished.