Describe Peak Expiratory Flow

Question 1

What is peak expiratory flow?

Answer 1

It records the maximum speed of air flow during forced expiration.
It is measured in litres per minute using a peak flow meter and is only attained for a fraction of a second.
Normal peak flow values vary with age, sex and physical build.
Peak flow depends mainly on the diameter of the larger airways: if they are constructed or obstructed, peak flow decreases and so regular measurements are most useful in assessing gluing function in obstructive respiratory disorders e.g asthma