Function
Peak flow readings are higher when patients are well, and lower when the airways are constricted. From changes in recorded values, patients and doctors may determine lung functionality, severity of asthma symptoms, and treatment options.
First measure of precaution would be to check patient for signs and symptoms of asthmatic hypervolemia. This would indicate whether or not to even continue with the Peak Flow Meter procedure. Measurement of PEFR requires training to correctly use a meter and the normal expected value depends on a patient's sex, age and height. It is classically reduced in obstructive lung disorders such as asthma.
Due to the wide range of ‘normal' values and high degree of variability, peak flow is not the recommended test to identify asthma. However, it can be useful in some circumstances.
A small proportion of people with asthma may benefit from regular peak flow monitoring. When monitoring is recommended, it is usually done in addition to reviewing asthma symptoms and frequency of reliever medication use.
When peak flow is being monitored regularly, the results may be recorded on a peak flow chart.
It is important to use the same peak flow meter every time.
Read more about this topic: Peak Expiratory Flow
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