Theory – PEFR – (peak expiratory flow rate) is a measure of the maximum speed of expiration. It is measured in litres/minute. It is used to asses if bronchoconstriction is reversible – i.e. the test is diagnostic for asthma. Not only is it used to diagnose asthma, but it can also be used to monitor the effectiveness of drugs.
Introduce yourself, check you have the right patient, explain what you are going to do and why!
Make sure the patient's finger is not covering the meter, as this can block the slider moving up the scale.
Also, make the sure patient's finger does not cover any of the slide scale at all – as sometimes this can create a 'spring effect; and the slider can zoom off and give a higher reading than the true value.
Tell the patient to take a deep breath in, and then make a tight seal around the mouth piece, then blow out as hard and as fast as they can.
You should do a minimum of three readings. If the reading differ wildly, then you should continue until you have three roughly consistent readings. If the results vary like this it is likely the patient is not following the right procedure.
DEMONSTRATE THE TECHNIQUE, AND THEN ASK THE PATIENT TO SHOW YOU – so you know they are doing it correctly.