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Spirometry Tips - How To Do It and Common Pitfalls and
Problems
How to Do It
To ensure an acceptable result, the FVC manoeuvre must be performed with maximum effort immediately following a
maximum inspiration; it should have a rapid start and the spirogram should be a smooth continuous curve.
To achieve good results, carefully explain the procedure to the patient, ensuring that he/she is sitting erect with feet
firmly on the floor (the most comfortable position). Note that for child patients, vital capacity can be greater in the
standing position. Apply a nose clip to the patients nose (this is recommended but not essential) and urge the
patient to:
°
breathe in fully;
°
seal his/her lips around the mouthpiece;
°
blast air out as fast and as far as you can until the lungs are completely empty;
°
breathe in again as forcibly and fully as possible.
If only peak expiratory flow is being measured then the patient need only exhale for a couple of seconds. Essentials
are:
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a good seal on the mouthpiece and
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very vigorous effort right from the start of the manoeuvre and continuing until absolutely no more air can be
exhaled.
°
no leaning forward during the test.
