Forced Expiration Technique

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Forced Expiration Technique 2017-04-27T04:43:29+00:00

Forced Expiration Technique (FET)

An outline of the technique is detailed in FET section

How to perform the technique?: (see FET video)

Huffing with tube


Huffs are described as either ‘low volume’ or ‘high volume’ depending on where the sputum is and from where it is initiated.

Low-mid lung volume huffs (ie smaller breaths) may help to access and shift sputum from distal airways; a high volume huff (larger inspiration) may be more useful where the sputum shift occurs in the upper airway moving the sputum into the mouth to be expectorated.

This is a difficult concept for many children when learning the technique. Huffing from any volume can be used providing it reaches the volume necessary to access secretions.

Physiotherapists can start to introduce the concept of huffing during the toddler years.

Huffing tips 

A useful description for children is that huffing is like fogging up a mirror and can be easy to teach a young child

Use cottonwool or tissue paper characters to encourage huffing through a huff tube to ‘huff’ the lighter objects away

There should not be any harsh noises with huffing. If this happens, the patient hasn’t used the ‘O’ shape or may be squeezing too hard to push the air out

Learning to use the different grading in huffing is a very important skill for the child/adolescents to learn

For patients with unstable or floppy airways, huffing into a PEP mask can be very useful to prevent airway collapse

Any patient either new to the FET, or have been using the FET for a long time,  still need regular review or refinement of this technique


Huffing with tube two children