spacer

A spacer is a device used to increase the ease of giving aerosolized medication from a metered-dose inhaler (MDI). It adds space in the form of a tube or "chamber" between the mouth and canister of medication. Most spacers have a one-way valve that allows the person to inhale the medication while inhaling and exhaling normally; these are often referred to as valved holding chambers (VHC).
A number of brand names exist including AeroChamber, InspirEase and Volumatic. They can also be made from a 500 mL plastic bottle, which works just as well.
Spacers help those unable to breathe deeply, as well as those unable to synchronize their breathing so that they inhale just as the MDI is actuated; the latter is known as poor "hand-lung coordination".

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