How does an asthma puffer actually work with a spacer?

Asthma puffers and spacers, I get asked about them alot. What does the spacer do exactly? Because it’s easier to just put the asthma puffer, or metered dose inhaler (MDI) in your pocket and not bother with a spacer. But research points to an asthma spacer being the better way to deliver asthma puffer (MDI) medication. The spacer helps mix the air with the medication so it can be breathed in and reach the narrow airways. An asthma spacer is also easier for children and for a parent or carer to assist them.

How does the asthma spacer work?

Even though asthma spacers vary in design and size, when the asthma puffer is attached they basically do the same thing. Have a look at an asthma spacer next time you have one in your hand. Without attaching the asthma puffer, breathe in and out and feel where the air travels through the device. By doing this, it will help you understand what the valves do for the asthma spacer.  Air blown into the spacer won’t come out the area that the asthma medication from the puffer comes in, it’s diverted before it goes back into the chamber by a valve near the mouth piece.

I’ve created a diagram to show you how the air and medication travel through the spacer.

• The dark blue arrows shows the fresh air breathed in via the sides of the canister.
• Light blue arrows show the breathing back into the spacer.
• The white arrows the medication from the puffer.

1. First it mix’s air with medication in the chamber after an inward breath and medication is activated from the puffer (MDI). A check valve in the spacer (just before the mouth piece) opens – allowing air and medication to travel into the airways.
2. The second thing it does, is on the outward breath the check valve will close off the chamber.  The outward breath is then diverted out of the spacer via an opening between the mouth piece and the chamber.

To learn more:

Visit the Asthma Foundation for spot on information about spacers and technique for how to use them. Your local pharmacy can help, as well as your GP.  If you have already purchased a spacer, refer back to the asthma spacer manufacturers website for further information.

I hope my illustration helps and not confuses! Let me know?

Other posts:
Asthma Spacers  – It’s all in the delivery