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Southwestern United States
Information for patients with allergy and related problems
in the Southwest

Spacer Devices for Metered Dose Asthma Inhalers

Spacer devices have a chamber that receives the aerosol before it is inhaled.  They serve two functions:
a) to overcome difficulties in coordinating the timing of the inhaler actuation and inhalation, 
b) to slow down the speed of delivery of the aerosol into the mouth so that less of the drug impacts in the throat.

Spacers are only partly effective in overcoming poor timing in using inhalers: if the inhaler is actuated in exhalation instead of the beginning of inhalation, at least 50% of the dose is lost.  Some attributes of various spacers are shown in the Table.   The smaller volume spacers are appropriate for children as well as adults.  A valved chamber  with exhalation ports is useful to prevent exhalation into the chamber and allow inhalation of drug remaining in the chamber after the first inhalation.  However the valve is reported to reduce the inhaled dose. Loss of drug by deposition on the walls of the spacer can be reduced by soaking the spacer in water with household detergent and allowing it to dry without rinsing.   A flow rate signal helps to warn the user that the inhalation is too fast.  Universal inhaler adapters conform to the mouthpiece of any metered dose inhaler, whereas the others have rigid adapters that fit only one type of mouthpiece.

(For pictures, click links)

Device Use in Small Children Volume Valved Chamber Flow rate signal Inhaler adapter
ACE Yes (with mask) 170 ml Yes Yes N/A**
Aerochamber Yes (with mask) 145 ml Yes Yes Universal
Easivent Yes (with mask) 140 ml Yes Yes Universal
Ellipse No 175 ml No No Ovoid
E-Z Spacer # Yes (with mask) 700 ml No* No N/A**
Inspirease # No 700 ml No* Yes N/A**
Medispacer Yes (with mask) 175 ml Yes Yes N/A**
LiteAire^ No 158 ml Yes No Universal
Optichamber Yes (with mask) 218 ml Yes Yes Universal
Nebuhaler No 750 ml Yes No Oval
Ventahaler No 750 ml Yes No Oval
RiteFlo No 140 ml No No Universal

*   collapsible chamber
** inhaler canister fits directly into the spacer device
collapsible - fits in shirt pocket
#   compact
†   flow rate limited to the recommended 15-30 L/min, obviating need for a flow rate signal

Further Reading:
Beaucage D, Nesbitt S.  Using inhalation devices. in Comprehensive Management of Chronic Obstructive Pulmonary Disease, Chapter 6.  Bourbeau J, Nault D, Borycki E (eds) BC Decker, Hamilton 2002.


Disclaimer:   This site is for educational purposes only.  Any information that you have found in this web site is not intended to replace medical care or advice given to you by your own physicians. You should consider consulting your local medical library and other web sites for additional information. 

Comments and suggestions welcome!   Email:
Content Owner:  Michael J. Schumacher, MB, FRACP, The University of Arizona

Updated 8/2008