September 24, 2009 2 min read

MDI (Metered Dose Inhaler):

A Metered Dose Inhaler, commonly referred to as an MDI, is a common treatment for respiratory symptoms such as asthma.  An MDI can be used on a daily or as-needed basis.  Medication is stored inside the MDI's canister, which is depressed to release the medication through a specially designed nozzle.  The nozzle breaks the liquid medication into an aerosol optimally sized to reach the lungs.  Traditionally, the medication has been propelled through the nozzle by CFCs (Chlorofluorocarbons), but recent FDA guidelines mandate that manufacturers use the environmentally safe HFA (Hydrofluoroalkane) propellants.

Why use a holding chamber?

When a physician prescribes an MDI (Metered Dose Inhaler), they will most likely inform the patient about the use of a holding chamber.  When MDI's are used alone, medication delivery relies on patient technique, which is inconsistent and when performed wrong can result in great loss of medication.  This is especially true for very young or elderly patients, as they often lack the proper coordination to optimize their medication inhalation.

A holding chamber increases the medication delivery by allowing the MDI’s aerosol to be suspended on the inside of the chamber for a brief moment, providing more medication available for patient inhalation.  The results have been clinically proven that using holding chambers with MDI's provide more medication for the patient than when using the MDI alone.

The non electrostatic walls of the PARI Vortex® Non Electrostatic Valved Holding Chamber do not attract medication, whereas the conventional plastic chambers’ static walls do.  This is very important as MDIs are now formulated with HFA propellants, which have a higher static charge, potentially causing high medication loss in conventional static-charged plastic chambers.