What does a spacer do in relation to a metered-dose inhaler (MDI)?

A spacer is an essential device used in conjunction with a metered-dose inhaler (MDI) to enhance the delivery of medication to the lungs. Its primary function is to collect and hold the aerosolized medication emitted from the MDI. When the patient activates the inhaler, the spacer allows the medication to disperse within its chamber before the patient inhales. This minimizes the velocity of the medication particles, enabling more efficient inhalation and reducing the likelihood of the medication depositing in the mouth and throat.

Using a spacer helps improve inhalation technique, especially in individuals who may have difficulty coordinating inhalation with actuation of the inhaler, such as young children or those with respiratory issues. By providing this collection space, the spacer ensures that a greater proportion of the medication reaches the airways and lungs, thus maximizing its therapeutic effect.