A metered-dose inhaler (MDI) is a pressurized canister that delivers a precise amount of aerosolized medication with each press, often called a puff. A spacer is a tube or chamber that attaches to the MDI, holding the medication cloud after actuation for slower inhalation. A face mask forms a seal over the nose and mouth and is recommended for individuals who cannot coordinate the MDI press with a deep, slow breath, such as young children. This combination enhances medication delivery to the lungs by reducing the amount that deposits prematurely in the mouth and throat. The spacer and mask serve as a reservoir, making the inhalation process simpler and more effective.
Preparing the Device for Use
Before use, confirm the MDI is within its expiration date and check the dose counter, if present, to ensure an adequate supply of medication remains. The inhaler must be shaken vigorously for five to ten seconds immediately before each use to ensure the medicine and propellant are properly mixed for a consistent dose. Remove the caps from both the MDI and the spacer-mask unit.
If the inhaler is brand new, unused for a week or longer, or has been dropped, it requires priming to guarantee a full dose is delivered. Priming involves spraying a small number of puffs (typically two to four) into the air away from the face, following manufacturer instructions. The MDI canister should then be firmly inserted into the designated opening at the back of the spacer chamber.
Step-by-Step Administration Technique
Sit or stand upright and gently place the mask over the face, ensuring it covers both the nose and mouth. Create a complete and tight seal between the edges of the mask and the skin, as any leak reduces the amount of medication delivered to the airways. The person assisting should hold the spacer and mask securely in place until the treatment is complete.
After the seal is established, press the MDI canister once to release a single puff of medication into the spacer chamber. For mask users, the recommended technique is tidal breathing, which involves taking six to ten slow, normal breaths through the device. This allows the aerosolized medication suspended within the chamber to be drawn into the lungs over multiple respiratory cycles.
Some valved spacers produce a soft whistling sound if inhalation is too rapid or forceful. The breathing rate should be slowed down if this occurs, ensuring the medication is drawn deep into the lungs rather than deposited in the upper airway. If the treatment requires more than one puff, wait 30 to 60 seconds before shaking the inhaler again and repeating the process of sealing the mask and actuating the MDI.
Essential Maintenance and Storage
The spacer and mask unit should be cleaned routinely, typically once a week, to prevent the buildup of static electricity and medication residue. Static charge causes medicine particles to stick to the inside walls of the chamber, reducing the amount available for inhalation. Cleaning is accomplished by dismantling the spacer and soaking all plastic parts in warm water mixed with a mild dish detergent.
Avoid scrubbing or wiping the inside of the spacer, as this generates static and potentially damages the one-way valve. After soaking, gently shake the parts to remove excess water and allow them to air-dry completely in a clean environment, since towel-drying introduces lint and static. Once fully dry, the device should be reassembled and stored away from extreme temperatures and dust, preferably in a plastic-free, breathable bag. The spacer and mask should be checked periodically for cracks or brittle components and replaced every 12 months to maintain optimal function.