Correct Technique for Using a Metered-Dose Inhaler (MDI) with a Spacer
When using an MDI with a spacer or valved holding chamber, actuate only once into the spacer, begin a slow deep inhalation immediately after actuation, and hold your breath for 10 seconds after completing the inhalation. 1, 2
Preparation Steps
- Shake the inhaler vigorously before each use to ensure proper medication mixing 2
- Prime the inhaler if it is new or has not been used recently, following the manufacturer's instructions 2
- Assemble the spacer by attaching it firmly to the MDI mouthpiece 1
- Clean plastic spacers monthly by rinsing with dilute dishwashing detergent (1 part detergent to 5,000 parts water) and allowing them to drip-dry; this reduces static charge and improves drug delivery 1, 2
Step-by-Step Inhalation Technique
Positioning
- Place the spacer mouthpiece between your lips and teeth to create a tight seal 1
- For children under 4 years or patients unable to use a mouthpiece, use a tight-fitting face mask over the nose and mouth 1, 2
Actuation and Inhalation
- Actuate the MDI canister once into the spacer—never fire multiple puffs into the spacer at the same time 1, 2
- Begin a slow, deep inhalation immediately after actuation (approximately 30 L/min over 3–5 seconds); do not delay 1, 2
- Continue inhaling slowly and deeply after actuation; do not stop at the moment you hear or feel the spray 2
Breath Hold
- Hold your breath for approximately 10 seconds after completing the inhalation to allow medication deposition in the airways 1, 2
Multiple Puffs
- If more than one puff is prescribed, wait 10–15 seconds between puffs and repeat the entire sequence for each puff 2
- Each puff requires a separate actuation into the spacer followed by immediate inhalation 1
Post-Inhalation Care
- Rinse your mouth and spit after using inhaled corticosteroids to reduce systemic absorption and prevent oral thrush 1, 2
- Remove the spacer from the MDI after completing all prescribed puffs 1
Why a Spacer Is Essential
Spacers are mandatory for all children under 4 years and strongly recommended for elderly patients with poor coordination, patients using inhaled corticosteroids, and anyone unable to coordinate actuation with inhalation 1, 2. Compared with an MDI alone, spacers minimize coordination difficulties, reduce oropharyngeal deposition, and often increase lung deposition 3. In patients with severe acute asthma, an MDI plus large-volume spacer may be a viable alternative to a nebulizer for delivering large bronchodilator doses 3.
Common Pitfalls to Avoid
- Do not actuate multiple puffs into the spacer at once—this dramatically reduces drug delivery because the medication settles on the spacer walls 1, 2
- Do not delay inhalation after actuation—begin breathing in immediately to capture the aerosol cloud before it settles 1, 2
- Do not inhale too rapidly—a slow, controlled inhalation (30 L/min over 3–5 seconds) optimizes lung deposition 1, 2
- Do not skip the breath hold—holding your breath for 10 seconds is critical for medication to deposit in the airways 1, 2
- Do not neglect spacer cleaning—static charge on unwashed plastic spacers reduces drug delivery by up to 50% 1, 2
Training and Verification
- The first dose should be administered under direct supervision before the patient uses the device at home 1, 2
- Inhaler technique should be reassessed at every clinical visit because technique commonly deteriorates over time 1, 2
Special Populations
Children Under 4 Years
- Must use a spacer with a tight-fitting face mask because they cannot generate sufficient inspiratory flow or coordinate actuation 1, 2
Elderly Patients
- Those with weak fingers, poor coordination, or cognitive impairment should use a spacer to improve technique reliability 4, 1, 2