An inhaler is a small medical device designed to deliver a precise dose of medication directly to the lungs, the site of action for conditions like asthma and Chronic Obstructive Pulmonary Disease (COPD). This direct delivery allows the medicine to work quickly, minimizing the overall dose required and reducing systemic side effects compared to oral treatments. However, the effectiveness of this targeted therapy depends highly on the user’s technique. Improper use can result in the majority of the drug depositing in the mouth and throat rather than reaching the lower airways, leading to poor symptom control. Mastering the correct method for your specific device is paramount to achieving the full therapeutic benefit.
Understanding the Two Main Inhaler Types
Inhaler devices fall into two categories: Metered-Dose Inhalers (MDI) and Dry Powder Inhalers (DPI). The fundamental difference is how they aerosolize and deliver the medication. Metered-Dose Inhalers, often called “puffers,” use a pressurized canister and chemical propellant to release a measured dose as a fine, liquid mist.
This system requires the user to coordinate pressing the canister with a slow, steady inhalation. Dry Powder Inhalers contain medication as a fine powder. These devices are breath-actuated, meaning the user’s inspiratory effort provides the energy needed to aerosolize the powder and draw it into the lungs. This distinction means the required inhalation technique for each type is almost completely opposite.
Step-by-Step Guide for Metered-Dose Inhalers
Before using a standard Metered-Dose Inhaler without a spacer, shake the MDI vigorously for three to five seconds to ensure the medicine and propellant are mixed. If the inhaler is new or unused for several days, it requires “priming” by releasing a test spray into the air, following manufacturer instructions. Sit or stand upright and exhale slowly and completely away from the mouthpiece to empty the lungs.
Place the mouthpiece into the mouth, sealing the lips tightly around it, ensuring the tongue does not block the opening. The most challenging step, hand-breath coordination, involves simultaneously beginning a slow, deep inhalation through the mouth while firmly pressing down on the canister to release the medication. Sustain this inhalation for three to five seconds to allow the drug particles to travel deeply into the airways.
After delivery, remove the inhaler and hold your breath for up to ten seconds to allow the medication particles to settle in the lungs. Holding the breath maximizes lung deposition and increases the therapeutic effect. Finally, exhale slowly away from the device. If an additional puff is required, wait about one minute before repeating the entire process, starting with shaking the inhaler again.
Optimizing Delivery with Spacers and Dry Powder Devices
Spacers, also known as valved holding chambers, are hollow tubes that attach to an MDI and are highly recommended for use. The spacer acts as a reservoir to hold the aerosolized mist, eliminating the need for precise coordination between actuation and inhalation. When using a spacer, the MDI is actuated into the chamber, and the user takes a slow, deep breath from the mouthpiece.
Tidal breathing (multiple normal breaths) can be used if the user is unable to hold their breath, especially for children. The spacer reduces the velocity of the aerosol spray, minimizing medication impact on the back of the throat, improving lung deposition, and reducing local side effects. If the user inhales too quickly, a whistle may sound, indicating the flow rate is too high and should be slowed down.
Dry Powder Inhalers (DPIs)
The technique for a DPI is fundamentally different, relying on the user’s inspiratory flow rate to disperse the powder. After loading the dose according to the device’s specific mechanism, the user must exhale fully away from the device to prevent moisture from clumping the powder inside. Place the lips tightly around the mouthpiece and inhale rapidly and forcefully, taking a deep breath to draw the powder into the lungs.
This required inhalation must be much quicker and stronger than for an MDI, as the force of the breath breaks up the powder into breathable particles. The breath is held for up to ten seconds, similar to the MDI technique, to allow the powder to settle. Unlike MDIs, DPIs should never be shaken, as this can prematurely disperse the dose, leading to inaccurate delivery.
Troubleshooting Common Technique Errors and Device Maintenance
Frequent MDI errors include poor coordination (pressing the canister too early or late), causing the medicine to mostly settle in the throat. Another common mistake involves not exhaling fully before use, which reduces the lung capacity available for the subsequent therapeutic breath. For DPIs, the primary error is often an insufficient or slow inspiratory flow, which prevents the medicine from aerosolizing correctly and reaching the lower airways.
Holding the breath for less than the recommended five to ten seconds is a generalized error that reduces the therapeutic effect across all inhaler types. If the inhaler contains a corticosteroid, rinsing the mouth and gargling with water immediately after use and spitting it out is required. This action removes residual steroid particles from the mouth and throat, lowering the risk of developing oral candidiasis (thrush).
Device Maintenance
Monitor the dose counter on the inhaler, or keep a manual count, to ensure the device is replaced before it runs out completely. Cleaning procedures vary by device. MDIs typically require the plastic casing to be washed in warm water and air-dried weekly; the metal canister is never placed in water. DPIs should not be exposed to water, as moisture can clog the fine powder mechanism, requiring only a dry cloth to wipe the mouthpiece.