Which action indicates that a client understands how to use a metered-dose inhaler correctly?

The action that indicates a client understands how to use a metered-dose inhaler correctly is exhaling completely before using the inhaler. This step is crucial because it ensures that the lungs are ready to receive the medication. When the lungs are emptied of air, there is more space available for the medication, allowing for deeper inhalation and better absorption into the respiratory system. The effectiveness of inhaled medication depends significantly on the technique used, and exhaling fully prepares the airway.

While shaking the inhaler is an important step to mix the medication properly, it does not directly relate to the inhalation technique. Inhaling deeply before pressing the canister would not be effective, as the act of releasing the medication should coincide with inhalation to ensure that the medication is delivered directly into the lungs. Holding one’s breath after inhalation is also a good practice to allow the medication to settle in the lungs, but the initial action of exhaling fully is foundational to proper inhaler use.