What is the correct first step in using a Metered Dose Inhaler (MDI) without a spacer?

The first step in using a Metered Dose Inhaler (MDI) without a spacer is to remove the inhaler cap and shake the inhaler. This action ensures that the medication within the inhaler is properly mixed and aerated, which is critical for delivering a consistent dose. Shaking the inhaler helps to suspend the medication evenly in the propellant, ensuring that the proper dose is delivered when the inhaler is used.

Using a MDI without a spacer requires that the medication is adequately mixed; otherwise, the delivery may be ineffective and may not provide the desired therapeutic response. Once the inhaler is shaken and the cap is removed, the user can then position the inhaler appropriately and proceed with the proper technique to deliver the medication.