Aerosols in the Health Care Field

:: Section 3

The key issue in using MDI devices is the difficulty of patient use. Failing to coordinate inhalation and hand actuation of the inhalation is the most commonly encountered problem. Patients often actuate before or after the breath, rather than during the breath. Many patients may also cease inspiration as the cold aerosol strikes the throat (also called "Cold Freon Effects"). They may also forget to hold their breath after inhalation.

Some other limitations and problems include:

• Drug concentrations are constant, and can not be adjusted for individual patients.
• Difficult to determine accurately if the canister depletion.
• Patients may fail to shake and mix canister contents.
• Some patients may develop reactions to the propellants.
• High impaction in the oropharyngeal region may result in loss.