Definition & Types

WHAT IS A NEBULIZER?

A nebulizer is an electronic device that converts liquid medication into a fine aerosol or mist so that it can be delivered to the lungs.

There are various mechanisms by which the liquid drug can be aerosolized. Depending on these mechanisms, the nebulizers are categorized into various types (elaborated below).

TYPES OF NEBULIZERS​

Mechanism:
Jet nebulizers use pressurized gas/air to draw the liquid medication from the nebulizer cup through a thin capillary.  The pressurized air or gas is provided by the compressor. The liquid medication is converted into aerosol or mist comprising small and large particles. Smaller particles are inhaled, and larger particles hit the walls inside the medication cup and enter back into the reservoir.

Advantages:

• Any type of liquid medicine (solution or suspension) can be nebulized.
• Jet nebulizers are less expensive.

Limitations:

• Less portable.
• Assembling the nebulizer can be difficult for some patients who suffer from physical and cognitive impairment.
• Known to have variability in aerosol output.
• Causes cooling of the solution when in use.

Mechanism:
Mesh nebulizers use a mesh or aperture plate to generate the aerosol or mist.

Advantages:

• Has an improved and consistent aerosol generating efficiency.
• Nebulization can be achieved using a low drug volume.
• Small size, lightweight, and battery-operated system makes it easily portable and handy.

Limitations:

• Due to more efficiency, using a mesh nebulizer requires dose adjustment to prevent adverse effects.
• Cannot be used to deliver thicker liquid suspensions (can clog the mesh pores).
• Can be difficult to clean.
• More expensive than jet nebulizers.

Mechanism:
 Ultrasonic nebulizers use high-frequency vibrations generated by a piezoelectric crystal to produce the aerosol.

Advantages:

• Used to deliver inhaled medicines and saline for sputum induction (a procedure to collect respiratory secretions).

Limitations:

• Cannot be used to deliver viscous solutions or suspensions.
• Has a large residual volume (leftover medicine that cannot be nebulized, resulting in drug wastage).
• Generates heat when in use; hence, not suitable for heat-sensitive material such as proteins and suspensions.

Mechanism:
Smart nebulizers have an inbuilt automatic sensor that senses your breathing and determines when the aerosol should be delivered. Some smart nebulizers also keep a log of the usage, which helps in patient adherence to therapy.

Advantages:

• Reduces loss of drug to the surroundings.
• Reduces drug delivery variation.
• Improves patient adherence to the treatment regimen.
• Better control over the delivery of expensive drugs (such as proteins).

Limitations:

• More expensive than other nebulizers.