A nebulizer is a device used to administer medication as a mist inhaled into the lungs. They are commonly used to treat respiratory diseases such as asthma and COPD. Medication is added to the machine as a liquid, and then changed into a mist in order to be inhaled. This method is preferable to ingestion or other delivery methods because it targets the respiratory tract directly. This speeds the onset of the medication and reduces some side effects.
Nebulizers use oxygen, compressed air, or ultrasonic power to break up the medications into small aerosol droplets. An aerosol is a mixture of gas and liquid particles, such as mist. To inhale a medication, it’s necessary for these aerosol droplets to be extremely small, or they will only be absorbed by the mouth rather than lower airways where they are needed. Unfortunately, not all nebulizers are able to achieve the small size necessary, so some research is warranted.
Early nebulizers were powered by a hand crank that would increase the pressure of the medication, sending it through an atomizer and spraying out near the user’s mouth. Steam driven nebulizers were invented later using chemical and physical principles to atomize the liquid medication, although they were not especially efficient since droplet size was not yet understood. The water would be boiled, and the resulting steam would pass through a tube suspended in the medicine. The solution would then be drawn into the steam and inhaled by the user.
The first electrical nebulizer made pharmaceutical solutions aerosol with the power from an electric compressor. Due to the cost of these machines though, they didn’t catch on for some time. Eventually ultrasonic wave nebulizers were developed, and used for more than just medical purposes. Small parts would vibrate at very high frequencies, creating ultrasonic waves that atomize the liquid. These can be found in humidifiers and in electric cigarettes.
The most common nebulizers now in use are jet nebulizers, which use compressed air or oxygen to flow through a liquid at high velocity, creating an aerosol. Technological developments have given these a very low operational cost. It can also be more effective in serious respiratory diseases or severe asthma attacks.