A nebulizer is a medical device designed solely for medication delivery, not for the production of oxygen. It transforms liquid medication into a fine, breathable mist, known as an aerosol, which a patient inhales directly into the lungs. This process is effective for treating respiratory conditions such as asthma, Chronic Obstructive Pulmonary Disease (COPD), and cystic fibrosis. The device relies on an external power source, typically an electrical compressor or a battery, to convert the liquid formulation into inhalable particles.
How Nebulizers Turn Liquid Medicine into Mist
The purpose of a nebulizer is to create an aerosol, allowing for the direct absorption of medicine into the respiratory system. Aerosol particle size is precisely controlled, often ranging between 1 and 5 micrometers, to ensure they travel deeply into the lower airways and alveoli. This targeted delivery is often more effective than an inhaler for patients who have difficulty coordinating their breath or during a severe respiratory event.
There are three primary types of nebulizer technology, each using a distinct method to achieve aerosolization.
Jet Nebulizers
Jet nebulizers are the most common, utilizing a stream of compressed gas to break the liquid medication into fine droplets through a principle similar to an atomizer. The compressor generates a high-velocity gas flow that passes over the liquid reservoir, shearing the fluid into the desired fine mist.
Ultrasonic and Mesh Nebulizers
A second type is the ultrasonic nebulizer, which does not rely on compressed gas but instead uses high-frequency sound waves. A crystal oscillator vibrates rapidly, creating mechanical energy that generates a liquid “fountain,” with the unstable peaks breaking off into aerosol droplets. The third and most modern type is the mesh nebulizer, which forces the liquid medication through a fine mesh or plate containing thousands of microscopic holes. This mechanical action produces a very fine mist with high efficiency, often making mesh nebulizers more portable and quieter than their jet counterparts.
Understanding the Gas Source: Air or External Oxygen?
Confusion arises because jet nebulizers require a gas source to function, but the standard source is compressed room air, not pure oxygen. The electrical compressor draws in ambient air, compresses it, and uses that air as the propellant to create the aerosol mist. This process delivers the medication suspended in normal air, which contains approximately 21% oxygen.
In specific clinical circumstances, a nebulizer may be intentionally connected to an external oxygen source, such as a tank or concentrator. This occurs when a patient is already receiving supplemental oxygen therapy due to low blood oxygen levels (hypoxemia). In this scenario, the oxygen flow is substituted for the compressed air flow to power the nebulization process.
The oxygen acts solely as the driving gas or propellant for the nebulizer, not as a product generated by the device itself. While using oxygen as the propellant can transiently improve a patient’s oxygen saturation during an acute asthma attack, it is generally avoided in conditions like COPD exacerbation. Using pure oxygen can lead to a dangerous increase in carbon dioxide levels in the blood. For this reason, many home nebulizers are designed to use only compressed air to ensure patient safety.
Devices That Actually Deliver Therapeutic Oxygen
Unlike the nebulizer, which delivers medication, other medical equipment is specifically designed to provide therapeutic oxygen. These devices work by concentrating oxygen from the surrounding air or by storing it in a highly pure form. Oxygen concentrators are the most common home devices, operating by drawing in room air and filtering out nitrogen using a sieve bed material.
This process delivers a continuous flow of air highly enriched with oxygen, typically ranging from 85% to 95% purity. The concentrated oxygen is delivered to the patient through a nasal cannula or a face mask. Because they run on electricity, concentrators provide an indefinite supply of oxygen without needing refills.
Therapeutic oxygen can also be delivered from compressed gas cylinders or liquid oxygen systems, which store pure, pre-filled medical-grade oxygen. Cylinders contain oxygen pressurized into a metal tank. Liquid oxygen systems store the gas in a super-cooled liquid state, allowing for a large volume of oxygen to be stored in a relatively small container. These systems require a separate delivery device, such as a nasal cannula, to carry the supplemental oxygen to the patient’s respiratory tract.