How Does a CPAP Machine Work to Treat Sleep Apnea?

If you have been told that you need to use a (continuous positive airway pressure ) CPAP machine to treat your sleep apnea, you may wonder how a CPAP machine works.

Here, you’ll learn how these devices relieve snoring and sleep apnea with pressurized air and what special considerations may be necessary if you have central sleep apnea.

How CPAP Works

Modern CPAP machines work based on the same principles as the initial devices developed by Dr. Sullivan. The pressures are now generated with smaller, quieter motors. Nevertheless, room air (not oxygen) is taken in through a filter and pressurized according to settings prescribed by your sleep specialist. Machines are set to deliver pressure from 4 centimeters of water pressure (CWP)2 up to a maximum of 25 CWP. This air is often passed through a heated humidifier and delivered via tubing to the mask interface.

The constant flow of pressurized air creates a cushion along the upper airway. Some have described it as a pneumatic (air) splint that keeps the throat from collapsing. This prevents the soft palate, uvula, and tongue from shifting into the airway. It reduces the vibration that creates the sound of snoring. It may relieve swelling within the nose and clear out mucus from along the airway. By supporting the airway, breathing normalizes and sleep quality improves as fragmented sleep resolves. Oxygen levels can be maintained. The serious consequences of sleep apnea can be averted.

Automatic CPAP machines vary slightly in that they can detect a collapse of the airway by measuring resistance and react by increasing the pressure as needed during the night to further resolve the sleep apnea. These devices will also test lower pressures and adjust downward if possible.