Auto CPAP (APAP) stands for Automatic Positive Airway Pressure and relies on the same basic principles as a CPAP (continuous positive airway pressure) machine. Similar to the CPAP devices, APAP machines are a non-invasive treatment for sleep apnea that deliver pressurized air, via a mask, to keep your airways free of obstructions as you sleep. The air pressure delivered from the machines is adjusted automatically and acts as a splint, keeping your throat from collapsing in on itself so that you can breathe freely through the night without any apnea events.