CPAP and APAP devices
There are several manufacturers of CPAP devices. There are two major types of CPAP devices used for people with OSA. "Fixed dose" CPAP are set to provides a constant air pressure somewhere in the range of 4-20 cm of water. The setting chosen is prescribed by the treating physician and is based on the pressure needed to open the collapsed airway during sleep as measured during a titration study. "Auto-titrating" CPAP (APAP) is a newer type of CPAP that provides gradually increasing pressures until the airway opens and then maintains the lowest pressure needed to keep the airway open. APAP has the advantage adjusting to the patient's needs overnight and over time. APAP does not require a titration study. Studies have shown that fixed dose CPAP and APAP are equally effective and patients generally prefer APAP.