The treatment of Sleep Apnea Syndrome: looking for new answers for old problems.

Obstructive sleep apnea syndrome (OSA) is characterized by repeated episodes of upper airway occlusion during sleep, resulting in transient asphyxia until an arousal restores airway patency. The consequences of these events are profound, including sleep fragmentation, increased blood pressure, daytime sleepiness, quality of life impairment and a greater risk of motor vehicle accidents. Continuous positive airway pressure (CPAP) therapy is generally considered as the first-line treatment for OSA. Standard CPAP devices deliver a constant positive pressure that acts as a pneumatic splint, preventing upper airway collapse. In patients with OSA, CPAP is highly effective in eliminating obstructive events, decreasing blood pressure, reducing sleepiness and improving quality of life [1-2]. CPAP levels are generally set during an attended laboratory polysomnography to eliminate apneas, hypopneas, snoring, and flow limitation in all positions and sleep stages [3]. Therefore, since pressure requirement will change during the night, according to sleep stage and body position, the set pressure is usually higher than the level actually able to maintain airway patency for at least a portion of the night [4]. The use for the whole night of a pressure level higher than the minimum needed could potentially increase mask leaks, mouth leaks, pressure intolerance, and theoretically reduce acceptance and adherence to treatment in some patients. Autoadjusting CPAP devices (APAP) have