The Outcome of CPAP Titration Under Sleep Endoscopy: A Randomized Controlled Crossover Trial

This is the study entitled "The outcome of CPAP titration under sleep endoscopy: A randomized controlled crossover trial". CPAP is first line golden standard treatment for Obstructive sleep apnea (OSA). However, the overall CPAP compliance is about 50%. One of the reasons responsible for the poor compliance is the inadequate pressure setting initially. Therefore, it is crucial for us to find out the adequate pressure as soon as possible. Sleep endoscopy is the way to evaluate upper airway obstruction of OSA patients. Meanwhile, the investigators used CPAP to titrate the adequate pressure to keep upper airway open under sleep endoscopy guidance. While the investigators find out this adequate pressure, the investigators set this pressure into CPAP program, which OSA patient will use for 1 month. To compare the different effect of CPAP under either auto-CPAP titration pressure or sleep endoscopy guidance pressure, those OSA patients will use auto-titration CPAP for 1 month as well. Another highlight of this study is the sedative agent-dexmedetomidine. Dexmedetomidine is a α2 antogonist, which cause patients sedative but less respiratory drive suppression. The mechanism of dexmedetomidine is more physiological for nature sleep.