Outcome of Continuous Positive Airway Pressure Treatment with Suboptimal Pressure in Obstructive Sleep Apnea

Continuous positive airway pressure (CPAP) is the treatment of choice for obstructive sleep apnea (OSA) and is highly effective particularly in moderate-to-severe OSA, defined as an apnea-hypopnea index (AHI) exceeding 15/h.1,2 CPAP functions as a “pneumatic splint” by delivering an intraluminal pressure, thereby preventing the upper airway from collapsing during sleep in OSA.3 Following diagnostic polysomnography (PSG), patients who meet the diagnostic criteria for OSA and is regarded as candidates for CPAP and undergo CPAP titration in the sleep laboratory. Although the optimal end point of titration has not been scientifically determined, most laboratories titrate to eliminate obstructive apnea, hypopnea, snoring, oxygen desaturation, and respiratory effort-related arousals.4 The target AHI with CPAP treatment is usually between 5 and 10/h.5 However, during positive pressure titration, it may be difficult to determine the optimal pressure in some patients. If the pressure is too low, it fails to eliminate obstructive apnea adequately, and if the pressure is too high, it could interfere the sleep itself. In addition, “CPAP-related central sleep apnea (CSA)” could appear during CPAP titration.4 Due to these reasons, some patients inevitably undergo CPAP treatment with suboptimal pressure. To date, the efficacy of CPAP treatment with suboptimal pressure in OSA remains controversial. In this study, we aimed to evaluate the treatment outcome of CPAP with suboptimal pressure in OSA.