CPAP combined with oral appliance therapy reduces CPAP requirements and pharyngeal pressure swings in obstructive sleep apnea.

STUDY OBJECTIVES Oral appliance (OA) therapy is the leading alternative to continuous positive airway pressure (CPAP) for obstructive sleep apnea (OSA). It is well tolerated compared to CPAP. However, ≥50% of patients using OA therapy have incomplete resolution of their OSA. Combination therapy with CPAP and oral appliance (CPAP+OA) is a potential alternative for incomplete responders to OA therapy. This study aimed to determine the extent to which combination therapy reduces therapeutic CPAP requirements using gold standard physiological methodology in those who have an incomplete response to OA therapy alone. METHODS 16 incomplete responders (residual AHI> 10events/h) to a novel OA with a built-in oral airway were recruited (3F:13M, aged 31-65 years, BMI: 22-38kg/m2, residual AHI range 13-63events/h). Participants were fitted with a nasal mask, pneumotachograph, epiglottic pressure catheter and standard polysomnography equipment. CPAP titrations were performed during NREM supine sleep in each participant during 3 conditions (order randomized): 1) CPAP only, 2) CPAP+OA(oral airway open), and 3) CPAP+OA(oral airway closed). RESULTS OSA was resolved at pressures of 4±2 and 5±2cmH2O during CPAP+OA (oral airway open) and CPAP+OA (oral airway closed) conditions versus 8±2cmH2O during CPAP only (P<0.01). Negative epiglottic pressure swings in oral airway open and closed conditions were normalized to CPAP only levels (-2.5[-3.7,-2.6] vs. -2.3[-3.2,-2.4]vs. -2.1[-2.7,-2.3]cmH2O). CONCLUSIONS Combined CPAP and OA therapy reduces therapeutic CPAP requirements by 35-45% and minimizes epiglottic pressure swings. This combination may be a therapeutic alternative for patients with incomplete responses to OA therapy alone and those who cannot tolerate high CPAP levels.