Nasal versus oronasal mask in patients under auto-adjusting continuous positive airway pressure titration: a real-life study

Mask type (nasal versus oronasal) can affect the optimal pressure required to correct the apnea/hypopnea index (AHI) in obstructive sleep apnea (OSA) subjects treated with CPAP. Our objective was to evaluate if mask type influenced CPAP titration outcomes in OSA patients. A retrospective study of individuals with a baseline AHI ≥ 15.0/h, who received an auto-adjusting CPAP titrating device (S9 AutoSet ResMed®) in a sleep-lab setting. The mask type oronasal (OM) or nasal (NM) was always selected by the patients. Optimal pressure requirements, leak, and residual AHI were compared based on mask type. Overall, 436 patients were included: 283 with NM (64.9%) and 153 with OM (35.1%). At baseline, NM and OM cohorts had similar AHI (p = 0.160). Patients allocated to the OM cohort had a higher 95th percentile pressure, a higher 95th percentile leak, and a higher residual AHI than those with a NM: pressure requirement: 12.9 cm H2O (IQR: 10.6–15.0) versus 10.7 cm H2O (IQR: 9.2–12.3); leak: 21.6 L/min (IQR: 9.6–37.2) versus 9.6 L/min (IQR: 3.6–19.2); and residual AHI: 4.9/h (IQR: 2.4–10.2) versus 2.2/h (IQR: 1.0–4.4), respectively (p < 0.001 for all). CPAP mask type based on individual preferences exerts profound effects on optimal CPAP pressures and efficacy. Patients titrated with OM showed higher pressure requirements, had higher a leak, and higher residual AHI when compared to NM, which may adversely impact treatment adherence and other health outcomes.