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

Objective: 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.

Methods: 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.

Results: 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).

Conclusions: 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.