The impact of nasal mask versus oronasal mask CPAP treatment on the site of collapse and the differences in physiologic state.

PURPOSE: The type of mask, either oronasal or nasal, is known to influence the efficacy of Continuous Positive Airway Pressure (CPAP) therapy. Previous studies have examined mask effects on either anatomical airway changes or clinical outcomes, but none have simultaneously assessed anatomical and physiological impacts within the same patients. To our knowledge, this study is the first randomized crossover trial to investigate how mask type influences both airway collapse and oxygenation across CPAP pressure levels.

METHODS

We conducted a prospective randomized controlled crossover trial including 30 adults with obstructive sleep apnea (OSA) confirmed by polysomnography. Each patient underwent drug-induced sleep endoscopy (DISE) while receiving CPAP with both nasal and oronasal masks in random order. Airway obstruction was evaluated using the VOTE classification, pharyngeal opening pressures (PhOP) were measured, and oxygen saturation (SpO₂) was monitored across CPAP levels.

RESULTS

A total of 27 patients were included in the final analysis (mean age 54.3 ± 15.2 years; median AHI 29.6 [IQR: 10.6-53.9]/h). Compared with oronasal masks, nasal masks more effectively relieved obstruction at the velum, oropharynx, and tongue base at therapeutic pressures and required significantly lower PhOP values at the velum and tongue base. Moreover, nasal masks maintained higher SpO2 within the therapeutic range (6-12 cmH2O).

CONCLUSION

Nasal masks were more effective than oronasal masks in reducing airway obstruction and maintaining oxygenation during CPAP therapy, suggesting anatomical and physiological advantages that may guide personalized mask selection in OSA management.