Abstract: Objective Evidence shows that CPAP therapy relying mainly on end-expiratory positive airway pressure(EEPAP)with OSAHS. Therefore, we designed expiratory positive airway pressure(EPAP)rhinobyon and made the efficacy and safety assessment. Methods Six volunteers were enrolled to measure the end-tidal carbon dioxide pressure(P_ETCO₂)while being treated by EPAP rhinobyon under different expiratory pressure. Fourteen OSAHS patients(AHI≥15/h by PSG)recruited were divided into two groups randomly and treated with CPAP and EPAP rhinobyon for a week respectively. After a week of washing out, the patients were applied with exchanged therapeutic methods for another week. The PSG was performed at the end of each week of treatment with device-on. Results There was no significant difference of P_ETCO₂ with EPAP therapies under different expiratory pressure and without any therapy(F=1.162, P=0.34). Among the 14 OSAHS patients in both groups, AHI decreased, minimum SaO₂ and mean SaO₂ increased significantly after treatment(P<0.001, respectively). There was no significant difference of the efficacy between EPAP rhinobyon and CPAP therapy(P=0.830, 0672, 0.649; P=0.473, 0.636, 0.667). Conclusion EPAP rhinobyon therapy was safe and reliable with significant efficacy for selected OSAHS patients. It could be promoted as the substitutive therapy for OSAHS in the future.

Key words: CPAP, P_ETCO₂, Sleep apnea, obstructive, AHI, SaO₂, Expiratory positive airway pressure rhinobyon