The role of the expiratory phase in obstructive sleep apnoea

Abstract

The role of the expiratory phase in obstructive sleep apnoea (OSA) is not well known. The aim of our study was to verify the contribution of expiratory narrowing to apnoea in a group of OSA patients by evaluating the effects of short-term treatment with continuous positive airway pressure (CPAP), intermittent positive pressure ventilation (IPPV) and bi-level positive airway pressure (BIPAP). We studied a selected group of 10 OSA patients whose therapeutic pressure level of CPAP was at least 10 cm H2O. During CPAP therapy the mean apnoea/hypopnoea index (AHI) and oxyhaemoglobin desaturation index (ODI) decreased from 64.8 to 6.3 (P < 0.001) and from 58.5 to 6.1 (P < 0.001), respectively and mean nadir SAO2 increased from 62.0 to 91.6 (P < 0.001). None of the patients reached optimal setting (elimination of snoring, reduction of apnoeas and non-apnoeic desaturation events at least to 15 or less per hour of sleep and maintenance of oxygen saturation approximately 90%) during IPPV and two patients did not tolerate final IPAP pressure levels. When a critical level of EPAP (BIPAP) was applied in the same night to these patients, optimal setting was reached in all subjects. During BIPAP, mean AHI decreased from 64.8 to 7.4 (P < 0.001); ODI decreased from 58.5 to 7.6 (P < 0.001) and nadir SAO2 increased from 62.0 to 91.2 (P < 0.001). Our study confirms the essential role of a critical level of EPAP in successful ventilatory treatment in OSA, thereby indicating, in agreement with few previous studies, the critical role of end of expiratory occlusion in OSA pathogenesis.

Retrospective, nonrandomized controlled study on autoadjusting, dual-pressure positive airway pressure therapy for a consecutive series of complex insomnia disorder patients

“…A distinctive observation in this ASV study pinpointed the ubiquitous inability of chronic insomnia disorder patients with comorbid OSA/UARS to adapt to standard PAP devices, such as continuous positive airway pressure (CPAP), continuous positive airway pressure with expiratory pressure relief (CFLEX), automatic continuous positive airway pressure (APAP), and Bilevel positive airway pressure (BPAP) due to self-reported discomfort and intolerance triggered by the vaguely defined phenomenon of expiratory pressure intolerance (EPI)41,42 even among those using PAP devices with basic expiratory pressure relief (EPR) systems 39. These adverse effects resolved with ASV use,43 and in our clinical experience, many insomnia patients also adapt well to autobilevel PAP (ABPAP) devices 43,44.…”

Detection of breathing sounds during sleep using non-contact audio recordings

“…Distinguishing between inspiratory and expiratory sound events will allow better estimation of breathing patterns. Moreover, several studies have found that expiratory events may hold hidden information for SDB diagnosis [9][10][11]. Thus, by using the additional expiratory information, SDB diagnosis and sleep quality assessment can be improved [12,13].…”

Transoral Radiofrequency Treatment of Snoring

“…Forty million people nationwide are diagnosed with a sleep disorder; the most serious is obstructive sleep apnea (OSA). It is estimated that 10% to 15% of the population is affected by OSA 1–3 …”

“…It is estimated that 10% to 15% of the population is affected by OSA. [1][2][3] The most common complaint is snoring. This symptom is not of frivolous importance.…”