A Pilot Evaluation of a Nasal Expiratory Resistance Device for the Treatment of Obstructive Sleep Apnea

Abstract

Obstructive sleep apnea (OSA) is a major problem in need of new treatment approaches. The present pilot study tests the hypothesis that the application of expiratory resistance via a nasal valve device would improve breathing during sleep in subjects with OSA and in primary snorers. Thirty men and women were recruited from the community and from the Stanford University Sleep Disorders Clinic. Twenty-four had at least mild OSA (AHI >5), and 6 were primary snorers. Subjects underwent 2 nights of polysomnographic evaluation, one with and one without a new nasal resistance device with the order of nights counterbalanced across participants. The device consisted of a small valve inserted into each nostril calibrated to provide negligible inspiratory resistance, but increased expiratory resistance with a back pressure between 60 and 90 cm H2O*sec/Liter (at 100 mL/sec flow). Standard polysomnography was conducted to compare participants' sleep both with and without the device, with the scoring conducted blind to treatment condition. The apnea-hypopnea (AHI) (p < 0.001) and oxygen desaturation (O2DI) (p < 0.01) indices both significantly decreased, and the percentage of the night spent above 90% saturation (p < 0.05) significantly increased with device use. The observed amount of snoring (p < 0.001) was significantly decreased with device use, and there were no significant changes in measures of sleep architecture. The results of this pilot study are suggestive of a therapeutic effect of expiratory nasal resistance for some OSA patients and indicate that this technique is worthy of further clinical study.