1311 Novel CPAP and Inspire Titration Sleep Study Approach - Is Two Better Than One?

Abstract Introduction Obstructive sleep apnea (OSA) is commonly treated with continuous positive airway pressure (CPAP) as first-line therapy, while hypoglossal nerve stimulation (Inspire) therapy serves as an alternative for patients intolerant of CPAP. This case report describes a novel comparative titration sleep study approach evaluating three treatment parameters in a single patient with OSA. Report of case(s) A 72-year-old patient with severe OSA (baseline AHI 45.4 events/hr) with positional component, obesity (BMI 30 kg/m2), nocturnal hypoxia on nighttime supplemental oxygen (nocturnal oxygen saturation 82%), anxiety on clonazepam, dream enactment behavior, and CPAP intolerance. Drug-induced sleep endoscopy showed only anterior and posterior pharyngeal collapse and Inspire device implantation was completed afterwards. Subsequent repeat diagnostic polysomnogram showed persistent severe OSA with concern for persistent nocturnal hypoxia. To identify therapeutic CPAP and Inspire setting parameters, an advanced titration sleep study was ordered under three conditions: Inspire monotherapy, combined Inspire with CPAP therapy, and CPAP monotherapy. Apnea-hypopnea index (AHI) served as the primary outcome measure for comparing treatment efficacy across modalities and oxygen saturation serving as a secondary outcome measure. Conclusion CPAP monotherapy demonstrated superior AHI reduction compared to both Inspire therapy alone and the combination of Inspire with CPAP therapies. Oxygenation and respiratory events improved on CPAP therapy (at 12 cm H2O, AHI 9.6 events/hr and nocturnal oxygen saturation 89%). No therapeutic setting involving Inspire therapy was found to improve AHI as well as CPAP therapy despite changing electrode configurations, pulse width/frequency and voltage parameters. AHI was most reduced when hypoglossal nerve stimulator was off, consistent with established literature showing CPAP's effectiveness in reducing AHI in moderate-to-severe OSA. CPAP therapy, which delivers positive end-expiratory pressure (PEEP), alleviates OSA by maintaining positive pharyngeal pressure transmural pressure, thereby reducing AHI by preventing the repetitive upper airway collapse that characterizes the condition. When CPAP already maintains airway patency effectively, adding Inspire may provide no additional benefit. The combined therapy approach warrants further investigation to determine if specific patient populations might benefit from dual modality treatment. The medical literature does not report any studies specifically evaluating the combination of Inspire and CPAP therapies as a parameter of an overnight in-lab titration sleep study. Support (if any)