0531 Identifying Airway Collapse Patterns in OSA Using Nasal Pressure Signal as a Surrogate for Airflow Shape

Abstract Introduction Identification of the site(s) and characteristics of upper airway collapse is important for treatment selection and optimization in patients with obstructive sleep apnea (OSA) for whom an alternative to PAP therapy is indicated. The most widely accepted approach to reliably evaluate the location and severity of upper airway collapse is through drug-induced sleep endoscopy (DISE). Analysis of airflow shapes has emerged as a potential future alternative to DISE. Specifically, prior investigations have identified associations between the contours of objective airflow measurements and DISE findings from simultaneous endoscopy. Since objective airflow measurements are not obtained during standard polysomnography, this study sought to evaluate for associations between DISE findings and nasal pressure measurements as a surrogate for airflow. Methods Nasal pressure measurements were obtained using a type III home sleep testing device during DISE for patients at a single institution as part of their workups for non-PAP therapy. Nasal pressure data were synchronized to endoscopic video recordings, and segments of airflow waveforms corresponding to specific DISE findings were visually screened. Results Twenty four adult study subjects with OSA were ultimately included in this investigation. Only a subset of previously-described airflow shape correlations were found to retain associations to DISE findings. Four airflow shape surrogates were found to consistently correlate with specific DISE findings. Findings that relied on flow amplitude were not able to be detected using other nasal pressure signal characteristics. Conclusion Nasal pressure signal shape has potential as a limited surrogate for airflow shape, and in this investigation it was found to retain associations to upper airway collapse patterns obtained via DISE in patients with OSA . Support (if any)