1230 Management of Severe OSA with HGNS: Importance of In-Lab Sleep Studies for Accurate Assessment-bA Case Report

Abstract Introduction Continuous positive airway pressure (CPAP) therapy is gold standard treatment for obstructive sleep apnea. Compliance issues and CPAP/BPAP intolerance have paved the way for alternative interventions such as the Hypoglossal Nerve Stimulation (HGNS) device. HGNS works by directly stimulating the hypoglossal nerve in synchrony with respirations to open the airway via tongue stiffening and protrusion, ultimately preventing airway collapse during sleep.1 Report of case(s) This case report is about a 70-year-old male who has history of severe OSA with significant hypoxemia, being managed with a HGNS implant due to CPAP intolerance. Sleep study after HGNS device activation, showed adequate treatment of OSA, AHI improved to normal range, however, persistent hypoxemia (SpO2 less than 88% for 90 min) was noted. An overnight pulse oximetry study again revealed significant hypoxemia with SpO2 less than 88% for 121 minutes. A home sleep study showed ongoing moderate OSA and hypoxemia with an AHI 26.2 per hour based on 3% desaturation hypopneas and AHI 16.0 per hour based on 4% desaturation hypopneas, in association with significant hypoxemia (SpO2 less than 88% for 54 min) despite using the HGNS implant. He was tested with an in-lab sleep study for the purpose of initiation of supplemental oxygen for management of significant hypoxemia. This study showed significant improvement of AHI to normal range of 5/hour at setting of 2.7 V, and no significant hypoxemia was noted. Conclusion The case highlights a potential discrepancy in evaluating sleep apnea severity using home sleep apnea tests in patients with HGNS device. Most insurance companies approve home sleep apnea tests, but it is advised that patients with HGNS devices showing persistent significant OSA or hypoxemia on a home sleep study undergo a repeat in-lab sleep study for a more accurate estimation of sleep apnea severity and hypoxemia. Support (if any) References 1. Olson MD, Junna MR. Hypoglossal Nerve Stimulation Therapy for the Treatment of Obstructive Sleep Apnea. Neurotherapeutics. 2021 Jan;18(1):91-99. doi: 10.1007/s13311-021-01012-x. Epub 2021 Feb 8. PMID: 33559036; PMCID: PMC8116425. 2. Punjabi NM, Aurora RN, Patil SP. Home sleep testing for obstructive sleep apnea: one night is enough! Chest. 2013 Feb 1;143(2):291-294. doi: 10.1378/chest.12-2699. PMID: 23381307; PMCID: PMC3566993.