(045) Are we missing sleep apnea in patients with subglottic stenosis?

Introduction: Subglottic stenosis (SGS) is a narrowing of the subglottic airway with an impact on daytime dyspnea and reduced peak expiratory flow (PEF). The aim of this study is to characterize the prevalence of obstructive sleep apnea (OSA). We hypothesize a reduced airflow at night with a greater predisposition to OSA and hypoxemia in this population.

Methods: A prospective cohort study was conducted on adult subjects at a tertiary academic medical center from 2022-2023. Subjects with a recent airway dilation ( < 3 months), tracheostomy, prior diagnosis of OSA, posterior glottic stenosis, and/or vocal fold paralysis were excluded from enrollment. Demographic data was collected. All subjects completed a PEF measurement and one-night home sleep test (HST). HSTs were scored by a board-certified sleep medicine physician and total recording time (TRT), obstructive apnea-hypopnea index (OAHI), central apnea index (CAI) Oxygen (O2) nadir, and time O2 < 89% were collected. OSA severity was categorized into none (OAHI < 5), mild (OAHI >=5 & < 15), moderate (OAHI>=15 & < 30), and severe (OAHI >=30). Descriptive statistics with 25% and 75% quartiles and correlation between AHI and PEF controlling for BMI were performed.

Results: Twenty subjects participated in the study; all were Caucasian females with a median age of 49 (41, 55) years and a BMI of 24.6 (21.8, 26.6). The majority (N=18, 80%) presented with idiopathic SGS, and a median PEF of 290 (236, 346). All studies had more than 6 hours of recording time with OSA present in 43% of subjects. Severity in subjects with OSA was categorized into 67% mild, 33% severe, and none with severe OSA. Central apneas were minimal with a median CAI of 0.05 (0, 0.3). Median O2 nadir was 84.5% (80, 87) with median hypoxemia (time O2 < 89%) of 2% (0,13). PEF did not correlate to AHI, adjusting for BMI (p>0.05).

Conclusions: Reduced nighttime airflow is present within a small cohort of patients with SGS demonstrating an elevated prevalence of OSA. Further study of airway dilation’s impact on airflow and associated threshold to prevent OSA is necessary to prevent the long-term consequences of untreated OSA.