Novel grading system for quantifying upper-airway obstruction on sleep endoscopy.

ABSTRACT

BACKGROUND: The aim of this study was to present a novel anatomically comprehensive and clinically applicable system for the quantification of sleep endoscopy findings in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS). METHODS: Fifty-five adult patients with a polysomnographic diagnosis of OSAHS were referred for midazolam-induced sleep endoscopy following failure of continuous positive airway pressure. Five anatomical sites of possible obstruction along the upper airway were documented nose/nasopharynx (N), uvulopalatine plane (P), tongue base (T), larynx (L), and hypopharynx (H). Each involved site was assigned a severity grade of 1 (partial obstruction) or 2 (complete obstruction). The digits representing the obstruction pattern at each level were then added to yield a severity index (SI). The SI for each patient was determined by two independent observers. Findings were correlated with the respiratory disturbance index (RDI) and body mass index (BMI). RESULTS: The SI was significantly correlated with the RDI (R=0.746, Pearson; P<0.0001) and predicted disease severity with 65% accuracy. There was no association with BMI. By site, the tongue base and hypopharynx were significantly correlated with obstruction severity; obstruction in the tongue base predicted disease severity with a sensitivity of 68.8 and sensitivity of 81.1. CONCLUSION: Our easy-to-use endoscopic grading system provides physicians with an accurate picture of the pattern of the upper-airway system obstruction in patients with obstructive sleep apnea/hypopnea syndrome. It is a promising tool for estimating the location and severity of upper airway disease and may have implications for treatment planning.