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

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).

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).

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.

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.