Acoustic Pharyngometry: A Substitute for Drug-Induced Sleep Endoscopy?

Abstract

Objective: Upper airway collapse measured using supine acoustic pharyngometry at respiratory residual volume (RV) has previously been correlated with obstructive sleep apnea-hypopnea syndrome (OSAHS) severity. We aim to assess the agreement between sites of maximal upper airway obstruction measured by supine acoustic pharyngometry and drug-induced sleep-endoscopy (DISE) in snoring/OSAHS patients.

Method: In this case series, 50 consecutive patients with known snoring/OSAHS underwent in-office supine acoustic pharyngometry and DISE. Pharyngometric measurements at respiratory tidal volume were compared against the standard normal curve to establish airway landmarks. Sites of minimal cross-sectional-area at respiratory RV were compared with sites of maximal obstruction identified through DISE.

Results: Fifty patients (68% male, 32% female, age 47.3 ± 13.7, mean AHI 37.0 ± 26.8) were evaluated. All endoscopic assessments were performed by a single investigator (M.F.). Regions of maximal upper airway collapse per DISE were classified as retropalatal, mixed retropalatal and retroglossal, retroglossal, mixed retroglossal and retroepiglottic, or retroepiglottic. Graphical and numerical pharyngometric data were assessed by 3 investigators with complete agreement regarding regional collapse. Agreement between sites of maximal upper airway obstruction per DISE and regions of minimal cross-sectional-area per supine pharyngometry was 89.2% (95% CI 74.5, 95.9; P < .001).

Conclusion: Acoustic pharyngometry is a completely non-invasive mode of assessment through which numerical and graphical data regarding regional upper airway collapse can be rapidly obtained. Findings demonstrate a high level of agreement with those of DISE in the pretreatment/preoperative evaluation of patients with known snoring and/or OSAHS.