[Comparison of diagnosis and localization methods in obstructive sleep apnea syndrome: apneagraph vs polysomnography...

ApneaGragh is a new device for simultaneous determination of obstructive sleep apnoeic events and continuous pressure measurements for localization of upper airway obstructive site. This study is to evaluate the clinical value of it.

From April to October in 2006, 32 obstructive sleep apnea (OSA) patients diagnosed by polysomnography (PSG) were examined by two methods: Endoscopy with müller's maneuver at daytime and continuous upper airway pressure recording with ApneaGraph at night in Peking Union Medical College Hospital. The upper airway obstructive sites determined by the two methods were compared. ApneaGraph transducer catheter contains two pressure sensors and two temperature sensors used for obstruction site determination and detection of apnoeic events during sleep. Obstructive sites were divided into upper (retropalatal oropharynx) or lower level (retroglossal region). The lower limit of upper airway obstruction was determined by observed pressure pattern. Used constituent retio to reflect the obstructive proportion of different levels. The apnea hypopnea index (AHI) measured by PSG and ApneaGraph were also compared.

Two patterns of obstruction were observed in our group: 1. The site of obstruction was located only at the upper level. 2. The obstruction of upper and lower level all present. Site of obstruction determined by Apneagraph: 28 (87.5%) cases had predominant sites of obstructions in upper level (the constituent retio of retropalatal obstruction > 50%), the others in lower level (the constituent retio of retroglossal obstruction > 50%). Endoscopy localization of obstruction: 18 cases had retropalatal obstructions alone, 13 cases had obstructions of retropalate combined with retroglossa, only 1 patient didn't have obstruction. Defined the constituent retio higher than thirty percent the criteria of obstruction, then identical results were obtained by both methods in retropalatal segment in 27 (84.4%) of the patients, while in only 17 (53.1%) obstructions was determined by the both methods in retroglossal areas. The polysomnograpic AHI (x +/- s) was 52.2 +/- 18.1, versus 50.2 +/- 16.0 obtained by ApneaGraph. There was a significant correlation between them (r = 0.876, P < 0.001).

ApneaGraph can identify the level of upper airway obstruction more accurate than fiberoptic pharyngoscopy. In the meantime, it also can serve as a portable PSG to diagnose sleep disordered breathing qualitatively.