Available Techniques for Objective Assessment of Upper Airway Narrowing in Snoring and Sleep Apnea

Abstract

A number of techniques are available to determine the level of obstructive predominance in snoring and in the obstructive sleep apnea hypopnea syndrome (OSAHS): lateral cephalography, awake endoscopy, awake endoscopy with the Müller maneuver, endoscopy during sleep, endoscopy with nasal continuous positive airway pressure during sleep, fluoroscopy, CT scanning, MR scanning, manometry, and acoustic reflections. Data from different studies using various methods suggest that different patients have different patterns of narrowing or collapse of the pharynx. No reference standard exists for the determination of the predominant obstructive level during obstructive events, so further investigations are necessary to improve and validate existing methods and develop new techniques. These would improve our understanding of the pathophysiology of OSAHS and snoring and help to select the correct treatment option for different patients. This article lists criteria that must be used to assess the available techniques for diagnosis of obstruction level in snoring and OSAHS. The advantages and limitations of each diagnostic technique are summarized, with emphasis on the acoustic reflectometry technique.

Evaluation of cross-section airway configuration of obstructive sleep apnea

“…Our results agree with the results reported by cephalometric based studies, fluoroscopy imaging studies, as well as other CT and MR imaging studies. 7,8,11,22 In particular it correlates with data found by Cosentini et al 15 who examined 28 obese severe OSA patients with MRI imaging during wakefulness and reported that the subjects had a very small minimal cross-sectional area (35±16 mm 2 ) which was usually positioned retropalatally.…”

Clinical Application of Subjective Measurements for OSAS Assessment: Predictive Factors of Syndrome Severity

“…Ritter et al [32] in their study concluded that upper airway collapse in response to the inspiratory pressure generated during a Mueller maneuver in both retropalatal and retroglossal regions is mediated primarily through reduction in the lateral airway dimension secondary to the movement of lateral pharyngeal tissue structures. According to the literature, the advantages of Mueller’s maneuver are: easy to perform for patient and examiner, time and cost effective and broadly widespread [31,33]. The disadvantages are: minimally invasive, subjective for both patient and examiner, questionable reproducibility, possible dynamic modification of the upper airway dynamics because of the endoscope presence, which does not necessarily reproduce apnea-hypopnea episodes [21,24,32].…”

Quantification of Pharyngeal Patency in Patients with Sleep-Disordered Breathing

“…Fiberoptic nasopharyngoscopy during sleep was one of the earliest techniques to study the site of UA collapse during sleep. However, there are striking discrepancies between the fi ndings of different authors [11][12][13][14] . The exposure to radiation during both somnofl uoroscopy and cine computed tomography (CT) will limit the procedure time with these methods [11,12] .…”

“…Moreover, UA collapse can occur simultaneously at multiple sites [10] . Localization of the pharyngeal collapse in the individual SDB patient may be important to optimize the results of local therapies [9][10][11][12] . Fiberoptic nasopharyngoscopy during sleep was one of the earliest techniques to study the site of UA collapse during sleep.…”

“…Whereas the site of UA collapse has been reported to vary, localization of the site of collapse is considered essential for proper treatment [9,10] . Therefore, a variety of techniques has recently been developed to determine the site of UA collapse [11,12] . However, most of these techniques lack quantifi cation of the degree of pharyngeal closure.…”