Obstructive sleep apnea: A study by simultaneous polysomnography and ultrasonic imaging

Abstract

Obstructive sleep apnea (OSA) is associated with major morbidity and daytime somnolence. 1 Location of the obstruction cannot be determined by polysomnography, thereby contributing to variance in cure rates for surgical procedures such as uvulopalatopharyngoplasty (UPPP). 2,3 There is no clinically accepted, comfortable, and noninvasive method for visualizing the airway during sleep. Ultrasonic imaging of the airway is an established method used in the evaluation of swallowing. 4,5 It is a dynamic, safe method, permitting the noninvasive visualization of soft-tissue structures of the pharynx. 5 Ultrasound has never been used in the evaluation of OSA.Methods. Five male subjects age 35 to 57 years with OSA underwent this procedure. All subjects had apnea indices greater than 35. One subject had undergone unsuccessful UPPP in the past, and all subjects were using continuous positive airway pressure (CPAP) at home.Video output from the real-time mechanical sector ultrasonic machine (ATL HDI 5000, Advanced Technology Laboratories, Bothell, WA) was combined with the polysomnography signal from a Telefactor digital EEG machine (Telefactor, West Conshohocken, PA) equipped with sleep software that produces a splitscreen image containing polysomnography and ultrasound recorded simultaneously. The ultrasonic transducer (P5-3 phased array or L12-5 linear array) was fastened around the head and positioned submentally, resting just above the sternum in a slinglike cotton pocket fastened around the neck with Velcro bands for position stabilization during sleep (figure). Time on both was synchronized. Recordings were made on an outpatient basis, when subjects had been deprived of 2 to 3 hours of sleep the night before, and lasted for approximately 1.5 to 2 hours.The polysomnogram was scored according to the methods of Rechtshaffen and Kales. 6 Obstructive events were scored only if they lasted 10 seconds or more. The first 20 apneic events were identified for each subject on the polysomnogram, and simultaneous ultrasonic images were observed. Each event identified by polysomnography was graded as containing or lacking a simultaneous ultrasonic event, and was described in terms of the locations and movements of the structures involved.Results. A total of 93 events were identified. One subject had difficulty with sleep maintenance due, in part, to OSA, and had only 13 events during the entire testing session. All apneas identified by polysomnography were accompanied by an ultrasonic event. No ultrasonic obstructive events were noted without polysomnographic events. The nature of the event seen on ultrasound was consistent for each subject and was seen on all samples. Five to 10 seconds before the onset of apnea, the geniohyoid and mylohyoid muscles composing the floor of the mouth relaxed. At the beginning of and during each subsequent apnea, the tongue base moved posterior or inferior toward the hypopharynx and cased airway obstruction, which was reflected in the polysomnograph. At the end of the apneic event, a slight contractio...

Simultaneous recording of ultrasound and polysomnography during natural sleep in patients with obstructive sleep apnea: a pilot study

“…Using a commercial ultrasound system and PSG for simultaneous recording in patients with OSA, Siegel et al . demonstrated a positive relationship between an ultrasonic event and the obstructive respiratory event, which was detected in the PSG (Siegel et al ., ). They defined the ultrasonic event as a posterior or inferior displacement of the tongue base toward the hypopharyngeal airway at the occurrence of and during each subsequent apnea.…”

“…Automatic quantification of the differences among tongue contours obtained through ultrasound imaging has been proposed as a reliable method for the analysis of tongue positions during the production of various speech patterns (Lancia et al, 2015). Using a commercial ultrasound system and PSG for simultaneous recording in patients with OSA, Siegel et al demonstrated a positive relationship between an ultrasonic event and the obstructive respiratory event, which was detected in the PSG (Siegel et al, 2000). They defined the ultrasonic event as a posterior or inferior displacement of the tongue base toward the hypopharyngeal airway at the occurrence of and during each subsequent apnea.…”

Submental Ultrasonographic Parameters among Patients with Obstructive Sleep Apnea

“…Full-night PSG (Somnologica 3.2; Embla, Denver, Colorado) was performed in the sleep center laboratory. The patients were divided into 4 groups according to the apneahypopnea index (AHI): normal and/or primary snoring (AHI \5), mild OSA (AHI = 5-15), moderate OSA (AHI = [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30], and severe OSA (AHI .30). The minimum oxygen saturation (MOS) value was recorded as a percentage.…”

Role of Ultrasound in Airway Assessment and Management

“…6 In patients with sleep apnoea, upper airway ultrasonography has been used to visualise approximation of the tongue base posteriorly and inferiorly towards the hypopharynx to cause airway obstruction. 10,11 Pharyngeal or laryngeal pathology, such as tumours, abscesses or epiglottitis which may have a significant effect during airway management, are detected by the use of US scan.…”