Effects of mouth opening on upper airway collapsibility in normal sleeping subjects.

Study Objectives: Oronasal masks are frequently used for continuous positive airway pressure (CPAP) treatment in patients with obstructive sleep apnea (OSA). The aim of this study was to (1) determine if CPAP requirements are higher for oronasal masks compared to nasal mask interfaces and (2) assess whether polysomnography and patient characteristics differed among mask preference groups. Methods: Retrospective analysis of all CPAP implementation polysomnograms between July 2013 and June 2014. Prescribed CPAP level, polysomnography results and patient data were compared according to mask type (n = 358). Results: Oronasal masks were used in 46%, nasal masks in 35% and nasal pillow masks in 19%. There was no difference according to mask type for baseline apnea-hypopnea index (AHI), body mass index (BMI), waist or neck circumference. CPAP level was higher for oronasal masks, 12 (10-15.5) cm H 2 O compared to nasal pillow masks, 11 (8-12.5) cm H 2 O and nasal masks, 10 (8-12) cm H 2 O, p < 0.0001 (Median [interquartile range]). Oronasal mask type, AHI, age, and BMI were independent predictors of a higher CPAP pressure (p < 0.0005, adjusted R 2 = 0.26.). For patients with CPAP ≥ 15 cm H 2 O, there was an odds ratio of 4.5 (95% CI 2.5-8.0) for having an oronasal compared to a nasal or nasal pillow mask. Residual median AHI was higher for oronasal masks (11.3 events/h) than for nasal masks (6.4 events/h) and nasal pillows (6.7 events/h), p < 0.001. Conclusions: Compared to nasal mask types, oronasal masks are associated with higher CPAP pressures (particularly pressures ≥ 15 cm H 2 O) and a higher residual AHI. Further evaluation with a randomized control trial is required to definitively establish the effect of mask type on pressure requirements. Keywords: obstructive sleep apnea, CPAP, treatment, mask, nasal pillows, nasal mask, oronasal mask Commentary: A commentary on this article appears in this issue on page 1209. Citation: Deshpande S, Joosten S, Turton A, Edwards BA, Landry S, Mansfield DR, Hamilton GS. Oronasal masks require a higher pressure than nasal and nasal pillow masks for the treatment of obstructive sleep apnea. J Clin Sleep Med 2016;12(9):1263-1268. I NTRO DUCTI O NObstructive sleep apnea (OSA) is characterized by excessive daytime sleepiness due to recurrent episodes of partial (hypopnea) or complete (apnea) obstruction of the upper airway during sleep. OSA is highly prevalent and moderate-severe OSA is reported to affect 17% of men and 9% of women older than 50 years.1 Untreated OSA is associated with significant morbidity and mortality, with increased risk of hypertension, depression, motor vehicle accidents, cardiovascular disease, and premature death.2-5 The mainstay of therapy for OSA is nocturnal continuous positive airway pressure (CPAP), which prevents collapse by pneumatically splinting the upper airway. CPAP has been shown to reduce daytime somnolence, improve quality of life, and improve nocturnal oxygen saturation. 6 CPAP has also been shown to reduce blood pressure, and in severe OSA, c...

Section: Discussionmentioning

confidence: 99%

Oronasal Masks Require a Higher Pressure than Nasal and Nasal Pillow Masks for the Treatment of Obstructive Sleep Apnea

Deshpande

Joosten

Turton

et al. 2016

“…Mouth opening has been shown to increase upper airway collapsibility. 35 In contrast to previous reports, in our study NEP was applied through a nasal mask in the supine position. Our method therefore may convey more relevant information for patients under investigation for OSA.…”

Section: Discussionmentioning

confidence: 82%

Upper Airway Collapsibility Assessed by Negative Expiratory Pressure while Awake is Associated with Upper Airway Anatomy

Hirata

Schorr

Kayamori

et al. 2016

Study Objectives:There is a growing interest to develop a simple method to characterize the mechanisms leading to upper airway collapse in order to guide treatment options in patients with obstructive sleep apnea (OSA). Critical closing pressure (Pcrit) during sleep is able to predict the anatomical component of OSA. However, Pcrit is a laborious method that is only used for research purposes. The application of negative expiratory pressure (NEP) is a simple method to assess upper airway collapsibility that can be easily performed during wakefulness. We hypothesized that NEP will be, similarly to Pcrit, associated with upper airway anatomy assessed by computed tomography (CT) scan. Methods: Patients under investigation for OSA underwent polysomnography, CT of the upper airway, NEP while awake, and Pcrit during sleep. NEP was performed with −5 cm H 2 O in supine position using a nasal mask. Pcrit was measured during sleep induced by low doses of midazolam. Results: Twenty-eight male subjects were studied (age 45 ± 13 y, body mass index 29.4 ± 4.9 kg/m 2 , apnea-hypopnea index (AHI) 30 ± 26, range 2 to 86 events/h). NEP and Pcrit were similarly associated with tongue area (r = 0.646 and r = 0.585), tongue volume (r = 0.565 and r = 0.613) and pharyngeal length (r = 0.580 and r = 0.611), respectively (p < 0.05 for all comparisons). NEP and Pcrit were also significantly correlated with AHI (r = 0.490 and r = 0.531). NEP and Pcrit were significantly higher in patients with severe OSA than the remaining population. Conclusions: NEP is a simple and promising method that is associated with the anatomical component of upper airway collapsibility. NEP may be valuable to select patients for noncontinuous positive airway pressure alternative therapies for OSA.

“…1 It has been reported that upper airway collapsibility and resistance during sleep were significantly higher in subjects who were breathing through the mouth than in those who were breathing through the nose, which is different from that seen during the conscious state. 2,3 Other reasons for nasal breathing over mouth breathing during normal sleep are based on the physiological effects of decreased nasal airflow. First, bypassing the nasal airway can lead to reduced nasal receptor activation, deactivation of the nasal ventilatory reflex, and reduced spontaneous ventilation.…”

Section: Of Patterns the Nasal Airway And Sdbmentioning

confidence: 99%

“…Mouth opening increased upper airway collapsibility during sleep, which is different from that seen when awake. 2 Fitzpatrick et al 3 confi rmed that during sleep, upper airway resistance during oral breathing was 2.5 times higher than that during nasal breathing. Mouth opening may be associated with narrowing of the pharyngeal lumen and decreases in the retroglossal diameter.…”

mentioning

confidence: 99%

Relationship between Oral Flow Patterns, Nasal Obstruction, and Respiratory Events during Sleep

Suzuki

Furukawa

Sugimoto

et al. 2015

We conducted an observational cross-sectional study of 85 Japanese adult patients examined by our sleep laboratory for Study Objectives: Sleep breathing patterns are altered by nasal obstruction and respiratory events. This study aimed to describe the relationships between specifi c sleep oral fl ow (OF) patterns, nasal airway obstruction, and respiratory events. Methods: Nasal fl ow and OF were measured simultaneously by polysomnography in 85 adults during sleep. OF was measured 2 cm in front of the lips using a pressure sensor. Results: OF could be classifi ed into three patterns: postrespiratory event OF (postevent OF), during-respiratory event OF (during-event OF), and spontaneous arousal-related OF (SpAr-related OF). Postevent OFs begin at the end of airfl ow reduction, are preceded by respiratory arousal, and are accompanied by postapneic hyperventilation; duringevent OFs occur during nasal fl ow reduction; and SpAr-related OFs to OF begin during stable breathing, and are preceded by spontaneous arousal but are rarely accompanied by apnea/hypopnea. Multivariate regression showed that nasal obstruction was predictive of SpAr-related OF. The relative frequency of SpAr-related OF events was negatively correlated with the apnea-hypopnea index. The fraction of SpAr-related OF duration relative to total OF duration was signifi cantly greater in patients with nasal obstruction than in those without. Conclusions: SpAr-related OF was associated with nasal obstruction, but not respiratory events. This pattern thus functions as a "nasal obstruction bypass", mainly in normal subjects and patients with mild sleep disordered breathing (SDB). By contrast, the other two types were related to respiratory events and were typical patterns seen in patients with moderate and severe SDB. 1 showed that oral breathing during sleep is induced by increased nasal resistance. Mouth opening increased upper airway collapsibility during sleep, which is different from that seen when awake.2 Fitzpatrick et al. 3 confi rmed that during sleep, upper airway resistance during oral breathing was 2.5 times higher than that during nasal breathing. Mouth opening may be associated with narrowing of the pharyngeal lumen and decreases in the retroglossal diameter. Mouth opening and oral breathing may, but not necessarily, lead to hypopnea or apnea. However, Lavie et al. 4 showed that nasal obstruction caused a signifi cant increase in the number of arousals during sleep in patients with nonapneic breathing disorders. In another recent study, Hsia et al.5 described a snoring pattern during nasal breathing in patients with nasal obstruction that was alleviated with oral breathing.Against this background, we hypothesized that different kinds of oral fl ow (OF) patterns exist during sleep and are associated with distinct sleep related respiratory events. The BRIEF SUMMARYCurrent Knowledge/Study Rationale: The relationship between oral fl ow (OF) patterns, nasal obstruction, and obstructive respiratory events is unclear. We hypothesized that specifi c O...