Airway Dilator Muscle Activity and Lung Volume During Stable Breathing in Obstructive Sleep Apnea

Jordan, Amy S.; White, David P.; Lo, Yu‐Lun; Wellman, Andrew; Eckert, Danny J.; Yim-Yeh, Susie; Eikermann, Matthias; Smith, Scott A.; Stevenson, Karen; Malhotra, Atul

doi:10.1093/sleep/32.3.361

Cited by 148 publications

(114 citation statements)

References 31 publications

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“…We therefore propose that on arousal there is preferential or more prolonged activation of both inspiratory and expiratory (tonic) component of upper airway dilator muscles, such that either the critical ratio of dilator to pump muscle activity is maintained despite a period of relative hypocapnia, or that expiratory airway collapse is prevented. Consistent with this idea, our own prior study of naturally occurring respiratory events in OSA patients also showed marked dilator muscle activation at the termination of respiratory events with arousal and no subsequent period of reduced activity during the next event (28). In fact, dilator muscle activity often ramped up over the course of respiratory events (see Figure 4 in Reference 28) as did the negative epiglottic pressure swings raising doubt over whether the hyperventilation at arousal was truly excessive (reduced CO 2 or respiratory drive below the level present on the initial event).…”

Section: Do Arousals Predispose To Further Obstructive Events?supporting

confidence: 69%

Termination of Respiratory Events with and without Cortical Arousal in Obstructive Sleep Apnea

Jordan

Eckert²,

Wellman³

et al. 2011

Am J Respir Crit Care Med

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Rationale: A total of 20-30% of respiratory events in obstructive sleep apnea are terminated without clear arousal. Arousals are thought to predispose to further events by promoting hyperventilation, hypocapnia, and upper-airway dilator muscle hypotonia. Therefore, events terminated without arousal may promote stable breathing. Objectives: To compare physiologic changes at respiratory event termination with American Sleep Disorders Association (ASDA) Arousal to No Arousal, and determine whether secondary respiratory events are less common and have higher dilator muscle activity after No Arousal compared with ASDA Arousal. Methods: Patients with obstructive sleep apnea wore sleep staging, genioglossus (EMG GG ), and tensor palatini (EMG TP ) electrodes plus a nasal mask and pneumotachograph. During stable sleep, continuous positive airway pressure (CPAP) was lowered for 3-minute periods to induce respiratory events. Physiologic variables were compared between events terminated with (1) ASDA Arousal, (2) No Arousal, or (3) sudden CPAP increase (CPAPinc, control). Measurements and Main Results: Sixteen subjects had adequate data. EMG GG , EMG TP , and heart rate increased after ASDA Arousal (340 6 57%, 215 6 28%, and 110.7 6 2.3%) and No Arousal (185 6 32%, 167 6 15%, and 108.5 6 1.6%) but not CPAPinc (90 6 10%, 94 6 11%, and 102.1 6 1%). Ventilation increased more after ASDA Arousal than No Arousal and CPAPinc, but not after accounting for the severity of respiratory event. Fewer No Arousals were followed by secondary events than ASDA Arousals. However, low dilator muscle activity did not occur after ASDA Arousal or No Arousal (EMG GG rose from 75 6 5 to 125 6 7%) and secondary events were less severe than initial events (ventilation rose 4 6 0.4 to 5.5 6 0.51 L/min). Conclusions: Respiratory events that were terminated with ASDA Arousal were more severely flow-limited, had enhanced hyperventilation after event termination, and were more often followed by secondary events than No arousal. However, secondary events were not associated with low dilator muscle activity and airflow was improved after both No Arousal and ASDA Arousal.Keywords: pharyngeal muscle activity; upper airway obstruction; genioglossus; tensor palatini; obstructive respiratory event Approximately 20-30% of respiratory events in obstructive sleep apnea (OSA) do not end with clear arousal from sleep (1-4). Whether subcriterion arousals are present or not has been debated in the literature and is not yet resolved (1, 2, 4, 5). However, the presence of cortical arousal results in enhanced hyperventilation on termination of respiratory events (4). This greater hyperventilation is expected to result in hypocapnia and dilator muscle hypotonia on the return to sleep (because dilator muscle activity, and presumably muscle tone, varies proportionately with respiratory drive), predisposing to further airway obstruction. However, whether dilator muscle activity is reduced in this setting has not been assessed.The concept that arousal-induced hyperventilatio...

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Section: Do Arousals Predispose To Further Obstructive Events?supporting

confidence: 69%

Termination of Respiratory Events with and without Cortical Arousal in Obstructive Sleep Apnea

Jordan

Eckert²,

Wellman³

et al. 2011

Am J Respir Crit Care Med

Self Cite

View full text Add to dashboard Cite

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“…During respiratory events in REM sleep, the tonic activity of the GGM is reduced even below the level during respiratory events in non-REM sleep phase 2. However, some subjects, despite activating their GGM, are not able to stabilise their breathing during sleep [59].…”

Section: Non-anatomical Traitsmentioning

confidence: 99%

Personalised medicine in sleep respiratory disorders: focus on obstructive sleep apnoea diagnosis and treatment

et al. 2017

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In all fields of medicine, major efforts are currently dedicated to improve the clinical, physiological and therapeutic understanding of disease, and obstructive sleep apnoea (OSA) is no exception. The personalised medicine approach is relevant for OSA, given its complex pathophysiology and variable clinical presentation, the interactions with comorbid conditions and its possible contribution to poor outcomes. Treatment with continuous positive airway pressure (CPAP) is effective, but CPAP is poorly tolerated or not accepted in a considerable proportion of OSA patients. This review summarises the available studies on the physiological phenotypes of upper airway response to obstruction during sleep, and the clinical presentations of OSA ( phenotypes and clusters) with a special focus on our changing attitudes towards approaches to treatment. Such major efforts are likely to change and expand treatment options for OSA beyond the most common current choices (i.e. CPAP, mandibular advancement devices, positional treatment, lifestyle changes or upper airway surgery). More importantly, treatment for OSA may become more effective, being tailored to each patient's need.

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“…10 Second, a brisk ventilatory response can occur with arousal, which could perpetuate fluctuations in CO 2 and lead to respiratory control instability. 5,6,11,12 Lastly, periods of breathing stability during sleep, mediated by an increase in the arousal threshold and increased pharyngeal dilator muscle activation, 13,14 occur intermittently in most patients with OSA. 4 Thus, waking up prematurely to a relatively modest level of airway narrowing can limit the ability to build up sufficient respiratory stimuli to recruit the pharyngeal dilator muscles to open the upper airway, thereby achieving breathing stability.…”

Section: Introductionmentioning

confidence: 99%

Trazodone Increases the Respiratory Arousal Threshold in Patients with Obstructive Sleep Apnea and a Low Arousal Threshold

Eckert

Malhotra

Wellman

et al. 2014

Sleep

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122

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Study Objectives: The effect of common sedatives on upper airway physiology and breathing during sleep in obstructive sleep apnea (OSA) has been minimally studied. Conceptually, certain sedatives may worsen OSA in some patients. However, sleep and breathing could improve with certain sedatives in patients with OSA with a low respiratory arousal threshold. This study aimed to test the hypothesis that trazodone increases the respiratory arousal threshold in patients with OSA and a low arousal threshold. Secondary aims were to examine the effects of trazodone on upper airway dilator muscle activity, upper airway collapsibility, and breathing during sleep. Design: Patients were studied on 4 separate nights according to a within-subjects cross-over design. Setting: Sleep physiology laboratory. Patients: Seven patients with OSA and a low respiratory arousal threshold. Interventions: In-laboratory polysomnograms were obtained at baseline and after 100 mg of trazodone was administered, followed by detailed overnight physiology experiments under the same conditions. During physiology studies, continuous positive airway pressure was transiently lowered to measure arousal threshold (negative epiglottic pressure prior to arousal), dilator muscle activity (genioglossus and tensor palatini), and upper airway collapsibility (Pcrit). Measurements and Results:Trazodone increased the respiratory arousal threshold by 32 ± 6% (-11.5 ± 1.4 versus -15.3 ± 2.2 cmH 2 O, P < 0.01) but did not alter the apnea-hypopnea index (39 ± 12 versus 39 ± 11 events/h sleep, P = 0.94). Dilator muscle activity and Pcrit also did not systematically change with trazodone. Conclusions: Trazodone increases the respiratory arousal threshold in patients with obstructive sleep apnea and a low arousal threshold without major impairment in dilator muscle activity or upper airway collapsibility. However, the magnitude of change in arousal threshold was insufficient to overcome the compromised upper airway anatomy in these patients. Keywords: Arousal, lung, muscles, respiratory physiology, sedative, sleep-disordered breathing, upper airway Citation: Eckert DJ; Malhotra A; Wellman A; White DP. Trazodone increases the respiratory arousal threshold in patients with obstructive sleep apnea and a low arousal threshold. SLEEP 2014;37(4):811-819.

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Airway Dilator Muscle Activity and Lung Volume During Stable Breathing in Obstructive Sleep Apnea

Cited by 148 publications

References 31 publications

Termination of Respiratory Events with and without Cortical Arousal in Obstructive Sleep Apnea

Termination of Respiratory Events with and without Cortical Arousal in Obstructive Sleep Apnea

Personalised medicine in sleep respiratory disorders: focus on obstructive sleep apnoea diagnosis and treatment

Trazodone Increases the Respiratory Arousal Threshold in Patients with Obstructive Sleep Apnea and a Low Arousal Threshold

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