Effects of high-frequency oscillating pressures on upper airway muscles in humans

Henke, Kathe G.; Sullivan, Colin E.

doi:10.1152/jappl.1993.75.2.856

Cited by 37 publications

(36 citation statements)

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“…With the oscillation frequency applied (5 Hz) in an on/off manner, sleep was not disturbed as shown by the unchanged EEG (no arousals nor microarousals) and chin EMG. More studies are required to investigate other amplitudes and frequencies but it appears that with the low-frequency (5 Hz), low-pressure (1.5 cmH 2 O) oscillations applied in our study, reflex activity such as may occur when high frequencies (30 Hz) are applied [21], is not present. However, more sophisticated EEG analysis or needle EMG of muscle subgroups during low-frequency oscillation might clarify this point further.…”

Section: Discussionmentioning

confidence: 92%

Forced oscillation technique for the evaluation of severe sleep apnoea/hypopnoea syndrome: a pilot study

Badia¹,

Farré²,

Montserrat³

et al. 1998

Eur Respir J

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Patients with obstructive sleep apnoea/hypopnoea syndrome (SAHS) experience repeated episodes of increased upper airway resistance leading to profound disturbances in sleep architecture and arterial blood gases [1,2]. Repeated inspiratory efforts occur during an obstructive sleep apnoea until arousal ensues and airway patency is restored [3]. The increased upper airway resistance in patients with SAHS can be assessed indirectly by the analysis of different signals, such as the time profile of the inspiratory flow signal, the noise of snoring, the use of strain gauges or inductance plethysmographs [4][5][6][7]. However, as the recent description of the upper airway resistance syndrome has pointed out [8], the classical noninvasive techniques previously described are unable to detect the full range of respiratory-related flow events that occur throughout the night. A more direct quantitative approach is the recording of the inspiratory driving pressure by means of an oesophageal catheter [8][9][10], although this has limited applicability in routine studies. Accordingly, methods to quantify changes in airway resistance noninvasively are required.The forced oscillation technique (FOT) provides a noninvasive method to quantify and assess the degree of airway obstruction, thus avoiding the need for a measurement of oesophageal pressure. It consists of superimposing on spontaneous breathing a small pressure oscillation through a nasal mask attached to the patient [11]. Respiratory impedance (| Z |) is derived from pressure and flow signals recorded at the nasal mask. Because patient co-operation is not required the technique can be applied during sleep. The potential applicability of FOT to assess airway obstruction in SAHS studies has recently been substantiated in a model study [12]. | Z | measured by FOT was found to be an accurate index of overall airflow obstruction [12]. The aim of the present study was to ascertain whether FOT is applicable in human diagnostic sleep studies for noninvasive assessment of airway obstruction in SAHS patients. Specifically, we were interested in testing whether respiratory events detected by FOT corresponded with those recognized by more conventional approaches. Furthermore, we wished to establish whether the FOT could be an adequate method continuous monitoring of airway mechanics dur- The mean number of respiratory events·h -1 detected by PSG and FOT were 55±16 and 58±17, respectively, with a strong concordance. | Z | increased from a baseline of 11±4 to 50±20 cmH 2 O·L -1 ·s during apnoea (mean±SD). In all but one patient intermittent increases of | Z | occurred immediately before each obstructive apnoea. In four patients, the increases of | Z | developed at end-expiration whereas in two others occurred during inspiration. During hypopnoea most of the patients showed decreases of | Z | during expiration.In conclusion, forced oscillation technique can be used as a noninvasive and complementary tool for the diagnosis of respiratory events and provides an on-line quantitative appro...

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Section: Discussionmentioning

confidence: 92%

Forced oscillation technique for the evaluation of severe sleep apnoea/hypopnoea syndrome: a pilot study

Badia¹,

Farré²,

Montserrat³

et al. 1998

Eur Respir J

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“…These experimental conditions are very different from clinical sleep studies in the human. However, HENKE and SULLIVAN [14] have shown evidence of EMG activation in the sleeping human, both in healthy subjects and in patients with obstructive sleep apnoea [14]. The presence of arousal or microarousals leading directly to upper airway muscle activation could be a possible explanation for these divergent results.…”

Section: Discussionmentioning

confidence: 99%

“…In addition, 30 Hz was also tested in order to reproduce the methodology of the study of HENKE and SULLIVAN. [14]. It is clear that larger pressure swings applied to the upper airway will cause increased activation of local mechanoreceptors and afferent pathways.…”

Section: Discussionmentioning

confidence: 99%

“…Reflexes in response to pressure changes may play an important role in maintaining upper airway patency within the breathing cycle during sleep [7][8][9][10]. The effect of high-frequency oscillating pressures has been previously studied mainly in animals, but also in the sleeping human [11][12][13][14]. In experimental conditions, high-frequency oscillation appeared to elicit an increase in upper airway muscle activity.…”

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confidence: 99%

“…The mechanism could be a direct activation of local receptors with an input on muscle activity. However, methodological artefacts must also be considered as they are not easy to avoid and may lead to nonvisible sleep fragmentation and neurological arousal [14]. Upon applying FOT extensively in sleep studies, an investigation was designed to verify that the low-frequency and lowamplitude oscillations applied in routine measurements of airway obstruction do not have any effect on upper airway patency, upper airway muscle electromyography and electroencephalogram (EEG) in a clinical setting in patients with moderate-to-severe sleep apnoea syndrome.…”

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Forced oscillation measurements do not affect upper airway muscle tone or sleep in clinical studies

et al. 2001

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Upper airway obstruction in the sleep apnoea/hypopnoea syndrome (SAHS) can be easily assessed by measuring respiratory impedance with the forced oscillation technique (FOT). This methodology has been proposed as a useful clinical tool both for the diagnosis of sleep breathing disorders and for continuous positive airway pressure (CPAP) titration. However, previous studies suggest that the application of high-frequency pressure oscillation to the upper airway may induce changes in the electroencephalogram (EEG) or upper airway muscle function. The effect of FOT measurements on upper airway muscle tone and EEG in clinical sleep studies was examined. Seven patients with moderate SAHS were included (age: 54 ¡ 11 yrs; apnoea/hypopnoea index: 43 ¡ 21 events?h -1 ; body mass index: 30 ¡ 2 kg?m -2 ). Genioglossus surface electromyogram activity (EMGgg) and EEG signal were analysed with and without FOT application (frequency: 5 Hz and 30 Hz; peak-topeak pressure oscillation: 1 cmH 2 O) during stable sleep. Measurements were carried out in two different situations.Step 1: applying FOT during episodes of obstructive events or flow limitation; and step 2: during prolonged periods of normal breathing at optimal CPAP. The root mean square of EMGgg activity and fast Fourier analysis (alpha and delta bands) of the EEG signal were performed.The application of FOT did not increase EMGgg activity in any of the situations studied. In addition, no evidence of the effects on EEG was found: alpha/delta relationship: awake:0.70, baseline sleep:0.13, FOT(5 Hz):0.18, FOT(30 Hz):0.11.The presented results suggest that the use of forced oscillation technique over the ranges of frequency and amplitude proposed for clinical sleep studies does not induce changes in upper airway muscle activity and neurological variables in patients with sleep apnoea/hypopnoea syndrome.

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Obstructive Sleep Apnea

Bietz¹

2022

Pressure Oscillation in Biomedical Diagnostics and Therapy

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Effects of high-frequency oscillating pressures on upper airway muscles in humans

Cited by 37 publications

References 0 publications

Forced oscillation technique for the evaluation of severe sleep apnoea/hypopnoea syndrome: a pilot study

Forced oscillation technique for the evaluation of severe sleep apnoea/hypopnoea syndrome: a pilot study

Forced oscillation measurements do not affect upper airway muscle tone or sleep in clinical studies

Obstructive Sleep Apnea

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