Effect of inspired air temperature on genioglossus activity during nose breathing in awake humans

Experimental data suggest the presence of sensory receptors specific to the nasopharynx that may reflexly influence respiratory activity. To investigate the effects of inspired air temperature on upper airway dilator muscle activity during nose breathing, we compared phasic genioglossus electromyograms (EMGgg) in eight normal awake adults breathing cold dry or warm humidified air through the nose. EMGgg was measured with peroral bipolar electrodes during successive trials of cold air (less than or equal to 15 degrees C) and warm air (greater than or equal to 34 degrees C) nasal breathing and quantified for each condition as percent activity at baseline (room temperature). In four of the subjects, the protocol was repeated after topical nasal anesthesia. For all eight subjects, mean EMGgg was greater during cold air breathing than during baseline (P less than 0.005) or warm air breathing (P less than 0.01); mean EMGgg during warm air breathing was not significantly changed from baseline. Nasal anesthesia significantly decreased the mean EMGgg response to cold air breathing. Nasal airway inspiratory resistance, measured by posterior rhinomanometry in six subjects under similar conditions, was no different for cold or warm air nose breathing [cold 1.4 +/- 0.7 vs. warm 1.4 +/- 1.1 (SD) cmH2O.l-1.s at 0.4 l/s flow]. These data suggest the presence of superficially located nasal cold receptors that may reflexly influence upper airway dilating muscle activity independently of pressure changes in awake normal humans.

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Breathing route influences upper airway muscle activity in awake normal adults

Journal of Applied Physiology ◽

10.1152/jappl.1989.66.4.1766 ◽

1989 ◽

Vol 66 (4) ◽

pp. 1766-1771 ◽

Cited By ~ 50

Author(s):

R. C. Basner ◽

P. M. Simon ◽

R. M. Schwartzstein ◽

S. E. Weinberger ◽

J. W. Weiss

Keyword(s):

Muscle Activity ◽

Minute Ventilation ◽

Statistical Significance ◽

Upper Airway ◽

Mouth Breathing ◽

Emg Activity ◽

Electromyographic Activity ◽

Bipolar Electrodes ◽

Inspiratory Resistance ◽

Topical Nasal Anesthesia

Both nasal obstruction and nasal anesthesia result in disordered breathing during sleep in humans, and bypassing the nasal route during tidal breathing in experimental animals produces decreased electromyographic activity of upper airway (UA) dilating muscles. To investigate UA responses to breathing route in normal awake humans, we studied eight healthy males (ages 21–38 yr) during successive trials of voluntary nose breathing (N), voluntary mouth breathing (M), and mouth breathing with nose occluded (MO). We measured genioglossus electromyographic activity (EMGgg) with perorally inserted bipolar electrodes, alae nasi (EMGan) and diaphragm EMG activity (EMGdi) with surface electrodes, and minute ventilation (VE) with a pneumotachograph. Mean phasic inspiratory EMG activity of both UA muscles was significantly greater during N than during M or MO, even when a 2.5-cmH2O.l-1.s inspiratory resistance was added to MO (P less than 0.01). In contrast, neither EMGdi nor VE was consistently affected by breathing route. EMGgg during N was significantly decreased after selective topical nasal anesthesia (P less than 0.002); a decrease in EMGan did not achieve statistical significance. These data suggest that peak UA dilating muscle activity may be modulated by superficial receptors in the nasal mucosa sensitive to airflow.

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Upper airway muscle activity in normal women: influence of hormonal status

Journal of Applied Physiology ◽

10.1152/jappl.1998.84.3.1055 ◽

1998 ◽

Vol 84 (3) ◽

pp. 1055-1062 ◽

Cited By ~ 185

Author(s):

Rainer M. Popovic ◽

David P. White

Keyword(s):

Postmenopausal Women ◽

Muscle Activity ◽

Airway Resistance ◽

Upper Airway ◽

Resistive Load ◽

Substantial Impact ◽

Upper Airway Resistance ◽

Female Hormones ◽

Dilator Muscle ◽

Obstructive Sleep

Obstructive sleep apnea is a disorder with a strong male predominance. One possible explanation could be an effect of female hormones on pharyngeal dilator muscle activity. Therefore, we determined the level of awake genioglossus electromyogram (EMGgg) and upper airway resistance in 12 pre- and 12 postmenopausal women under basal conditions and during the application of an inspiratory resistive load (25 cmH2O ⋅ l−1 ⋅ s). In addition, a subgroup of eight postmenopausal women were studied a second time after 2 wk of combined estrogen and progesterone replacement in standard doses. Peak phasic and tonic genioglossus activity, expressed as a percentage of maximum, were highest in the luteal phase of the menstrual cycle (phasic 23.9 ± 3.8%, tonic 10.2 ± 1.0%), followed by the follicular phase (phasic 15.5 ± 2.2%, tonic 7.3 ± 0.8%), and were lowest in the postmenopausal group (phasic 11.3 ± 1.6%, tonic of 5.0 ± 0.6), whereas upper airway resistance did not differ. There was a weak but significant positive correlation between progesterone levels and both peak phasic ( P < 0.05) and tonic ( P < 0.01) EMGgg. Finally, there was a significant increase in EMGgg in the postmenopausal group restudied after hormone therapy. In conclusion, female hormones (possibly progesterone) have a substantial impact on upper airway dilator muscle activity.

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The effects of noradrenergic and antimuscarinic agents on upper airway dilator muscle activity, breathing and sleep in healthy individuals

Journal of Sleep Research ◽

10.1111/jsr.65_12618 ◽

2017 ◽

Vol 26 ◽

pp. 30-31

Keyword(s):

Muscle Activity ◽

Upper Airway ◽

Healthy Individuals ◽

Antimuscarinic Agents ◽

Dilator Muscle

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Reduced genioglossal activity with upper airway anesthesia in awake patients with OSA

Journal of Applied Physiology ◽

10.1152/jappl.2000.88.4.1346 ◽

2000 ◽

Vol 88 (4) ◽

pp. 1346-1354 ◽

Cited By ~ 40

Author(s):

Robert B. Fogel ◽

Atul Malhotra ◽

Steven A. Shea ◽

Jill K. Edwards ◽

David P. White

Keyword(s):

Muscle Activity ◽

Upper Airway ◽

Significant Rise ◽

Tidal Breathing ◽

Airflow Resistance ◽

Dilator Muscle ◽

Obstructive Sleep ◽

Airway Mechanics ◽

Airway Collapsibility ◽

Negative Airway Pressure

We examined whether topical upper airway anesthesia leads to a reduction in genioglossal (GG) electromyogram (EMG) in patients with obstructive sleep apnea (OSA). Airway mechanics were also evaluated. In 13 patients with OSA, we monitored GG EMG during tidal breathing and during the application of pulses of negative airway pressure (−10 to −12 cmH2O). Airflow resistance and airway collapsibility were determined. All measurements were performed with and without topical anesthesia (lidocaine). Anesthesia led to a significant fall in the peak GG EMG response to negative pressure from 36.1 ± 4.7 to 24.8 ± 5.3% (SE) of maximum ( P < 0.01). This was associated with a fall in phasic and tonic EMG during tidal breathing (phasic from 24.4 ± 4.1 to 16.4 ± 3.4% of maximum and tonic from 10.9 ± 1.6 to 8.0 ± 1.3% of maximum, P < 0.01). A significant rise in pharyngeal airflow resistance was also observed. Our results demonstrate that topical receptor mechanisms in the nasopharynx importantly influence dilator muscle activity and are likely important in driving the augmented dilator muscle activity seen in the apnea patient.

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Neostigmine but not sugammadex impairs upper airway dilator muscle activity and breathing

British Journal of Anaesthesia ◽

10.1093/bja/aen176 ◽

2008 ◽

Vol 101 (3) ◽

pp. 344-349 ◽

Cited By ~ 55

Author(s):

M. Eikermann ◽

S. Zaremba ◽

A. Malhotra ◽

A.S. Jordan ◽

C. Rosow ◽

...

Keyword(s):

Muscle Activity ◽

Upper Airway ◽

Dilator Muscle

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Differential Effects of Isoflurane and Propofol on Upper Airway Dilator Muscle Activity and Breathing

Anesthesiology ◽

10.1097/aln.0b013e31816c8a60 ◽

2008 ◽

Vol 108 (5) ◽

pp. 897-906 ◽

Cited By ~ 27

Author(s):

Matthias Eikermann ◽

Atul Malhotra ◽

Philipp Fassbender ◽

Sebastian Zaremba ◽

Amy S. Jordan ◽

...

Keyword(s):

Carbon Dioxide ◽

Flow Rate ◽

Muscle Activity ◽

Upper Airway ◽

Respiratory Drive ◽

Apparent Paradox ◽

Arterial Blood ◽

Dilator Muscle ◽

Spontaneously Breathing ◽

Intact Rats

Background Anesthesia impairs upper airway integrity, but recent data suggest that low doses of some anesthetics increase upper airway dilator muscle activity, an apparent paradox. The authors sought to understand which anesthetics increase or decrease upper airway dilator muscle activity and to study the mechanisms mediating the effect. Methods The authors recorded genioglossus electromyogram, breathing, arterial blood pressure, and expiratory carbon dioxide in 58 spontaneously breathing rats at an estimated ED50 (median effective dose) of isoflurane or propofol. The authors further evaluated the dose-response relations of isoflurane under different study conditions: (1) normalization of mean arterial pressure, or end-expiratory carbon dioxide; (2) bilateral lesion of the Kölliker-Fuse nucleus; and (3) vagotomy. To evaluate whether the markedly lower inspiratory genioglossus activity during propofol could be recovered by increasing flow rate, a measure of respiratory drive, the authors performed an additional set of experiments during hypoxia or hypercapnia. Results In vagally intact rats, tonic and phasic genioglossus activity were markedly higher with isoflurane compared with propofol. Both anesthetics abolished the genioglossus negative pressure reflex. Inspiratory flow rate and anesthetic agent predicted independently phasic genioglossus activity. Isoflurane dose-dependently decreased tonic and increased phasic genioglossus activity, and increased flow rate, and its increasing effects were abolished after vagotomy. Impairment of phasic genioglossus activity during propofol anesthesia was reversed during evoked increase in respiratory drive. Conclusion Isoflurane compared with propofol anesthesia yields higher tonic and phasic genioglossus muscle activity. The level of respiratory depression rather than the level of effective anesthesia correlates closely with the airway dilator muscle function during anesthesia.

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Geniohyoid muscle activity in normal men during wakefulness and sleep

Journal of Applied Physiology ◽

10.1152/jappl.1990.69.4.1262 ◽

1990 ◽

Vol 69 (4) ◽

pp. 1262-1269 ◽

Cited By ~ 51

Author(s):

D. A. Wiegand ◽

B. Latz ◽

C. W. Zwillich ◽

L. Wiegand

Keyword(s):

Eye Movement ◽

Rem Sleep ◽

Muscle Activity ◽

Sleep Stage ◽

Upper Airway ◽

Rapid Eye Movement ◽

Nasal Breathing ◽

Sleep Study ◽

Pharyngeal Airway ◽

Normal Men

Reduction in the activity of upper airway "dilator" muscles during sleep may allow the pharyngeal airway to collapse in some individuals. However, quantitative studies concerning the effect of sleep on specific upper airway muscles that may influence pharyngeal patency are sparse and inconclusive. We studied seven normal men (mean age 27, range 22-37 yr) during a single nocturnal sleep study and recorded sleep staging parameters, ventilation, and geniohyoid muscle electromyogram (EMGgh) during nasal breathing throughout the night. Anatomic landmarks for placement of intramuscular geniohyoid recording electrodes were determined from a cadaver study. These landmarks were used in percutaneous placement of wire electrodes, and raw and moving-time-averaged EMGgh activities were recorded. Sleep stage was determined using standard criteria. Stable periods of wakefulness and non-rapid-eye-movement (NREM) and rapid-eye-movement (REM) sleep were selected for analysis. The EMGgh exhibited phasic inspiratory activity during wakefulness and sleep in all subjects. In six of seven subjects, mean and peak inspiratory EMGgh activities were significant (P less than 0.05) reduced during stages 2 and 3/4 NREM sleep and REM sleep compared with wakefulness. This reduction of EMGgh activity was shown to result from a sleep-related decline in the level of tonic muscle activity. Phasic inspiratory EMGgh activity during all stages of sleep was not significantly different from that during wakefulness. Of interest, tonic, phasic, and peak EMGgh activities were not significantly reduced during REM sleep compared with any other sleep stage in any subject. In addition, the slope of onset of phasic EMGgh activity was not different during stage 2 NREM and REM sleep compared with wakefulness in these subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

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