Upper airway muscle responsiveness to rising PCO(2) during NREM sleep.

Although pharyngeal muscles respond robustly to increasing PCO(2) during wakefulness, the effect of hypercapnia on upper airway muscle activation during sleep has not been carefully assessed. This may be important, because it has been hypothesized that CO(2)-driven muscle activation may importantly stabilize the upper airway during stages 3 and 4 sleep. To test this hypothesis, we measured ventilation, airway resistance, genioglossus (GG) and tensor palatini (TP) electromyogram (EMG), plus end-tidal PCO(2) (PET(CO(2))) in 18 subjects during wakefulness, stage 2, and slow-wave sleep (SWS). Responses of ventilation and muscle EMG to administered CO(2) (PET(CO(2)) = 6 Torr above the eupneic level) were also assessed during SWS (n = 9) or stage 2 sleep (n = 7). PET(CO(2)) increased spontaneously by 0.8 +/- 0.1 Torr from stage 2 to SWS (from 43.3 +/- 0.6 to 44.1 +/- 0.5 Torr, P < 0.05), with no significant change in GG or TP EMG. Despite a significant increase in minute ventilation with induced hypercapnia (from 8.3 +/- 0.1 to 11.9 +/- 0.3 l/min in stage 2 and 8.6 +/- 0.4 to 12.7 +/- 0.4 l/min in SWS, P < 0.05 for both), there was no significant change in the GG or TP EMG. These data indicate that supraphysiological levels of PET(CO(2)) (50.4 +/- 1.6 Torr in stage 2, and 50.4 +/- 0.9 Torr in SWS) are not a major independent stimulus to pharyngeal dilator muscle activation during either SWS or stage 2 sleep. Thus hypercapnia-induced pharyngeal dilator muscle activation alone is unlikely to explain the paucity of sleep-disordered breathing events during SWS.

[1]  D. White,et al.  Hypercapnic ventilatory response in sleeping adults. , 2015, The American review of respiratory disease.

[2]  D. White,et al.  Effect of wake‐sleep transitions and rapid eye movement sleep on pharyngeal muscle response to negative pressure in humans , 1999, The Journal of physiology.

[3]  T. Schäfer.  Variability of vigilance and ventilation: studies on the control of respiration during sleep. , 1998, Respiration physiology.

[4]  J. Trinder,et al.  Gender differences in airway resistance during sleep. , 1997, Journal of applied physiology.

[5]  R. Berry,et al.  Upper airway anesthesia reduces phasic genioglossus activity during sleep apnea. , 1997, American journal of respiratory and critical care medicine.

[6]  D. White,et al.  Influence of sleep onset on upper-airway muscle activity in apnea patients versus normal controls. , 1996, American journal of respiratory and critical care medicine.

[7]  F. Sériès,et al.  Influence of sleep on ventilatory and upper airway response to CO2 in normal subjects and patients with COPD. , 1995, American journal of respiratory and critical care medicine.

[8]  S A Shea,et al.  The effect of sleep on reflex genioglossus muscle activation by stimuli of negative airway pressure in humans. , 1994, The Journal of physiology.

[9]  D. White,et al.  Influence of sleep on response to negative airway pressure of tensor palatini muscle and retropalatal airway. , 1993, Journal of applied physiology.

[10]  D. White,et al.  Influence of sleep on genioglossus muscle activation by negative pressure in normal men. , 1993, The American review of respiratory disease.

[11]  K. Nakayama,et al.  Relaxation phenomena in the vicinity of the glass transition of poly (p‐phenylene sulfide) , 1993 .

[12]  P. L. Smith,et al.  Modulation of maximal inspiratory airflow by neuromuscular activity: effect of CO2. , 1993, Journal of applied physiology.

[13]  D. White,et al.  Influences of NREM sleep on the activity of tonic vs. inspiratory phasic muscles in normal men. , 1992, Journal of applied physiology.

[14]  D. White,et al.  Waking genioglossal electromyogram in sleep apnea patients versus normal controls (a neuromuscular compensatory mechanism). , 1992, The Journal of clinical investigation.

[15]  J. Dempsey,et al.  Effect of hypercapnia on total pulmonary resistance during wakefulness and during NREM sleep. , 1991, The American review of respiratory disease.

[16]  R. Englman,et al.  A numerical simulation of the R‐curve behavior in microcracking materials , 1991 .

[17]  D. White,et al.  Influence of sleep on tensor palatini EMG and upper airway resistance in normal men. , 1991, Journal of applied physiology.

[18]  J. Ringler,et al.  Phasic electromyographic activity of the genioglossus increases in normals during slow-wave sleep. , 1991, Respiration physiology.

[19]  K. Leo,et al.  Free‐carrier lifetime and deep‐level luminescence in semi‐insulating GaAs: The influence of indium doping and growth in a magnetic field , 1989 .

[20]  D. White,et al.  Collapsibility of the human upper airway during normal sleep. , 1989, Journal of applied physiology.

[21]  F. Sériès,et al.  Influence of respiratory drive on upper airway resistance in normal men. , 1989, Journal of applied physiology.

[22]  W. B. Van de Graaff,et al.  Thoracic influence on upper airway patency , 1988 .

[23]  J. Dempsey,et al.  Effect of airway impedance on CO2 retention and respiratory muscle activity during NREM sleep. , 1988, Journal of applied physiology.

[24]  K. Strohl,et al.  Non-muscular factors in upper airway patency in the rabbit. , 1988, Respiration physiology.

[25]  N J Douglas,et al.  Control of breathing during sleep. , 1984, Clinical science.

[26]  N. Zamel,et al.  Lung volume dependence of pharyngeal cross-sectional area in patients with obstructive sleep apnea. , 1984, The American review of respiratory disease.

[27]  C. Sullivan,et al.  Upper airway closing pressures in snorers. , 1984, Journal of applied physiology: respiratory, environmental and exercise physiology.

[28]  E. Onal,et al.  Diaphragmatic and genioglossal electromyogram responses to CO2 rebreathing in humans. , 1981, Journal of applied physiology: respiratory, environmental and exercise physiology.

[29]  R. Brouillette,et al.  A neuromuscular mechanism maintaining extrathoracic airway patency. , 1979, Journal of applied physiology: respiratory, environmental and exercise physiology.

[30]  Phillipson Ea,et al.  Control of breathing during sleep. , 1978 .

[31]  G LUNDIN,et al.  SOLUBILITY OF ACETYLENE IN LUNG TISSUE AS AN ERROR IN CARDIAC OUTPUT DETERMINATION WITH THE ACETYLENE METHOD. , 1963, Acta physiologica Scandinavica.

[32]  P. L. Smith,et al.  Neuromuscular activity and upper airway collapsibility. Mechanisms of action in the decerebrate cat. , 1997, American journal of respiratory and critical care medicine.

[33]  T. Takishima,et al.  Role of chemical drive in recruiting upper airway and inspiratory intercostal muscles in patients with obstructive sleep apnea. , 1993, The American review of respiratory disease.

[34]  J. Dempsey,et al.  Effect of sleep-induced increases in upper airway resistance on respiratory muscle activity. , 1991, Journal of applied physiology.

[35]  N. Gavriely,et al.  Effect of hypercapnia on upper airway resistance and collapsibility in anesthetized dogs. , 1989, Respiration physiology.

[36]  W. B. Van de Graaff.  Thoracic influence on upper airway patency. , 1988, Journal of applied physiology.

[37]  D. Hudgel,et al.  Mechanics of the respiratory system and breathing pattern during sleep in normal humans. , 1984, Journal of applied physiology: respiratory, environmental and exercise physiology.

[38]  A. Rechtschaffen,et al.  A manual of standardized terminology, technique and scoring system for sleep stages of human subjects , 1968 .

[39]  R. Jung,et al.  NEUROPHYSIOLOGICAL STUDIES OF ABNORMAL NIGHT SLEEP AND THE PICKWICKIAN SYNDROME. , 1965, Progress in brain research.

[40]  K. Bulow.  Respiration and wakefulness in man. , 1963, Acta physiologica Scandinavica. Supplementum.