Upper airway anesthesia reduces phasic genioglossus activity during sleep apnea.
We hypothesize that stimulation of upper-airway mechanoreceptors during obstructive apnea augments upper airway muscle activity. If so, upper-airway anesthesia (UAA) should reduce mechanoreceptor output and therefore upper-airway muscle activity. To test this hypothesis, we studied the effect of UAA on the relationship between the phasic activity of the moving-time average (MTA) of the genioglossus electromyogram (EMG-GG) and the esophageal pressure deflection (DP) during obstructive apneas in non-rapid-eye-movement (NREM) sleep in a group of six men with severe sleep apnea. Before UAA, the phasic EMG-GG was linearly related to the deflections in esophageal pressure (DP) during the last three occluded breaths (both progressively increased). After UAA, the mean ratio of EMG-GG to DP decreased to 23% of the control value, from 0.17 +/- 0.04 to 0.04 +/- 0.01 (mean +/- SEM) arbitrary units/cm H2O (p < 0.05). The mean slope of the EMG-GG-versus-DP regression lines also decreased to 23% of the control value, from 0.22 +/- 0.03 to 0.05 +/- 0.01 arbitrary units/ cm H2O (p < 0.01). These findings suggest that stimulation of upper-airway mechanoreceptors during obstructive apnea in NREM sleep augments phasic genioglossus activity.
Berry
R B
RB
Pulmonary Section, Long Beach VAMC, CA 90622, USA.
McNellis
M I
MI
Kouchi
K
K
Light
R W
RW
D000772:Anesthesia, Local; D000779:Anesthetics, Local / Q000494:pharmacology; D004576:Electromyography; D004947:Esophagus / Q000187:drug effects / Q000503:physiopathology; D006801:Humans; D007830:Larynx / Q000187:drug effects / Q000503:physiopathology; D008012:Lidocaine / Q000494:pharmacology; D008297:Male; D008465:Mechanoreceptors / Q000187:drug effects / Q000503:physiopathology; D008875:Middle Aged; D009132:Muscles / Q000187:drug effects / Q000503:physiopathology*; D011312:Pressure; D012891:Sleep Apnea Syndromes / Q000503:physiopathology*; D012894:Sleep Stages / Q000502:physiology; D014059:Tongue / Q000187:drug effects / Q000503:physiopathology*
D000779:Anesthetics, Local; D008012:Lidocaine