Influence of negative airway pressure on upper airway dynamic and impact on night-time apnea worsening.
BACKGROUND
Negative airway pressure loading such as seen during obstructive apnea/hypopnea may influence upper airway (UA) mechanical properties. We measured the effects of such loading on UA mechanical properties during wakefulness and assessed the potential link with night-time apnea worsening.


METHODS
Twitch stimulations of the phrenic nerve were applied before and after a step-by-step increase in UA suction flow in 10 sleep apnea and 10 control males.


RESULTS
Inspiratory closing pressure was lower in control than in apneic subjects. No consistent changes were observed in UA mechanical properties before and after the trial. In apneic patients, changes in the apnea index from the beginning to the end of the night correlated with changes in inspiratory closing pressure following suction flow.


CONCLUSIONS
(1) Apnea phenotype does not influence the impact of negative airway pressure on UA dynamic properties during wakefulness and (2) worsening of sleep apnea frequency during the night may relate to the exposure to recurrent UA negative pressure.
Unité de recherche en pneumologie, Centre de Recherche, Institut Universitaire de Cardiologie et de Pneumologie de Québec, 2725 chemin Sainte-Foy, Quebec City, Quebec, Canada G1V 4G5. simon.gakwaya@criucpq.ulaval.ca
Simon
S
Gakwaya
Germain
G
Ethier
Frédéric
F
Sériès
D000328:Adult; D000399:Air Pressure; D016022:Case-Control Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010791:Phrenic Nerve; D017286:Polysomnography; D015656:Respiratory Mechanics / Q000502:physiology*; D012137:Respiratory System / Q000503:physiopathology*; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*; D014851:Wakefulness / Q000502:physiology*