title: Partitioning of inhaled ventilation between the nasal and oral routes during sleep in normal subjects.
abstract: The oral and nasal contributions to inhaled ventilation were simultaneously quantified during sleep in 10 healthy subjects (5 men, 5 women) aged 43 +/- 5 yr, with normal nasal resistance (mean 2.0 +/- 0.3 cmH(2)O. l(-1). s(-1)) by use of a divided oral and nasal mask. Minute ventilation awake (5.9 +/- 0.3 l/min) was higher than that during sleep (5.2 +/- 0.3 l/min; P < 0.0001), but there was no significant difference in minute ventilation between different sleep stages (P = 0.44): stage 2 5.3 +/- 0.3, slow-wave 5.2 +/- 0.2, and rapid-eye-movement sleep 5.2 +/- 0.2 l/min. The oral fraction of inhaled ventilation during wakefulness (7.6 +/- 4%) was not significantly different from that during sleep (4.3 +/- 2%; mean difference 3.3%, 95% confidence interval -2.1-8.8%, P = 0.19), and no significant difference (P = 0.14) in oral fraction was observed between different sleep stages: stage two 5.1 +/- 2.8, slow-wave 4.2 +/- 1.8, rapid-eye-movement 3.1 +/- 1.7%. Thus the inhaled oral fraction in normal subjects is small and does not change significantly with sleep stage.
authors.affiliation: Department of Medicine, Queen's University, Kingston, Ontario, Canada K7L 3N6.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Fitzpatrick
authors.forename: Helen S
authors.initials: HS
authors.lastname: Driver
authors.forename: Neela
authors.initials: N
authors.lastname: Chatha
authors.forename: Nha
authors.initials: N
authors.lastname: Voduc
authors.forename: Alison M
authors.initials: AM
authors.lastname: Girard
mesh_terms: D000328:Adult; D000368:Aged; D000402:Airway Obstruction / Q000503:physiopathology; D000403:Airway Resistance / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009058:Mouth Breathing / Q000503:physiopathology*; D017286:Polysomnography; D012121:Respiration, Artificial; D015656:Respiratory Mechanics / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D012894:Sleep Stages / Q000502:physiology; D012913:Snoring / Q000503:physiopathology