title: Oronasal distribution of ventilation at different ages.
abstract: The route of breathing, oral or nasal, is a determinant of the doses of inhaled pollutants delivered to target sites in the upper and lower respiratory tracts. We measured partitioning of ventilation, using a divided oronasal mask during a submaximal exercise test, in 37 male and female subjects who ranged in age from 7 to 72 y. The following four patterns of breathing were evident during exercise: (1) nasal only (13.5%), nasal shifting to oronasal (40.5%), oronasal only (40.5%), and oral only (5.4%). Children (i.e., 7-16 y of age) displayed more variability than adults with respect to their patterns of ventilation with exercise. Young adults (i.e., 17-30 y of age) who initially breathed nasally with exercise switched to oral ventilation at a lower percentage of the previously measured maximum ventilation (10.8%) than older subjects (31.8%). The partitioning of ventilation between the nasal and oral routes follows complex patterns that cannot be predicted readily by the age, gender, or nasal airway resistance of the subject.
authors.affiliation: Department of Internal Medicine, University of New Mexico Medical Center, Albuquerque 87131-5306, USA.
authors.forename: D S
authors.initials: DS
authors.lastname: James
authors.forename: W E
authors.initials: WE
authors.lastname: Lambert
authors.forename: C M
authors.initials: CM
authors.lastname: Mermier
authors.forename: C A
authors.initials: CA
authors.lastname: Stidley
authors.forename: T W
authors.initials: TW
authors.lastname: Chick
authors.forename: J M
authors.initials: JM
authors.lastname: Samet
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D000403:Airway Resistance; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009058:Mouth Breathing / Q000503:physiopathology*; D009666:Nose / Q000502:physiology*; D011175:Positive-Pressure Respiration / Q000295:instrumentation; D012119:Respiration / Q000502:physiology*; D012129:Respiratory Function Tests / Q000379:methods / Q000706:statistics & numerical data