Oronasal distribution of ventilation at different ages.
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.
James
D S
DS
Department of Internal Medicine, University of New Mexico Medical Center, Albuquerque 87131-5306, USA.
Lambert
W E
WE
Mermier
C M
CM
Stidley
C A
CA
Chick
T W
TW
Samet
J M
JM
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