Airway and respiratory tissue mechanics in normal infants.
Low-frequency respiratory impedance (Zrs) was measured by applying a forcing signal, between 0.5 and 21 Hz at a transrespiratory pressure of 20 cm H(2)O, in a cross-sectional study of 37 normal infants. A model containing an airway resistance (Raw) and inertance (Iaw) and a tissue damping (G) and elastance (H) was fitted to the individual Zrs. Forced expiratory volume in 0.5 second (FEV(0.5)) was determined using the raised volume rapid thoracic compression technique. Multivariate regression analysis was used to analyze the relationships between the lung function parameters and length. Both airway and tissue parameters showed a decreasing quadratic relationship with increasing length. FEV(0.5) showed an increasing cubic relationship with length. A family history of asthma was found to have a negative effect on Raw, H, and FEV(0.5).
Hall
G L
GL
Institute for Child Health Research, Department of Respiratory Medicine, Princess Margaret Hospital, and Centre for Child Health Research, University of Western Australia, Perth Australia.
Hantos
Z
Z
Peták
F
F
Wildhaber
J H
JH
Tiller
K
K
Burton
P R
PR
Sly
P D
PD
D000403:Airway Resistance / Q000502:physiology*; D000886:Anthropometry; D001249:Asthma / Q000235:genetics / Q000503:physiopathology; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D007223:Infant; D008297:Male; D012016:Reference Values; D015656:Respiratory Mechanics / Q000502:physiology*