Abstract
We used respiratory inductance plethysmography to record tidal respiration in 27 healthy unsedated infants and children 1 mo to 8 yr of age during sleep. Rib cage and abdominal outputs were present at approximately equal gains and summed to obtain an estimate of volume. Flow-volume curves were generated from the uncalibrated volume signal and its flow derivative. Expiratory time constants (τ) were obtained by visually drawing a line through the linear portion of the expiratory flow-volume relationship. τ increased significantly during the first 10 mo of life. After 10 mo, the estimated rate of increase of τ for older children was <5% of the estimated initial rate and not significantly different from zero. Prolongation of τ was paralleled by an increase in expiratory time (TE), and no changes in TE/τ were observed in the first 2 yr of life. These changes in τ likely reflect the increase in lung compliance induced by rapid alveolar growth during infancy. After the first year, expiratory time constants appear to remain relatively constant and may be consistent with balanced changes in compliance and resistance beyond infancy.
| Original language | English |
|---|---|
| Pages (from-to) | 2112-2115 |
| Number of pages | 4 |
| Journal | Journal of Applied Physiology |
| Volume | 67 |
| Issue number | 5 |
| State | Published - Dec 1 1989 |
| Externally published | Yes |
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Keywords
- lung growth
- Respiratory inductance plethysmography
- respiratory system compliance
- respiratory system resistance
ASJC Scopus subject areas
- Endocrinology
- Physiology
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation
Cite this
Changes of time constants during infancy and early childhood. / Ratjen, F. A.; Colin, Andrew; Stark, A. R.; Mead, J.; Wohl, M. E B.
In: Journal of Applied Physiology, Vol. 67, No. 5, 01.12.1989, p. 2112-2115.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Changes of time constants during infancy and early childhood
AU - Ratjen, F. A.
AU - Colin, Andrew
AU - Stark, A. R.
AU - Mead, J.
AU - Wohl, M. E B
PY - 1989/12/1
Y1 - 1989/12/1
N2 - We used respiratory inductance plethysmography to record tidal respiration in 27 healthy unsedated infants and children 1 mo to 8 yr of age during sleep. Rib cage and abdominal outputs were present at approximately equal gains and summed to obtain an estimate of volume. Flow-volume curves were generated from the uncalibrated volume signal and its flow derivative. Expiratory time constants (τ) were obtained by visually drawing a line through the linear portion of the expiratory flow-volume relationship. τ increased significantly during the first 10 mo of life. After 10 mo, the estimated rate of increase of τ for older children was <5% of the estimated initial rate and not significantly different from zero. Prolongation of τ was paralleled by an increase in expiratory time (TE), and no changes in TE/τ were observed in the first 2 yr of life. These changes in τ likely reflect the increase in lung compliance induced by rapid alveolar growth during infancy. After the first year, expiratory time constants appear to remain relatively constant and may be consistent with balanced changes in compliance and resistance beyond infancy.
AB - We used respiratory inductance plethysmography to record tidal respiration in 27 healthy unsedated infants and children 1 mo to 8 yr of age during sleep. Rib cage and abdominal outputs were present at approximately equal gains and summed to obtain an estimate of volume. Flow-volume curves were generated from the uncalibrated volume signal and its flow derivative. Expiratory time constants (τ) were obtained by visually drawing a line through the linear portion of the expiratory flow-volume relationship. τ increased significantly during the first 10 mo of life. After 10 mo, the estimated rate of increase of τ for older children was <5% of the estimated initial rate and not significantly different from zero. Prolongation of τ was paralleled by an increase in expiratory time (TE), and no changes in TE/τ were observed in the first 2 yr of life. These changes in τ likely reflect the increase in lung compliance induced by rapid alveolar growth during infancy. After the first year, expiratory time constants appear to remain relatively constant and may be consistent with balanced changes in compliance and resistance beyond infancy.
KW - lung growth
KW - Respiratory inductance plethysmography
KW - respiratory system compliance
KW - respiratory system resistance
UR - http://www.scopus.com/inward/record.url?scp=0024815144&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0024815144&partnerID=8YFLogxK
M3 - Article
C2 - 2600037
AN - SCOPUS:0024815144
VL - 67
SP - 2112
EP - 2115
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 5
ER -