Changes of time constants during infancy and early childhood

F. A. Ratjen, Andrew Colin, A. R. Stark, J. Mead, M. E B Wohl

Research output: Contribution to journalArticle

9 Citations (Scopus)

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 languageEnglish
Pages (from-to)2112-2115
Number of pages4
JournalJournal of Applied Physiology
Volume67
Issue number5
StatePublished - Dec 1 1989
Externally publishedYes

Fingerprint

Lung Compliance
Plethysmography
Compliance
Sleep
Respiration
Growth
Rib Cage

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

Ratjen, F. A., Colin, A., Stark, A. R., Mead, J., & Wohl, M. E. B. (1989). Changes of time constants during infancy and early childhood. Journal of Applied Physiology, 67(5), 2112-2115.

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 journalArticle

Ratjen, FA, Colin, A, Stark, AR, Mead, J & Wohl, MEB 1989, 'Changes of time constants during infancy and early childhood', Journal of Applied Physiology, vol. 67, no. 5, pp. 2112-2115.
Ratjen FA, Colin A, Stark AR, Mead J, Wohl MEB. Changes of time constants during infancy and early childhood. Journal of Applied Physiology. 1989 Dec 1;67(5):2112-2115.
Ratjen, F. A. ; Colin, Andrew ; Stark, A. R. ; Mead, J. ; Wohl, M. E B. / Changes of time constants during infancy and early childhood. In: Journal of Applied Physiology. 1989 ; Vol. 67, No. 5. pp. 2112-2115.
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