THE RELATIONSHIP BETWEEN T(PTEF)T(E) AND SPECIFIC AIRWAY CONDUCTANCE IN INFANCY

Citation
Ca. Dezateux et al., THE RELATIONSHIP BETWEEN T(PTEF)T(E) AND SPECIFIC AIRWAY CONDUCTANCE IN INFANCY, Pediatric pulmonology, 18(5), 1994, pp. 299-307
Citations number
16
Categorie Soggetti
Respiratory System",Pediatrics
Journal title
ISSN journal
87556863
Volume
18
Issue
5
Year of publication
1994
Pages
299 - 307
Database
ISI
SICI code
8755-6863(1994)18:5<299:TRBTAS>2.0.ZU;2-8
Abstract
This study examines the association between the time taken to achieve peak tidal expiratory flow as a proportion of total expiratory time (t (PTEF).t(E)) and specific airways conductance (SG(aw)) in healthy infa nts and those with prior physician diagnosed, associated, lower respir atory illness with wheezing (prior LRI) during the first year of life. We compared t(PTEF).t(E) and SG(aw) the latter estimated during both initial inspiration (II) and end-expiration (EE), in 168 infants (94 m ales), measured on 220 occasions. Mean (range) t(PTEF).t(E) was 0.321 (0.150-0.522) in 73 healthy infants aged less than 3 months (mean, 7.8 weeks), in whom mean (range) EE SG(aw) and plethysmographic thoracic gas volume at functional residual capacity (FRC(pleth)) were 2.47 s(-1 ) kPa(-1) (0.6-5.8) and 141 mL(87-204), respectively. Both t(PTEF).t(E ) and EE SG(aw) were significantly lower in older infants with prior L RI (n = 79; mean age, 50.0 weeks) compared to a similarly aged group o f healthy infants (n = 68; mean age, 48.5 weeks), the mean difference [95% confidence intervals (CI)] being -0.039 (-0.013, -0.064) and -0.4 8 s(-1) kPa(-1) (-0.24, -0.72), respectively. A significant but weak a ssociation between t(PTEF).t(E) and EE SG(aw) was found among infants above 3 months of age, irrespective of prior wheezing status. However, this relationship was not significant in healthy younger infants, in whom a significant but weak association with FRC(pleth) was found. Fur ther work is needed to elucidate the factors influencing tidal expirat ory flow patterns in infancy. (C) 1994 Wiley-Liss, Inc.