title: Pre/postbronchodilator interrupter resistance values in healthy young children.
abstract: The interrupter technique estimates flow resistance. It entails occlusion of the airways during tidal breathing while flow and mouth pressure are recorded. This noninvasive technique is easy to use in young children. The aim of the present study was to measure inspiratory and expiratory interrupter resistance (Rint(insp), Rint(exp)) before and after bronchodilator administration in young healthy white children. We designed a multicenter study using a standardized procedure for Rint measurements. Centers in five French cities studied 91 children (48 boys and 43 girls; height, 92 to 129 cm; mean age 5.3 +/- 1.4 years). Mean values were not significantly different for Rint(insp) and Rint(exp) (0.78 +/- 0.21 versus 0.78 +/- 0.20 KPa x L(-1) x second). However, the difference between Rint(insp) and Rint(exp) decreased significantly with age and being positive before 5 years and negative later on (p < 0.02). Rint(insp) and Rint(exp) decreased significantly with height (Rint(insp) [KPa x L(-1) x second] = 2.289 - 1.37. 10(-2) x H [cm], Rint(exp) [KPa. L(-1) x second] = 2.021 - 1.12.10(-2) x H [cm]; p < 0.001). Bronchodilator (salbutamol) administration significantly decreased Rint(insp) and Rint(exp) (p < 0.001). Bronchodilator-induced changes (% of predicted values) in mean Rint(insp) and mean Rint(exp) were -15% (95% confidence interval, -46 to +15%) and -12% (95% confidence interval, -46 to +22%), respectively. Sex did not affect pre- or postbronchodilator values. Data from the present study may prove useful for testing lung function in young children with respiratory disorders who failed to cooperate with forced expiratory maneuvers.
authors.affiliation: Physiology Department, Robert Debré Teaching Hospital, Paris, France. nicole.beydon@rbd.ap-hop-paris.fr
authors.forename: Nicole
authors.initials: N
authors.lastname: Beydon
authors.forename: Francis
authors.initials: F
authors.lastname: Amsallem
authors.forename: Michèle
authors.initials: M
authors.lastname: Bellet
authors.forename: Michèle
authors.initials: M
authors.lastname: Boule
authors.forename: Michèle
authors.initials: M
authors.lastname: Chaussain
authors.forename: André
authors.initials: A
authors.lastname: Denjean
authors.forename: Régis
authors.initials: R
authors.lastname: Matran
authors.forename: Bernard
authors.initials: B
authors.lastname: Wuyam
authors.forename: Corinne
authors.initials: C
authors.lastname: Alberti
authors.forename: Claude
authors.initials: C
authors.lastname: Gaultier
mesh_terms: D000403:Airway Resistance / Q000187:drug effects* / Q000502:physiology*; D000420:Albuterol; D000886:Anthropometry; D001993:Bronchodilator Agents; D002675:Child, Preschool; D005260:Female; D006801:Humans; D016014:Linear Models; D008170:Lung Compliance / Q000502:physiology; D008297:Male; D011336:Probability; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange / Q000187:drug effects / Q000502:physiology; D012129:Respiratory Function Tests / Q000379:methods*; D015656:Respiratory Mechanics / Q000187:drug effects / Q000502:physiology; D012680:Sensitivity and Specificity
chemical_list: D001993:Bronchodilator Agents; D000420:Albuterol