title: Modulation of airway caliber by deep inhalation in children.
abstract: To elucidate whether deep inhalation (DI) modulates changes in airway caliber in childhood, we measured the effect of DI on respiratory impedance before and after inhaled methacholine or salbutamol in 4- to 7-yr-old children (n = 15) suffering from recurrent wheezing. In all children, the real part of impedance between 12 and 16 Hz (Re[Z](12-16)) increased after methacholine from 5.6 +/- 1.2 to 8.2 +/- 1.6 cmH(2)O. l(-1). s (P < 0.001) and resonance frequency from 18 +/- 3 to 25 +/- 5 Hz (P < 0.001). These changes were partially reversed by DI: Re[Z](12-16) decreased to 7.2 +/- 1.2 cmH(2)O. l(-1). s (P < 0.01) and resonance frequency to 19 +/- 5 Hz (P < 0.001). In nine children, on a separate occasion, Re[Z](12-16) decreased after salbutamol from 8.3 +/- 1.9 to 5.1 +/- 0.9 cmH(2)O. l(-1). s (P < 0.001) and resonance frequency from 21 +/- 6 to 15 +/- 3 Hz (P < 0.05). The decrease of Re[Z](12-16) was partially reversed by DI (to 6.2 +/- 1.4 cmH(2)O. l(-1). s, P < 0. 01), but resonance frequency did not change significantly (P = 0.75). We conclude that in 4- to 7-yr-old children pharmacologically induced changes in airway caliber are modulated by DI. These findings suggest that airway-to-parenchyma interdependence is operative in this age range.
authors.affiliation: Centro di Fisiopatologia Respiratoria, Dipartimento di Scienze Motorie e Riabilitative e Clinica delle Malattie dell' Apparato Respiratorio ed Allergologia, Dipartimento di Medicina Interna, Università di Genova, 16132 Genova, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Milanese
authors.forename: C
authors.initials: C
authors.lastname: Mondino
authors.forename: M
authors.initials: M
authors.lastname: Tosca
authors.forename: G W
authors.initials: GW
authors.lastname: Canonica
authors.forename: V
authors.initials: V
authors.lastname: Brusasco
mesh_terms: D000403:Airway Resistance / Q000187:drug effects* / Q000502:physiology; D000420:Albuterol / Q000494:pharmacology; D016084:Bronchoconstriction; D016085:Bronchoconstrictor Agents / Q000494:pharmacology; D001993:Bronchodilator Agents / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D001239:Inhalation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D016210:Methacholine Chloride / Q000494:pharmacology; D012135:Respiratory Sounds / Q000503:physiopathology*
chemical_list: D016085:Bronchoconstrictor Agents; D001993:Bronchodilator Agents; D016210:Methacholine Chloride; D000420:Albuterol