title: [Bronchial hyperresponsiveness to methacholine assessed by means of tracheal auscultation of healthy children aged under 4 years].
abstract: OBJECTIVE
  To assess the safety of the tracheal auscultation method for measuring bronchial hyperresponsiveness in healthy unsedated children aged less than 4 years and to establish a range of normal bronchial hyperresponsiveness values.
  
  
  METHODS
  The study population consisted of healthy children aged between 6 months and 4 years. A methacholine bronchial provocation test was administered to unsedated children, using the tidal volume breathing technique and applying an abbreviated protocol. The test was considered positive when wheezing was heard in the trachea, arterial oxygen saturation (SaO2) fell by 5% or more, or respiratory rate increased by 50% or more.
  
  
  RESULTS
  A total of 16 children were studied. Ages ranged from 8 to 47 months, with a mean (SD) of 23.5 (12.2) months. There was no response to the methacholine in 11 children. In the other 5 children, there was a positive response at a concentration of 8 mg/mL. Response to the test was considered positive on the basis of tracheal wheezing in 3 cases, tracheal wheezing and a fall in SaO2 in 1 case, and a fall of SaO2 of 5% or more in 1 case. SaO2 never fell below 93%.
  
  
  CONCLUSIONS
  As a means for assessing bronchial hyperresponsiveness, the tracheal auscultation method is appropriate, is simple to apply, and can be safely administered to unsedated children aged less than 4 years. The lowest concentration at which a response to methacholine occurs in healthy children of this age group is 8 mg/mL.
authors: ABS Consell de Cent, Barcelona, España.
authors: Inés
authors: I
authors: de Mir Messa
authors: Antonio
authors: A
authors: Moreno Galdó
authors: Nicolás
authors: N
authors: Cobos Barroso
authors: Santos
authors: S
authors: Liñán Cortés
authors: Silvia
authors: S
authors: Gartner
authors: Gerardo
authors: G
authors: Vizmanos Lamotte
mesh_terms: D001249:Asthma / Q000453:epidemiology; D001314:Auscultation / Q000379:methods*; D016535:Bronchial Hyperreactivity / Q000139:chemically induced*; D001985:Bronchial Provocation Tests / Q000379:methods*; D002675:Child, Preschool; D004198:Disease Susceptibility; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D016210:Methacholine Chloride / Q000008:administration & dosage; D010100:Oxygen / Q000097:blood; D012016:Reference Values; D012135:Respiratory Sounds; D013990:Tidal Volume; D014132:Trachea
chemical_list: D016210:Methacholine Chloride; D010100:Oxygen