title: Opening interrupter technique in pre-school children with chronic respiratory diseases: a perspective case-control study in the diagnosis of airway hyperesponsiveness.
abstract: BACKGROUND
  Optimal treatment for pediatric respiratory diseases is strictly related to follow-up evaluations of lung function. The aim of our study was to show the efficacy of the Opening Interrupter Technique in diagnosing the presence of airway obstruction in pre-school children.
  
  
  METHODS
  Our study was a prospective case-control study, evaluating 82 patients affected by asthma and/or cystic fibrosis (CF) and 50 healthy pre-school children, as control group. All patients were 3- to 5-years old and they were followed by our Pediatric Department, University of Catania, Italy, from February 2011 to June 2012. Measurements of respiratory resistance (o-Rint) by the opening interrupter technique were made with the MasterScreen PFT device, Jaeger GmbH, Würzburg, Germany, during quiet breathing. The presence of airway obstruction was detected as a value of o-Rint higher than two standard deviations (SD) compared with the theoretical data.
  
  
  RESULTS
  We found higher values of o-Rint in asthmatic patients than in the control group, with a high statistical difference (p < 0.0001). The same results were found when we compared patients with CF and the control group (p < 0.0001). Nevertheless, we did not find any significant statistical difference between respiratory resistances measured in asthmatic and patients with CF (p > 0.05). There was a significant inverse correlation between o-Rint and height only in asthmatic and patients with CF, but not in healthy controls (p < 0.05).
  
  
  CONCLUSIONS
  In our study, the opening interrupter technique was efficient in detecting the presence of obstruction in chronic patients affected by asthma and CF.
authors.affiliation: Operative Unit of Pediatric Pneumology, Allergology and Cystic Fibrosis, University of Catania , Catania , Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Vitaliti
authors.forename: Salvatore
authors.initials: S
authors.lastname: Leonardi
authors.forename: Mario
authors.initials: M
authors.lastname: La Rosa
mesh_terms: D000402:Airway Obstruction / Q000175:diagnosis* / Q000209:etiology; D000403:Airway Resistance / Q000502:physiology*; D001249:Asthma / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D016022:Case-Control Studies; D002675:Child, Preschool; D003550:Cystic Fibrosis / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012129:Respiratory Function Tests / Q000379:methods*