title: Prevalence and reversibility of lung hyperinflation in adult asthmatics with poorly controlled disease or significant dyspnea.
abstract: BACKGROUND
  In asthma, inflammation affects both the proximal and distal airways and may induce significant hyperinflation (HI). This study sought to evaluate the prevalence of HI in asthmatic patients with poorly controlled disease and/or dyspnea.
  
  
  METHODS
  Poor asthma control was defined by an Asthma Control Test (ACT) score <20 (n = 287), and dyspnea was defined as a modified Medical Research Council score ≥1 (n = 18). HI was defined as either a residual volume/total lung capacity (RV/TLC) above the upper limit of normal (RV-HI) or a functional residual capacity (FRC) >120% predicted (FRC-HI). HI reversibility after administration of salbutamol (400 μg) was defined as a decrease in RV >20% or a reduction in FRC >10%. Changes in dyspnea and chest tightness were evaluated on a visual analogue scale.
  
  
  RESULTS
  Both RV-HI and FRC-HI were observed in 48% of the 305 patients (mean ± SD age: 49 ± 17; FEV1 : 75 ± 18% predicted) included in the study. The prevalence of HI was higher in patients with a FEV1 <60% predicted (93% for RV-HI and 71% for FRC-HI, vs 21% and 41% in patients with a FEV1 > 80%). In patients with HI, the ACT score was lower and chest tightness higher. HI reversibility was obtained in 38% of the asthmatics with FRC-HI and 29% of the asthmatics with RV-HI, whereas FEV1 reversibility was obtained in half of these patients.
  
  
  CONCLUSIONS
  HI is highly prevalent in poorly controlled asthmatics suggesting small airway dysfunction and may represent an additional criteria for evaluating responsiveness to bronchodilators.
authors.affiliation: Service de Pneumologie et des EFR, CHU Lille, et INSERM U1019, Université Lille, Lille, France.
authors.forename: T
authors.initials: T
authors.lastname: Perez
authors.affiliation: Clinique des Bronches, Allergie et Sommeil, Hôpital Nord, Chemin des Bourrelly, Marseille, France.
authors.forename: P
authors.initials: P
authors.lastname: Chanez
authors.affiliation: Service de Pneumologie, Hôpital Cochin, AP-HP, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
authors.forename: D
authors.initials: D
authors.lastname: Dusser
authors.affiliation: UPRES EA 220, Université Versailles Saint-Quentin, Hôpital Foch, Suresnes, France.
authors.forename: P
authors.initials: P
authors.lastname: Devillier
mesh_terms: D000328:Adult; D000368:Aged; D000420:Albuterol / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy / Q000453:epidemiology* / Q000503:physiopathology*; D018450:Disease Progression; D004417:Dyspnea / Q000503:physiopathology*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D006985:Hyperventilation / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012129:Respiratory Function Tests; D012307:Risk Factors
chemical_list: D000420:Albuterol
keywords: asthma; control; lung hyperinflation; reversibility