title: Methacholine challenge testing: safety of low starting FEV1. Asthma Clinical Research Network (ACRN).
abstract: OBJECTIVE
  The lower limit for the baseline value to initiate methacholine bronchial hyperresponsiveness testing has not been well established. Recommendations have varied from > 1 L to above 80% of predicted. The objective was to determine if an FEV1 < 60% predicted was acceptable.
  
  
  METHODS
  Retrospective analysis of challenges in 88 patients with a baseline FEV1 of < 60% predicted (mean=45.8%; range, 22 to 59%.
  
  
  METHODS
  Academic institutions.
  
  
  RESULTS
  There were only four individuals whose FEV1 did not return to > 90% of baseline following one poststudy beta2-agonist treatment. All four responded to a second treatment. There were no adverse sequelae following challenge in any individual. Neither age (up to 79 years) nor gender influenced outcome.
  
  
  CONCLUSIONS
  In chronic moderate to severe asthma, it appears that bronchial hyperresponsiveness testing can be safely performed even in those patients with a low baseline FEV1.
authors.affiliation: National Jewish Center for Immunology and Respiratory Medicine, Denver, CO 80206, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Martin
authors.forename: J S
authors.initials: JS
authors.lastname: Wanger
authors.forename: C G
authors.initials: CG
authors.lastname: Irvin
authors.forename: B
authors.initials: B
authors.lastname: Bucher Bartelson
authors.forename: R M
authors.initials: RM
authors.lastname: Cherniack
mesh_terms: D000318:Adrenergic beta-Agonists / Q000627:therapeutic use; D000368:Aged; D001249:Asthma / Q000175:diagnosis* / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000175:diagnosis* / Q000503:physiopathology; D001985:Bronchial Provocation Tests / Q000009:adverse effects; D016085:Bronchoconstrictor Agents / Q000009:adverse effects; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D016210:Methacholine Chloride / Q000009:adverse effects; D008875:Middle Aged; D012189:Retrospective Studies; D012449:Safety
chemical_list: D000318:Adrenergic beta-Agonists; D016085:Bronchoconstrictor Agents; D016210:Methacholine Chloride