Comparison of the provocative concentration of methacholine causing a 20% fall in FEV1 between the AeroEclipse II breath-actuated nebulizer and the wright nebulizer in adult subjects with asthma

Ann Am Thorac Soc. 2015 Jul;12(7):1039-43. doi: 10.1513/AnnalsATS.201412-571BC.


Rationale: The American Thoracic Society guidelines for methacholine testing for the diagnosis of asthma recommends the 2-minute tidal breathing protocol with the Wright nebulizer, which produces more aerosol than required, generates a small particle size, and requires cleaning between tests.

Objectives: To evaluate methacholine testing using a disposable, breath-actuated AeroEclipse II, which produces aerosol during inspiration and was developed for single-patient use.

Methods: Forty-six adult subjects with asthma (19 men), aged 27.3 (SD, 9.5) years, with FEV1 98.5 (SD, 18.1) % predicted participated in a randomized, crossover, observational study. Subjects were first screened using the Wright nebulizer, then assigned to 2 minutes of tidal breathing from the Wright or 20 seconds of tidal breathing from the AeroEclipse nebulizer on 2 separate days, in random order. Provocative concentration of methacholine causing a 20% fall in FEV1 (PC20) values were calculated by linear interpolation of log dose-versus-response curves, log-transformed, and compared using paired Student t test and Pearson correlation.

Measurements and main results: The 38 subjects demonstrating reproducible PC20 measurements of within 1.5 doubling concentrations were included in the comparison. The geometric mean methacholine PC20 measured with the AeroEclipse nebulizer was approximately 1 doubling concentration lower than the geometric mean methacholine PC20 of the Wright nebulizer (P < 0.05). The Pearson correlation coefficient between the two nebulizers was 0.86 (P < 0.05).

Conclusions: The PC20 measurements using the two nebulizers were highly correlated; however, the PC20 determined with the AeroEclipse nebulizer was significantly lower than those determined using the Wright nebulizer. Clinical trial registered with (NCT 01919424).

Trial registration: NCT01919424.

Keywords: airway hyperresponsiveness; asthma; nebulizer.

Publication types

  • Comparative Study
  • Observational Study
  • Randomized Controlled Trial

MeSH terms

  • Administration, Inhalation
  • Adolescent
  • Adult
  • Asthma / diagnosis*
  • Asthma / physiopathology*
  • Bronchial Hyperreactivity / physiopathology*
  • Bronchial Provocation Tests / methods*
  • Cross-Over Studies
  • Female
  • Humans
  • Male
  • Methacholine Chloride / analysis*
  • Nebulizers and Vaporizers / classification*
  • Young Adult


  • Methacholine Chloride

Associated data