Repeatability of a rapid dosimetric method for methacholine challenge using a pocket turbine spirometer for FEV1 measurements.
The repeatability of a rapid dosimetric method for methacholine challenge was evaluated with 11 asthmatic patients. A Spira Elektro 2 dosimeter was used for methacholine delivery and a pocket turbine spirometer (Micro Spirometer) for FEV1 measurements. Methacholine was delivered in four successive, increasing doses ranging from 80 micrograms up to a cumulative dose of 6900 micrograms. The single determination standard deviation was low (12.5%), corresponding to a 95% confidence interval of +/- 0.925 doubling doses. The mean difference (+/- SE) between measurements of log PD20 FEV1 was -0.015 (0.056), and the absolute value of the difference in log PD20 FEV1 was not significantly related to the average log PD20 FEV1 (r = -0.155, P = 0.65). The rapid dosimetric methacholine challenge test, performed with a pocket turbine spirometer, proved to be as reproducible as previous methods. Furthermore, this methacholine challenge is clearly less time consuming than conventional provocations, including bronchodilator aerosol (given to resolve post-challenge bronchoconstriction); the whole test can be performed in 20 min. This is especially valuable in epidemiologic studies, as well as in clinical practice.
Hedman
J
J
Department of Pulmonary Diseases, Päijät-Häme Central Hospital, Lahti, Finland.
Alanko
K
K
Nieminen
M M
MM
D000280:Administration, Inhalation; D000328:Adult; D001249:Asthma / Q000175:diagnosis / Q000503:physiopathology*; D016535:Bronchial Hyperreactivity / Q000175:diagnosis / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D016085:Bronchoconstrictor Agents; D004305:Dose-Response Relationship, Drug; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D015203:Reproducibility of Results; D013147:Spirometry / Q000295:instrumentation
D016085:Bronchoconstrictor Agents; D016210:Methacholine Chloride