Clinical interpretation of airway response to a bronchodilator. Epidemiologic considerations.

Airways responsiveness to a bronchodilator is frequently measured to assist in determining the cause of respiratory symptoms. Clinically, a greater than 15% improvement in the FEV1 is often used to define the "increased" response indicative of asthma. However, unlike other tests of lung function, reference standards derived from "healthy" members of a general population sample have never been reported. As part of a health survey carried out in Alberta, Canada, 2,609 subjects completed a standardized respiratory symptom questionnaire and had FEV1 measured before and 20 min after inhaling terbutaline sulfate via a 750-ml spacer device. Among asymptomatic never-smoking subjects with a FEV1 greater than 80% of predicted, the upper 95th percentile of bronchodilator response (BDR), when expressed as 100 x (FEV1 postBDR - FEV1 preBDR)/predicted baseline FEV1 averaged 9%. This value remained remarkably stable across gender, age (7 to 75 yr), and height groups, and deviated to 6% only when baseline FEV1 was greater than 120% of predicted. Consistent with other respiratory function variables, in which the upper limit of normal is often defined as the upper 95th percentile, our population-derived reference values provide a conceptual definition of BDR that can easily be applied to define "increased" response in the clinical setting.

[1]  C. Shim Response to bronchodilators. , 1989, Clinics in chest medicine.

[2]  Anthonisen Nr,et al.  Bronchodilator response in chronic obstructive pulmonary disease. , 1986 .

[3]  J. Howick,et al.  Comparison of the effects of intravenously administered aminophylline and inhaled isoproterenol on normal airways. , 1986, The American review of respiratory disease.

[4]  A. Buist,et al.  Relationship of response to a bronchodilator and decline in forced expiratory volume in one second in population studies. , 1985, The American review of respiratory disease.

[5]  A C Degraff,et al.  The use of criteria for reversibility and obstruction to define patient groups for bronchodilator trials. Influence of clinical diagnosis, spirometric, and anthropometric variables. , 1985, The American review of respiratory disease.

[6]  K. Nugent,et al.  Bronchodilator testing: confidence intervals derived from placebo inhalations. , 2015, The American review of respiratory disease.

[7]  M. Lebowitz,et al.  Changes in the normal maximal expiratory flow-volume curve with growth and aging. , 1983, The American review of respiratory disease.

[8]  A. Wilson,et al.  Response to inhaled metaproterenol and isoproterenol in asthmatic and normal subjects. , 1980, Chest.

[9]  W. Kaltenborn,et al.  Responses to isoproterenol in a general population sample. , 1978, The American review of respiratory disease.

[10]  J. Schoenberg,et al.  Growth and decay of pulmonary function in healthy blacks and whites. , 1978, Respiration physiology.

[11]  S. E. Avner,et al.  Assessing bronchodilator responsiveness. , 1977, The Journal of allergy and clinical immunology.

[12]  R. C. Kory,et al.  Criteria for the assessment of reversibility in airways obstruction. Report of the Committee on Emphysema American College of Chest Physicians. , 1974, Chest.

[13]  B. J. Sobol,et al.  The response to isoproterenol in normal subjects and subjects with asthma. , 1974, The American review of respiratory disease.

[14]  S. F. Boushy The use of expiratory forced flows for determining response to bronchodilator therapy. , 1972, Chest.

[15]  James R. Taylor,et al.  SPIROMETRIC TESTS TO DIAGNOSE SUSPECTED ASTHMA1 , 1969 .