Abstract
It has been suggested that in normal subjects inhaled anticholinergic agents have a preferential dilating effect on large central airways. We therefore studied 21 patients with asthma to see if response to inhaled ipratropium bromide was related to the initial central or peripheral site of major airway narrowing. Fourteen out of 21 patients with asthma increased their Vmax more than 10% after ipratropium but when assessed by air and helium/oxygen (He/O2) flow-volume curves, responders and non-responders to He/O2 breathing were divided equally between those who benefited from the drug, and those who did not. There were no significant differences in percentage improvement in Vmax between initial responders, and initial non-responders to He/O2 breathing. Furthermore the results from air and He/O2 flow-volume curves suggest that, contrary to some previous reports (not in asthmatics), inhaled ipratropium has a generalised action throughout the airways. There were no differences in severity of airflow obstruction, nor in age, sex, smoking history, or atopic status between those who benefited from ipratropium and those who did not. However, those improving after the drug had a significantly longer history of asthma than those who did not.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Antic R., Macklem P. T. The influence of clinical factors on site of airway obstruction in asthma. Am Rev Respir Dis. 1976 Nov;114(5):851–859. doi: 10.1164/arrd.1976.114.5.851. [DOI] [PubMed] [Google Scholar]
- De Troyer A., Yernault J. C., Rodenstein D. Effects of vagal blockade on lung mechanics in normal man. J Appl Physiol Respir Environ Exerc Physiol. 1979 Feb;46(2):217–226. doi: 10.1152/jappl.1979.46.2.217. [DOI] [PubMed] [Google Scholar]
- Despas P. J., Leroux M., Macklem P. T. Site of airway obstruction in asthma as determined by measuring maximal expiratory flow breathing air and a helium-oxygen mixture. J Clin Invest. 1972 Dec;51(12):3235–3243. doi: 10.1172/JCI107150. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dosman J., Bode F., Urbanetti J., Martin R., Macklem P. T. The Use of a Helium-Oxygen Mixture during Maximum Expiratory Flow to Demonstrate Obstruction in Small Airways in Smokers. J Clin Invest. 1975 May;55(5):1090–1099. doi: 10.1172/JCI108010. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Douglas N. J., Davidson I., Sudlow M. F., Flenley D. C. Bronchodilatation and the site of airway resistance in severe chronic bronchitis. Thorax. 1979 Feb;34(1):51–56. doi: 10.1136/thx.34.1.51. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Douglas N. J., Sudlow M. F., Flenley D. C. Effect of an inhaled atropinelike agent on normal airway function. J Appl Physiol Respir Environ Exerc Physiol. 1979 Feb;46(2):256–262. doi: 10.1152/jappl.1979.46.2.256. [DOI] [PubMed] [Google Scholar]
- Hensley M. J., O'Cain C. F., McFadden E. R., Jr, Ingram R. H., Jr Distribution of bronchodilatation in normal subjects: beta agonist versus atropine. J Appl Physiol Respir Environ Exerc Physiol. 1978 Nov;45(5):778–782. doi: 10.1152/jappl.1978.45.5.778. [DOI] [PubMed] [Google Scholar]
- Ingram R. H., Jr, Wellman J. J., McFadden E. R., Jr, Mead J. Relative contributions of large and small airways to flow limitation in normal subjects before and after atropine and isoproterenol. J Clin Invest. 1977 Apr;59(4):696–703. doi: 10.1172/JCI108688. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mink S., Ziesmann M., Wood L. D. Mechanisms of increased maximum expiratory flow during HeO2 breathing in dogs. J Appl Physiol Respir Environ Exerc Physiol. 1979 Sep;47(3):490–502. doi: 10.1152/jappl.1979.47.3.490. [DOI] [PubMed] [Google Scholar]