Logo of jcinvestThe Journal of Clinical InvestigationCurrent IssueArchiveSubscriptionAbout the Journal
J Clin Invest. Dec 1972; 51(12): 3235–3243.
PMCID: PMC333005

Site of Airway Obstruction in Asthma as Determined by Measuring Maximal Expiratory Flow Breathing Air and a Helium-Oxygen Mixture

Abstract

Because maximum expiratory flow-volume rates in normal subjects are dependent on gas density, the resistance between alveoli and the point at which dynamic compression begins (Rus) is mostly due to convective acceleration and turbulence. We measured maximum expiratory flow-volume (MEFV) curves in asthmatics and chronic bronchitics breathing air and He-O2. In the latter and in some asthmatics, MEFV curves did not change, indicating that Rus is mostly due to laminar flow. Therefore, the point at which dynamic compression begins must be further upstream than in normal subjects and the site of obstruction must be in small airways. In other asthmatics, flow increased normally indicating obstruction in larger airways. The response to He-O2 did not correlate with initial values of pulmonary resistance, the initial MEFV curves or the response to bronchodilators. We conclude that the site of airway obstruction varies among asthmatics and that the site of obstruction is not detectable by measurement of the usual parameters of lung mechanics.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.2M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Hogg JC, Macklem PT, Thurlbeck WM. Site and nature of airway obstruction in chronic obstructive lung disease. N Engl J Med. 1968 Jun 20;278(25):1355–1360. [PubMed]
  • Dulfano MJ, Hewetson J. Radiologic contributions to the nosology of obstructive lung disease entities. Dis Chest. 1966 Sep;50(3):270–280. [PubMed]
  • VOGT-MOYKOPF I, LAQUA H. DIE ENDOBRONCHIALE INSTILLATION EINES BRONCHOSPASMOLYTIKUMS ZUR LOESUNG VON SPASMEN WAEHREND DER BRONCHOGRAPHIE. Thoraxchir Vask Chir. 1964 Feb;11:482–489. [PubMed]
  • Levine G, Housley E, MacLeod P, Macklem PT. Gas exchange abnormalities in mild bronchitis and asymptomatic asthma. N Engl J Med. 1970 Jun 4;282(23):1277–1282. [PubMed]
  • McFadden ER, Jr, Lyons HA. Serial studies of factors influencing airway dynamics during recovery from acute asthma attacks. J Appl Physiol. 1969 Oct;27(4):452–459. [PubMed]
  • Woolcock AJ, Vincent NJ, Macklem PT. Frequency dependence of compliance as a test for obstruction in the small airways. J Clin Invest. 1969 Jun;48(6):1097–1106. [PMC free article] [PubMed]
  • Mead J, Turner JM, Macklem PT, Little JB. Significance of the relationship between lung recoil and maximum expiratory flow. J Appl Physiol. 1967 Jan;22(1):95–108. [PubMed]
  • Macklem PT, Wilson NJ. Measurement of intrabronchial pressure in man. J Appl Physiol. 1965 Jul;20(4):653–663. [PubMed]
  • Wood LD, Bryan AC. Effect of increased ambient pressure on flow-volume curve of the lung. J Appl Physiol. 1969 Jul;27(1):4–8. [PubMed]
  • SCHILDER DP, ROBERTS A, FRY DL. EFFECT OF GAS DENSITY AND VISCOSITY ON THE MAXIMAL EXPIRATORY FLOW-VOLUME RELATIONSHIP. J Clin Invest. 1963 Nov;42:1705–1713. [PMC free article] [PubMed]
  • GRAPE B, CHANNIN E, TYLER JM. The effect of helium and oxygen mixtures on pulmonary resistances in emphysema. Am Rev Respir Dis. 1960 Jun;81:823–829. [PubMed]
  • Barnett TB. Effects of helium and oxygen mixtures on pulmonary mechanics during airway constriction. J Appl Physiol. 1967 Apr;22(4):707–713. [PubMed]
  • Macklem PT, Mead J. Factors determining maximum expiratory flow in dogs. J Appl Physiol. 1968 Aug;25(2):159–169. [PubMed]
  • MACKLEM PT, FRASER RG, BROWN WG. BRONCHIAL PRESSURE MEASUREMENTS IN EMPHYSEMA AND BRONCHITIS. J Clin Invest. 1965 Jun;44:897–905. [PMC free article] [PubMed]
  • Olsen CR, Stevens AE, McIlroy MB. Rigidity of tracheae and bronchi during muscular constriction. J Appl Physiol. 1967 Jul;23(1):27–34. [PubMed]
  • Vincent NJ, Knudson R, Leith DE, Macklem PT, Mead J. Factors influencing pulmonary resistance. J Appl Physiol. 1970 Aug;29(2):236–243. [PubMed]

Articles from The Journal of Clinical Investigation are provided here courtesy of American Society for Clinical Investigation

Formats:

Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...

Links

  • Compound
    Compound
    PubChem Compound links
  • MedGen
    MedGen
    Related information in MedGen
  • PubMed
    PubMed
    PubMed citations for these articles
  • Substance
    Substance
    PubChem Substance links

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...