Airway inhomogeneities contribute to apparent lung tissue mechanics during constriction

Kenneth R. Lutchen, Z. Hantos, F. Peták, A. Adamicza, Béla Suki

Research output: Contribution to journalArticle

183 Citations (Scopus)

Abstract

Recent studies have suggested that part of the measured increase in lung tissue resistance after bronchoconstriction is an artifact due to increased airway inhomogeneities. To resolve this issue, we measured lung impedance (ZL) in seven open-chest rats with the lungs equilibrated on room air and then on a mixture of neon and oxygen (NeOx). The rats were placed in a body box with the tracheal tube leading through the box wall. A broadband flow signal was delivered to the box. The signal contained seven oscillation frequencies in the 0.234- to 12.07-Hz range, which were combined to produce tidal ventilation. The ZL was measured before and after bronchoconstriction caused by infusion of methacholine (MCh). Partitioning of airway and tissue properties was achieved by fitting ZL with a model including airway resistance (Raw), airway inertance, tissue damping (G), and tissue elastance (H). We hypothesized that if the inhomogeneities were not significant, the apparent tissue properties would be independent of the resident gas, whereas Raw would scale as the ratio of viscosities. Indeed, during control conditions, the NeOx-to-air ratios for G and H were both 1.03 ± 0.04. Also, there was a small increase in lung elastance (EL) between 0.234 and 4 Hz that was similar on air and NeOx. During MCh infusion, Raw and G increased markedly (45-65%), but the increase in H was relatively small (

Original languageEnglish
Pages (from-to)1841-1849
Number of pages9
JournalJournal of Applied Physiology
Volume80
Issue number5
Publication statusPublished - May 1996

Fingerprint

Mechanics
Constriction
Neon
Lung
Bronchoconstriction
Methacholine Chloride
Air
Oxygen
Airway Resistance
Electric Impedance
Viscosity
Artifacts
Ventilation
Thorax
Gases

Keywords

  • airway constriction
  • airway resistance
  • methacholine
  • parenchymal constriction
  • parenchymal resistance

ASJC Scopus subject areas

  • Physiology
  • Endocrinology
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Airway inhomogeneities contribute to apparent lung tissue mechanics during constriction. / Lutchen, Kenneth R.; Hantos, Z.; Peták, F.; Adamicza, A.; Suki, Béla.

In: Journal of Applied Physiology, Vol. 80, No. 5, 05.1996, p. 1841-1849.

Research output: Contribution to journalArticle

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