Journal article
Effects of lung inflation on airway heterogeneity during histaminergic bronchoconstriction
Journal of applied physiology (1985), Vol.115(5), pp.626-633
09/01/2013
DOI: 10.1152/japplphysiol.00476.2013
PMCID: PMC3763068
PMID: 23813528
Abstract
Lung inflation has been shown to dilate airways by altering the mechanical equilibrium between opposing airway and parenchymal forces. However, it is not known how heterogeneously such dilation occurs throughout the airway tree. In six anesthetized dogs, we measured the diameters of five to six central airway segments using high-resolution computed tomography, along with respiratory input impedance (
Z
rs
) during generalized aerosol histamine challenge, and local histamine challenge in which the agonist was instilled directly onto the epithelia of the imaged central airways. Airway diameters and
Z
rs
were measured at 12 and 25 cmH
2
O. The
Z
rs
spectra were fitted with a model that incorporated continuous distributions of airway resistances. Airway heterogeneity was quantified using the coefficient of variation for predefined airway distribution functions. Significant reductions in average central airway diameter were observed at 12 cmH
2
O for both aerosolized and local challenges, along with significant increases upon inflation to 25 cmH
2
O. No significant differences were observed for the coefficient of variation of airway diameters under any condition. Significant increases in effective airway resistance as measured by
Z
rs
were observed only for the aerosolized challenge at 12 cmH
2
O, which was completely reversed upon inflation. We conclude that the lung periphery may be the most dominant contributor to increases in airway resistance and tissue elastance during bronchoconstriction induced by aerosolized histamine. However, isolated constriction of only a few central airway segments may also affect tissue stiffness via interdependence with their surrounding parenchyma.
Details
- Title: Subtitle
- Effects of lung inflation on airway heterogeneity during histaminergic bronchoconstriction
- Creators
- David W Kaczka - Harvard Medical School, Boston, MassachusettsWayne Mitzner - Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University, Baltimore, MarylandRobert H Brown - Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University, Baltimore, Maryland
- Resource Type
- Journal article
- Publication Details
- Journal of applied physiology (1985), Vol.115(5), pp.626-633
- DOI
- 10.1152/japplphysiol.00476.2013
- PMID
- 23813528
- PMCID
- PMC3763068
- NLM abbreviation
- J Appl Physiol (1985)
- ISSN
- 8750-7587
- eISSN
- 1522-1601
- Publisher
- American Physiological Society; Bethesda, MD
- Language
- English
- Date published
- 09/01/2013
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Radiology; Anesthesia
- Record Identifier
- 9984007164102771
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