Regional diffusing capacity in normal lungs during a slow exhalation.

Journal Article (Journal Article)

From an analysis of carbon monoxide uptake and xenon-133 distribution after two bolus inhalations of these gases, we calculated regional diffusing capacity in the upper and lower volume halves of the lungs during the middle 60% of an exhaled vital capacity in five seated normal subjects. We found that the regional diffusing capacity of the upper half of the lungs was 11.6 +/- 4.2 (mean +/- SD) ml.min-1.Torr-1 and that the regional diffusing capacity of the lower half of the lungs was 24.4 +/- 2.4 ml.min-1.Torr-1 after 25% of the vital capacity had been exhaled. These values remained relatively constant as lung volume decreased from 25 to 75% of the exhaled vital capacity. Diffusing capacity in the upper half of the lungs ranged from 9.4 to 12.4 ml.min-1.Torr-1 during exhalation, and in the lower half of the lungs from 21.0 to 28.6 ml.min-1.Torr-1 during exhalation. These results suggest that total lung diffusing capacity remains relatively constant over this midrange of lung volumes and that this occurs because the regional diffusing capacities in both the upper and lower halves of the lungs remain relatively constant.

Full Text

Duke Authors

Cited Authors

  • MacIntyre, NR; Nadel, JA

Published Date

  • June 1982

Published In

Volume / Issue

  • 52 / 6

Start / End Page

  • 1487 - 1492

PubMed ID

  • 7107458

International Standard Serial Number (ISSN)

  • 0161-7567

Digital Object Identifier (DOI)

  • 10.1152/jappl.1982.52.6.1487


  • eng

Conference Location

  • United States