Normal values for single exhalation diffusing capacity and pulmonary capillary blood flow in sitting, supine positions, and during mild exercise.

Journal Article (Journal Article)

Previous approaches to the measurements of pulmonary diffusing capacity (DL) and pulmonary capillary blood flow (QC) utilized either the rebreathing or the single inhalation technique in conjunction with radioisotope gas and mass spectrometry. In the present study, we utilized a newly developed rapid infrared analyzer in conjunction with the slow single exhalation technique on 100 healthy volunteers to establish normal values for DL and QC under sitting, supine, and exercise conditions. The exercise level was determined by a target heart rate: HRex = ([HRmax - HRrest]/3) + HRrest. Prediction equations based on regressions on age, sex, height, or weight were then computed for sitting, supine, and exercise values. We found that mean DL and QC increased by approximately 12 percent and 8 percent, respectively, from sitting to supine posture, and by approximately 30 percent and 100 percent, respectively, from sitting (rest) to mild exercise. These results provided a database for further studies in the single exhalation method in various clinical settings.

Full Text

Duke Authors

Cited Authors

  • Huang, YC; Helms, MJ; MacIntyre, NR

Published Date

  • February 1994

Published In

Volume / Issue

  • 105 / 2

Start / End Page

  • 501 - 508

PubMed ID

  • 8306754

International Standard Serial Number (ISSN)

  • 0012-3692

Digital Object Identifier (DOI)

  • 10.1378/chest.105.2.501


  • eng

Conference Location

  • United States