JoVE Logo
Faculty Resource Center

Sign In

Summary

Abstract

Introduction

Protocol

Representative Results

Discussion

Acknowledgements

Materials

References

Medicine

Combining Volumetric Capnography And Barometric Plethysmography To Measure The Lung Structure-function Relationship

Published: January 8th, 2019

DOI:

10.3791/58238

1Department of Health and Human Physiology, Department of Internal Medicine, University of Iowa, 2Pulmonary, Critical Care and Occupational Medicine Division, University of Iowa, 3Hematology, Oncology and Bone Marrow Transplant Division, University of Iowa, 4Institute for Clinical and Translational Science and Stead Family Department of Pediatrics, University of Iowa

Here, we describe two measures of pulmonary function – barometric plethysmography, which allows the measurement of lung volume, and volumetric capnography, a tool to measure the anatomic dead space and airways uniformity. These techniques may be used independently or combined to assess airways function at different lung volumes.

Tools to measure lung and airways volume are critical for pulmonary researchers interested in evaluating the impact of disease or novel therapies on the lung. Barometric plethysmography is a classic technique to evaluate the lung volume with a long history of clinical use. Volumetric capnography utilizes the profile of exhaled carbon dioxide to determine the volume of the conducting airways, or dead space, and provides an index of airways homogeneity. These techniques may be used independently, or in combination to evaluate the dependence of airways volume and homogeneity on lung volume. This paper provides detailed technical instructions to replicate these techniques and our representative data demonstrates that the airways volume and homogeneity are highly correlated to lung volume. We also provide a macro for the analysis of capnographic data, which can be modified or adapted to fit different experimental designs. The advantage of these measures is that their advantages and limitations are supported by decades of experimental data, and they can be made repeatedly in the same subject without expensive imaging equipment or technically advanced analysis algorithms. These methods may be particularly useful for investigators interested in perturbations that change both the functional residual capacity of the lung and airways volume.

Gas washout techniques have been used for decades to provide important information about the structure and uniformity of the airway tree. The lung is classically described as having two compartments – a conducting zone that is comprised of the anatomic dead space and the respiratory zone where gas exchange occurs in the alveoli. The conducting airways are termed as “dead space” because they do not participate in the exchange of oxygen and carbon dioxide. In the single breath gas washout method, the concentration profile of an exhaled gas can be used to determine the volume of the anatomic dead space and to derive information about the uniformity of v....

Log in or to access full content. Learn more about your institution’s access to JoVE content here

This protocol has been previously approved by and follows the guidelines set by the University of Iowa Institutional Review Board. Data shown were collected as part of a project approved by the Institutional Review Board at the University of Iowa. Participants gave informed consent and the studies were performed in accordance with the Declaration of Helsinki.

1. Equipment

  1. Check the equipment table to verify that all required equipment is available. Double check the configuration us.......

Log in or to access full content. Learn more about your institution’s access to JoVE content here

Representative plethysmography results are given in Figure 4. This participant required four attempts in order to collect three FRC values with <5% variability from the mean.%Ref reflects the percent of the predicted value for each variable based on population regression equations that take into account sex, age, race, height and weight

Figure 1 (top) shows a repres.......

Log in or to access full content. Learn more about your institution’s access to JoVE content here

Here, a protocol for the measurement of VD and airways homogeneity (slope) is provided. These measurements can be made at FRC, or as a function of lung volume. Measuring FRC before the start of the experiment and after a perturbation allows VD and slope to be plotted as a function of lung volume and may provide useful information about the structure-function relationship of the lung that is not obtained from capnography at FRC alone.

Airways volume and high-resolution str.......

Log in or to access full content. Learn more about your institution’s access to JoVE content here

This work was funded by the Departments of Health and Human Physiology and Internal Medicine at the University of Iowa. This work was also supported by the Old Gold Fellowship (Bates) and Grant IRG-15-176-40 from the American Cancer Society, administered through The Holden Comprehensive Cancer Center at The University of Iowa (Bates)

....

Log in or to access full content. Learn more about your institution’s access to JoVE content here

Name Company Catalog Number Comments
Computer with dual monitor Dell Instruments
PowerLab 8/35* AD Instruments PL3508
LabChart Data Acquisition Software* AD Instruments Version 8
Gemini Respiratory Gas Analyzer* (upgraded option) CWE, Inc GEMINI 14-10000 *indicates that part is available in the Exercise Physiology package from AD Instruments
Heated Pneumotach with Heater Controller* (upgraded option) Hans Rudolph, Inc MLT3813H-V
3L Calibration Syringe Vitalograph 36020
Nose Clip* VacuMed Snuffer 1008
Pulse Transducer* AD Instruments TN1012/ST
Barometer Fischer Scientific 15-078-198
Flanged Mouthpiece* AD Instruments MLA1026
Nafion drying tube with three-way stopcock* AD Instruments MLA0343
Desiccant cartridge (optional for humid environments)* AD Instruments MLA6024
Resistor Hans Rudolph, Inc 7100 R5
Flow head adapters* AD Instruments MLA1081
Modified Tubing Adapter (optional) AD Instruments SP0145
Two way non-rebreather valve (optional)* AD Instruments SP0146
Plethysmograph Vyaire V62J
High Purity Helium Gas Praxair He 4.8
6% CO2 and 16% O2 Calibration Gas Praxair Custom
Microsoft Excel Microsoft Office 365

  1. Robinson, P. D., et al. Consensus statement for inert gas washout measurement using multiple- and single- breath tests. European Respiratory Journal. 41 (3), 507-522 (2013).
  2. Verbanck, S., Paiva, M. Gas mixing in the airways and airspaces. Comprehensive Physiology. 1 (2), 809-834 (2011).
  3. Bates, M. L., et al. Pulmonary function responses to ozone in smokers with a limited smoking history. Toxicology and Applied Pharmacology. 278 (1), 85-90 (2014).
  4. Bates, M. L., Brenza, T. M., Ben-Jebria, A., Bascom, R., Ultman, J. S. Longitudinal distribution of ozone absorption in the lung: comparison of cigarette smokers and nonsmokers. Toxicology and Applied Pharmacology. 236 (3), 270-275 (2009).
  5. Reeser, W. H., et al. Uptake of ozone in human lungs and its relationship to local physiological response. Inhalation Toxicology. 17 (13), 699-707 (2005).
  6. Taylor, A. B., Lee, G. M., Nellore, K., Ben-Jebria, A., Ultman, J. S. Changes in the carbon dioxide expirogram in response to ozone exposure. Toxicology and Applied Pharmacology. 213 (1), 1-9 (2006).
  7. Baker, L. G., Ultman, J. S., Rhoades, R. A. Simultaneous gas flow and diffusion in a symmetric airway system: a mathematical model. Respiration Physiology. 21 (1), 119-138 (1974).
  8. Fowler, W. S. Lung Function Studies. II. The Respiratory Dead Space. American Journal of Physiology-Legacy Content. 154 (3), 405-416 (1948).
  9. Eberlein, M., et al. Supranormal Expiratory Airflow after Bilateral Lung Transplantation Is Associated with Improved Survival. American Journal of Respiratory and Critical Care Medicine. 183 (1), 79-87 (2011).
  10. Eberlein, M., Schmidt, G. A., Brower, R. G. Chest wall strapping. An old physiology experiment with new relevance to small airways diseases. Annals of the American Thoracic Society. 11 (8), 1258-1266 (2014).
  11. Taher, H., et al. Chest wall strapping increases expiratory airflow and detectable airway segments in computer tomographic scans of normal and obstructed lungs. Journal of Applied Physiology. , (2017).
  12. Verscheure, S., Massion, P. B., Verschuren, F., Damas, P., Magder, S. Volumetric capnography: lessons from the past and current clinical applications. Critical Care. 20 (1), 184 (2016).
  13. Suarez-Sipmann, F., Bohm, S. H., Tusman, G. Volumetric capnography: the time has come. Current Opinion in Critical Care. 20 (3), 333-339 (2014).
  14. Wanger, J., et al. Standardisation of the measurement of lung volumes. European Respiratory Journal. 26 (3), 511-522 (2005).
  15. Culver, B. H., et al. Recommendations for a Standardized Pulmonary Function Report. An Official American Thoracic Society Technical Statement. American Journal of Respiratory and Critical Care Medicine. 196 (11), 1463-1472 (2017).
  16. Goldman, H. I., Becklake, M. R. Respiratory function tests; normal values at median altitudes and the prediction of normal results. Am Rev Tuberc. 79 (4), 457-467 (1959).
  17. Shim, S. S., et al. Lumen area change (Delta Lumen) between inspiratory and expiratory multidetector computed tomography as a measure of severe outcomes in asthmatic patients. J The Journal of Allergy and Clinical. , (2018).
  18. Smith, B. M., et al. Human airway branch variation and chronic obstructive pulmonary disease. Proceedings of the National Academy of Sciences of the United States of America. 115 (5), E974-E981 (2018).
  19. Farmery, A. D. Volumetric Capnography and Lung Growth in Children - a Simple-Model Validated. Anesthesiology. 83 (6), 1377-1379 (1995).
  20. Scherer, P. W., Neufeld, G. R., Aukburg, S. J., Hess, G. D. Measurement of Effective Peripheral Bronchial Cross-Section from Single-Breath Gas Washout. Journal of Biomechanical Engineering-Transactions of the Asme. 105 (3), 290-293 (1983).
  21. Sinha, P., Soni, N. Comparison of volumetric capnography and mixed expired gas methods to calculate physiological dead space in mechanically ventilated ICU patients. Intensive Care Medicine. 38 (10), 1712-1717 (2012).
  22. Bourgoin, P., et al. Assessment of Bohr and Enghoff Dead Space Equations in Mechanically Ventilated Children. Respiratory Care. 62 (4), 468-474 (2017).

This article has been published

Video Coming Soon

JoVE Logo

Privacy

Terms of Use

Policies

Research

Education

ABOUT JoVE

Copyright © 2024 MyJoVE Corporation. All rights reserved