Abstract
In the course of studying gas exchange during partial liquid ventilation (PLV) in healthy and injured piglets, we noted a reversal in the profile of exhaled CO2 (PECO2) versus time. Rather than a positive slope, the CO2 expirogram often reached a peak early in expiration and fell toward the end of the breath. In addition to a change in sign, the absolute value of the slope was very large. The change in profile led us to question the generally accepted practice of using “end-tidal” PECO2 to represent average alveolar PACO2 during PLV. Given the steep rate of change of PECO2 over a breath, the use of a single point on the CO2 expirogram to represent alveolar gas during PLV seemed in error. We hypothesized that a combination of increased ventilation heterogeneity and diffusion limitation could account for the reversal in sign and exaggeration of the slopes. To further investigate this problem we explicitly measured PECO2 vs. exhaled volume in two additional experiments and compared these findings to 40 previously studied animals.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Similar content being viewed by others
References
Crank, J.Diffusion in a sphere. In: The Mathematics of Diffusion. Oxford: The Clarendon Press, 1970, chapt. 6.
Curtis, S. Perfluorocarbon-associated gas exchange: A hybrid approach to mechanical ventilation. Crit. Care Med. 19: 600–601, 1991.
Curtis, S. E. and J. T. Peek. Perfluorocarbon associated gas exchange in a canine model of acute lung injury. American Thoracic Society. A886, 1993.
Fuhrman, B. P., P. R. Paczan and M. DeFrancisis. Perfluorocarbon-associated gas exchange. Crit. Care Med. 19: 712–22, 1991.
Grønlund, J., E. R. Swenson, J. Ohlsson and M. P. Hlastala. Contribution of continuing gas exchange to phase III exhaled PCO2 and PO2 profiles. J. Appl. Physiol. 62: 2467–2476, 1987.
Leach, C. L., B. P. Fuhrman, F. C. Morin and M. G. Rath. Perfluorocarbon-associated gas exchange (partial liquid ventilation) in respiratory distress syndrome: A prospective, randomized, controlled study. Crit. Care Med. 21: 1270–1278, 1993.
Mates, E.A., J.C. Jackson, J. Hildebrandt, W.E. Truog, T.A. Standaert, and M.P. Hlastala. Respiratory gas exchange and inert gas retention during partial liquid ventilation. Oxygen Transport To Tissue XVI, in press.
Neufeld, G. R., S. Gobran, J. E. Baumgardner, S. J. Aukburg, M. Schreiner and P. W. Scherer. Diffusivity, respiratory rate and tidal volume influence inert gas expirograms. Respir. Physiol. 84: 31–47, 1991.
Olszowka, A.J., and L.E. Farhi. A system of digital computer subroutines for blood gas calculations. Respir. Physiol. 4: 270–280, 1968.
Otis, A. B., C. B. McKerrow, R. A. Bartlett, J. Mead, M. B. Mcllroy, N. J. Selverstone and E. P. Radford. Mechanical factors in distribution of pulmonary ventilation. J. Appl. Physiol. 8: 427–443, 1956.
Sargent, J. W. and R. J. Seffl. Properties of perfluorinated liquids. Fed. Proc. 29: 1699–1703, 1970.
Scherer, P. W., S. Gobran, S. J. Aukburg, J. E. Baumgardner, R. Bartkowski and G. R. Neufeld. Numerical and experimental study of steady-state CO2 and inert gas washout. J. Appl. Physiol. 64: 1022–1029, 1988.
Shaffer, T. H., C. A. Lowe, V. K. Bhutani and P. R. Douglas. Liquid ventilation: effects on pulmonary function in distressed meconium-stained lambs. Ped. Res. 18: 47–52, 1984.
Tarczy-Hornoch, P., J. Hildebrandt, T. Standaert, W. Lamm and J. C. Jackson. In-situ interfacial tension during liquid ventilation. Ped. Res. 35: 355a, 1994.
Tham, M. K., R. D. Walker and J. H. Modell. Diffusion coefficients of O2, N2, and CO2 in fluorinated ethers. J. Chem. Eng. Data. 18: 411–412, 1973.
Tutuncu, A. S., N. S. Faithfull and B. Lachmann. Intratracheal perfluorocarbon administration combined with mechanical ventilation in experimental respiratory distress syndrome: dose-dependent improvement of gas exchange. Crit. Care Med. 21: 962–969, 1993.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1996 Plenum Press, New York
About this chapter
Cite this chapter
Mates, E.A., Tarczy-Hornoch, P., Hildebrandt, J., Jackson, J.C., Hlastala, M.P. (1996). Negative Slope of Exhaled CO2 Profile. In: Ince, C., Kesecioglu, J., Telci, L., Akpir, K. (eds) Oxygen Transport to Tissue XVII. Advances in Experimental Medicine and Biology, vol 388. Springer, Boston, MA. https://doi.org/10.1007/978-1-4613-0333-6_75
Download citation
DOI: https://doi.org/10.1007/978-1-4613-0333-6_75
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4613-8002-3
Online ISBN: 978-1-4613-0333-6
eBook Packages: Springer Book Archive