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Semin Respir Crit Care Med 2023; 44(05): 584-593
DOI: 10.1055/s-0043-1771161
Review Article

Blood Gas Transport: Implications for O2 and CO2 Exchange in Lungs and Tissues

Peter D. Wagner
1   Department of Medicine, University of California San Diego, La Jolla, California
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Abstract

The well-known ways in which O2 and CO2 (and other gases) are carried in the blood were presented in the preceding chapter. However, what the many available texts about O2 and CO2 transport do not emphasize is why knowing how gases are carried in blood matters, and this second, companion, article specifically addresses that critical aspect of gas exchange physiology. During gas exchange, both at the lungs and in the peripheral tissues, it is the shapes and the slopes of the O2 and CO2 binding curves that explain almost all of the behaviors of each gas and the quantitative differences observed between them. This conclusion is derived from first principle considerations of the gas exchange processes. Dissociation curve shape and slope differences explain most of the differences between O2 and CO2 in both diffusive exchange in the lungs and tissues and convective exchange/transport in, and between, the lungs and tissues. In fact, each of the chapters in this volume describes physiological behavior that depends more or less directly on the dissociation curves of O2 and CO2.

Keywords

inert gases - solubility - dissociation curves - diffusive gas exchange - convective gas transport - O2–CO2 interactions


Publication History

Article published online:
11 August 2023

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  • References

  • 1 Weibel ER. The Pathway for Oxygen: Structure and Function in the Mammalian Respiratory System. Cambridge Mass: Harvard University Press; 1984
    Google Scholar
  • 2 Piiper J, Scheid P. Blood-gas equilibration in the lungs. In: J.B W. ed. Pulmonary Gas Exchange Volume 1. Ventilation, Blood Flow and Diffusion. new York, NY: Academic press; 1980: 131-173
    Google Scholar
  • 3 Piiper J, Scheid P. Model for capillary-alveolar equilibration with special reference to O2 uptake in hypoxia. Respir Physiol 1981; 46 (03) 193-208
    CrossrefPubMedGoogle Scholar
  • 4 Piiper J, Scheid P. Comparison of diffusion and perfusion limitations in alveolar gas exchange. Respir Physiol 1983; 51 (03) 287-290
    CrossrefPubMedGoogle Scholar
  • 5 Piiper J, Scheid P. Diffusion limitation of O2 supply to tissue in homogeneous and heterogeneous models. Respir Physiol 1991; 85 (01) 127-136
    CrossrefPubMedGoogle Scholar
  • 6 Piiper J, Scheid P. Modeling oxygen availability to exercising muscle. Respir Physiol 1999; 118 (2-3): 95-101
    CrossrefPubMedGoogle Scholar
  • 7 Dempsey JA, Wagner PD. Exercise-induced arterial hypoxemia. J Appl Physiol 1999; 87 (06) 1997-2006
    CrossrefPubMedGoogle Scholar
  • 8 Wagner PD, Gale GE, Moon RE, Torre-Bueno JR, Stolp BW, Saltzman HA. Pulmonary gas exchange in humans exercising at sea level and simulated altitude. J Appl Physiol (1985) 1986; 61 (01) 260-270
    CrossrefPubMedGoogle Scholar
  • 9 Richardson RS, Noyszewski EA, Kendrick KF, Leigh JS, Wagner PD. Myoglobin O2 desaturation during exercise. Evidence of limited O2 transport. J Clin Invest 1995; 96 (04) 1916-1926
    CrossrefPubMedGoogle Scholar
  • 10 Andersen P, Saltin B. Maximal perfusion of skeletal muscle in man. J Physiol 1985; 366 (01) 233-249
    CrossrefPubMedGoogle Scholar
  • 11 Richardson RS, Grassi B, Gavin TP. et al. Evidence of O2 supply-dependent VO2 max in the exercise-trained human quadriceps. J Appl Physiol 1999; 86 (03) 1048-1053
    CrossrefPubMedGoogle Scholar
  • 12 Roca J, Hogan MC, Story D. et al. Evidence for tissue diffusion limitation of VO2max in normal humans. J Appl Physiol (1985) 1989; 67 (01) 291-299
    CrossrefPubMedGoogle Scholar
  • 13 Schmidt U. The solubility of carbon monoxide and hydrogen in water and sea-water at partial pressures of about 10-5 atmospheres. Tellus 1979; 31 (01) 68-74
    PubMedGoogle Scholar
  • 14 Rahn H, Fenn WO. Graphical Analysis of the Respiratory Gas Exchange. Bethesda, MD: American Physiological Society; 1955
    Google Scholar
  • 15 Riley RL, Cournand A. Analysis of factors affecting partial pressures of oxygen and carbon dioxide in gas and blood of lungs; theory. J Appl Physiol 1951; 4 (02) 77-101
    CrossrefPubMedGoogle Scholar
  • 16 Riley RL, Cournand A. Ideal alveolar air and the analysis of ventilation-perfusion relationships in the lungs. J Appl Physiol 1949; 1 (12) 825-847
    CrossrefPubMedGoogle Scholar
  • 17 Wagner PD, Malhotra A, Prisk GK. Using pulmonary gas exchange to estimate shunt and deadspace in lung disease: theoretical approach and practical basis. J Appl Physiol (1985) 2022; 132 (04) 1104-1113
    CrossrefPubMedGoogle Scholar
  • 18 Vogiatzis I, Habazettl H, Louvaris Z. et al. A method for assessing heterogeneity of blood flow and metabolism in exercising normal human muscle by near-infrared spectroscopy. J Appl Physiol (1985) 2015; 118 (06) 783-793
    CrossrefPubMedGoogle Scholar