Transit time of blood in lung capillary

Range during rest ~0.7: when cardiac output is maximal 0.3: in newborn infants 0.2 sec
Organism Human Homo sapiens
Reference Brahm J, Wimberley PD. Chloride and bicarbonate transport in fetal red cells. J Physiol. 1989 Dec419: 141-56. p.142 top paragraphPubMed ID2621626
Primary Source [1] Wagner, P. D. (1977). Diffusion and chemical reaction in pulmonary gas exchange. Physiological Reviews 57, 257-312. p.282 bottom paragraph [2] Hill, E., Power, G. G. & Longo, L. D. (1977). Kinetics of 02 and CO2 exchange. In Lung Biology and Health Series. Bioengineering Aspects of the Lung, vol. 3, ed. West, J. B., pp. 459-514. New York: Marcel Dekker.PubMed ID15292
Comments "The anion exchange system of red cells plays a central role in the transport of carbon dioxide from the tissues to the lungs by the blood. The presence of a transport system that mediates the obligatory exchange of bicarbonate for chloride, the so-called Hamburger shift, makes it possible to utilize the capacity of the blood to transport CO2 as bicarbonate. Considerations based upon studies of chloride and bicarbonate exchange at body temperature (Wieth & Brahm, 1980 Wieth, Andersen, Brahm, Bjerrum & Borders, 1982) suggest that in red cells from adults 90 % equilibration occurs within about 0.4 s. Hence, approximately 99 % equilibration is attained within the transit time of the blood in the capillary (close to 0.7 s during rest). However, the CO2 transporting capacity of blood is not exploited when the cardiac output is maximal under which conditions the transit time in the lung capillary may be reduced to as little as 0.3 s (primary source [1]). In newborn infants, however, the transit time for a red cell in the lung capillary may be even shorter, 0.2s, due to the incomplete development of the lungs of newborn infants (primary source [2])."
Entered by Uri M
ID 110883