Editing Diffusing capacity (section)

==History==

In one sense, it is remarkable that DL<sub>CO</sub> has retained such clinical utility.  The technique was invented to settle one of the great controversies of pulmonary physiology a century ago, namely the question of whether oxygen and the other gases were actively transported into and out of the blood by the lung, or whether gas molecules diffused passively.<ref>{{cite journal | author = Gjedde A | year = 2010 | title = Diffusive insights: on the disagreement of Christian Bohr and August Krogh | journal = Adv Physiol Educ | volume = 34 | issue = 4| pages = 174–185 | doi = 10.1152/advan.00092.2010 | pmid = 21098384 | s2cid = 31010852 }}</ref> Remarkable too is the fact that both sides used the technique to gain evidence for their respective hypotheses. To begin with, [[Christian Bohr]] invented the technique, using a protocol analogous to the steady state diffusion capacity for carbon monoxide, and concluded that oxygen was actively transported into the lung.  His student, [[August Krogh]] developed the single breath diffusion capacity technique along with his wife [[August Krogh|Marie]], and convincingly demonstrated that gasses diffuse passively,<ref>Krogh A. 1910 On the oxygen metabolism of the blood. Skand Arch Physiol 23: 193–199</ref><ref>Krogh A. 1910 On the mechanism of the gas-exchange in the lungs of the tortoise. Skand Arch Physiol 23: 200–216.</ref><ref>Krogh A. 1910 On the combination of hæmoglobin with mixtures of oxygen and carbonic acid. Skand Arch Physiol 23: 217–223.</ref><ref>Krogh A. 1910 Some experiments on the invasion of oxygen and carbonic oxide into water. Skand Arch Physiol 23: 224–235</ref><ref>Krogh A. 1910 On the mechanism of gas exchange in the lungs. Skand Arch Physiol 23: 248–278</ref><ref>Krogh A, Krogh M. 1910 On the tensions of gases in arterial blood. Skand Arch Physiol 23: 179–192.</ref><ref>Krogh A, Krogh M. 1910 Rate of diffusion into lungs of man. Skand Arch Physiol 23: 236–247</ref> a finding that led to the demonstration that capillaries in the blood were recruited into use as needed – a Nobel Prize–winning idea.<ref>{{Cite web | url=https://www.nobelprize.org/nobel_prizes/medicine/laureates/1920/krogh-bio.html | title=The Nobel Prize in Physiology or Medicine 1920}}</ref>