Henderson M, Apthorp GH. Rapid method for estimation of carbon monoxide in blood. Brit Med J 1960: 2: 1853
“Each subject washed the nitrogen from his lungs by breathing 100% oxygen from a simple open circuit (Fig. 1) for a period of three minutes. At the end of this time he was instructed to take a maximum inspiration and hold his breath. The three-way tap (T) was then turned and exhaled through a carbon dioxide absorber, previously washed out with oxygen into an empty and rebreathed from this bag for a further three minutes. The contents of the bag were then analysed for oxygen by the Haldane method and for carbon monoxide, using an infra-red meter.”
From Johnson RL, Spicer WE, Bishop JM, Forster RE. Pulmonary capillary blood volume, flow and diffusing capacity during exercise. J Appl Physiol 1960; 15: 893-900
“Measurements were made as follows: after exhaling to residual volume, the subject went on the mouthpiece and rapidly inhaled a measured volume of the gas mixture from bag A. This breath was held for a measured time after which is was exhaled rapidly. The first liter of exhalate was allowed to clear the dead space, after which tap A was turned 90 degrees counter clockwise and an alveolar sample of a bout a liter was collected in bag B. t was not convenient to clamp this wide-mouthed sampling bag and remove it; therefore, the sample was aspirated into another removable bag C, in which it was sealed and set aside for later analysis.”
From Kreuzer F, Van Lookeren Campagne P. “Resting Pulmonary Diffusing Capacity for CO and O2 at Altitude”. J Appl Physiol 1965; 20: 519
The supine subjects rested for about a half an hour and then breathed, in varying sequence through a low-resistance valve, one of the following gas mixtures listed in Table 1, first without CO for some 10 min, and subsequently with 0.1% CO. In this way similar inspiratory O2 pressures were attained for the three levels of oxygenation at both altitudes (about 80, 150 and 400 mm Hg, respectively, with the following average alveolar PO2 in mm Hg: at sea level 46.5, 1.7.6 and 382; high altitude: 53.6, 117 and 365). After equilibration with the CO-free gas mixture the inspiratory circuit was switched to the corresponding CO-containing muxture (Fig. 1, stopcock A or B). On and one-half minutes were allowed for equilibration with 0.1% CO which is considered sufficient by most authors; aftere simultaneous washing out of spirometer and connections towards the end of this period, stopcocks C and D were turned to collect expired gas in a 9-liter spirometer with continuous recording of breaths during about a a half a minute, bringing total exposure to CO to some min per run.