Maximal Diffusing Capacity of the Lung for Carbon Monoxide*

Johnson, Robert L.; Taylor, Harold F.; Lawson, W H

doi:10.1172/jci105148

Cited by 36 publications

(6 citation statements)

References 18 publications

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“…Normal ranges for DMCO, Vc, and Qc at rest and exercise are from measurements made in 12 young normal subjects in our laboratory. These data have been previously reported in part (8).…”

Section: Methodssupporting

confidence: 91%

Exercise Limitation Following Extensive Pulmonary Resection*

DeGraff¹,

Taylor²,

Ord³

et al. 1965

J. Clin. Invest.

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“…Normal ranges for DMCO, Vc, and Qc at rest and exercise are from measurements made in 12 young normal subjects in our laboratory. These data have been previously reported in part (8).…”

Section: Methodssupporting

confidence: 91%

Exercise Limitation Following Extensive Pulmonary Resection*

DeGraff¹,

Taylor²,

Ord³

et al. 1965

J. Clin. Invest.

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“…As we said at the outset, some published observations suggest a linear increase of D lco up to a metabolic level representing about 40% of Vo2max, followed by a plateau-like stabilization [ [Johnson et al, 1965]. Also in our subjects, going through workloads representing at least 70% o f Voamax, the relation between D lco and V02 turned out to be linear, whether V02 was expressed as such or as percent of Vo2max (fig-5).…”

Section: Discussionsupporting

confidence: 65%

Correlations between Lung-Transfer Factor, Ventilation, and Cardiac Output during Exercise

Rampulla¹,

Marconi²,

Beulcke³

et al. 1976

Respiration

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In nine healthy and young subject of either sex, undergoing three or four rounds of muscular exercise of increasing severity on a bicycle ergometer, the authors investigated the behavior of the lung transfer factor (DL_CO), pulmonary ventilation (V), alveolar ventilation (Va), and cardiac output (Q). In all instances they found a positive linear correlation between DL_CO and oxygen consumption (VO₂), at least up to 70 % of maximum oxygen consumption (VO_2max) (r = 0.935; p < 0.001). Dl_CO was found to increase linearly as a function of increasing V (r = 0.898; p < 0.001) and even more so of increasing Va (r = 0.919; p < 0.001). Also the relationship between Dl_CO and Q appeared linear in all subjects (r = 0.926; p < 0.001). On the other hand, individual DL_CO values showed considerable scatter at equal VO₂, V, V_A, and Q values. Among the factors responsible for the increase of DL_CO during muscular exercise, in addition to increased ventilation and cardiac output, the authors suggest the possible role of the greater desaturation of mixed venous blood and variations of hemoglobin affinity for CO.

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“…The difference found with position at rest was abolished by exercise (43). The increase in the steady-state diffusing capacity with exercise has been shown to be virtually completely due to changes in the pulmonary capillary volume rather than in the membrane component (44); and Johnson and associates have shown by use of the single breath diffusing capacity that the increase in pulmonary capillary blood volume with maximal exercise is of the order of twofold (45).…”

Section: Discussionmentioning

confidence: 99%

Indicator dilution measurements of extravascular water in the lungs

Goresky¹,

Cronin²,

wangel³

1969

J. Clin. Invest.

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A B S T R A C T Multiple indicator dilution studies of the pulmonary circulation were carried out in conscious, resting and exercising, and anesthetized dogs under conditions where there was no pulmonary edema. Labeled red cells, water, and albumin were injected together into the pulmonary artery, and effluent dilution patterns were obtained from the descending thoracic aorta. The product of the mean transit time differences between labeled water and red cells, and the pulmonary water flow was used to estimate extravascular parenchymatous water; and this was expressed as a proportion of the water content of the blood-drained lung at postmortem examination. These estimates of the proportional water content were found to increase with flow, and to approach an asymptotic value. Reconsideration of the flow patterns in capillaries, however, led to the postulate that extravascular water should be calculated, utilizing as the appropriate vascular reference a substance that uniformly labels the water in red cells and plasma, and which is confined to the circulation, rather than a tracer that only labels red cells. The mean transit time of this substance is approximated by the sum of the mean transit times of labeled red cells and albumin, each weighted according to the proportion of the water content of blood present in that phase. The values for lung water content so computed also increased with flow, and appeared to approach an asymptote that corresponded to approximately two-thirds of the wet lung weight. The estimated values for the water space after pentobarbital anesthesia corresponded to the lower values obtained in the resting conscious animals. When the anesthetized animals were also bled, the estimated water space was disproportionately large, in relation to the previous values. These experimental results support the hypothesis that dilutional This work was presented in part at the 51st Annual

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Maximal Diffusing Capacity of the Lung for Carbon Monoxide*

Cited by 36 publications

References 18 publications

Exercise Limitation Following Extensive Pulmonary Resection*

Exercise Limitation Following Extensive Pulmonary Resection*

Correlations between Lung-Transfer Factor, Ventilation, and Cardiac Output during Exercise

Indicator dilution measurements of extravascular water in the lungs

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