DlCO measurements with gas chromatography

1962 ◽  
Vol 17 (6) ◽  
pp. 856-860 ◽  
Author(s):  
Josef R. Smith ◽  
Lyle H. Hamilton
Keyword(s):  
Gas Chromatography ◽  
Normal Subjects ◽  
Inert Gas ◽  
Breath Holding ◽  
Gas Mixture ◽  
Diffusing Capacity ◽  
Gas Chromatograph ◽  
Excellent Correlation ◽  
Pulmonary Diffusing Capacity ◽  
The Mean

A gas chromatograph has been used to analyze gases for the measurement of pulmonary diffusing capacity using the breath-holding technique. The gas mixture used for the measurement consisted of carbon monoxide in air with neon as the insoluble inert gas. The calculated DlCO was unaffected when sulphur hexafloride (SF6) or He was substituted for Ne in the mixture, but since CO and Ne could be most simply and rapidly analyzed, this combination was preferred for the gas mixture used to measure DlCO. The mean DlCO for ten normal subjects was 25.8 ± 4.2 ml/min mm Hg. These results were comparable to values reported in the literature when established methods of analysis were used. An excellent correlation was found between calculated DlCO and the clinical condition of patients with impaired pulmonary diffusing capacity. Submitted on February 14, 1962

Some effects of carbon dioxide on foreign gas uptake

1959 ◽  
Vol 14 (3) ◽  
pp. 333-338 ◽  
Author(s):  
Roy J. Shephard
Keyword(s):  
Carbon Dioxide ◽  
Normal Subjects ◽  
Minute Volume ◽  
Breath Holding ◽  
Analogue Computer ◽  
Diffusing Capacity ◽  
Gas Uptake ◽  
Consistent Change ◽  
The Mean ◽  
Nonuniform System

Partitional respirometry in normal subjects breathing 1-5% CO2 indicates a large increase of alveolar dead space, but in the steady state there is no consistent change of diffusing capacity or effective pulmonary blood flow. An apparent early decrease of diffusing capacity is probably an artefact due to difficulties in measuring acetylene uptake with a changing respiratory minute volume, and if Dco is measured by the breath-holding technique, carbon dioxide produces no immediate effect. Hypercapnic hyperventilation does not help in making acetylene uptake conform to a single exponential curve. The ventilatory efficiency indicated by partitional respirometry in a nonuniform system is dependent on both solubility of the test gases and the mean Va/Q ratio. An analogue computer for the solution of Va/Q problems is described. Submitted on August 18, 1958

Studies on the Pulmonary Diffusing Capacity by the Carbon Monoxide Breath Holding Technique: I. Normal Subjects

2009 ◽  
Vol 169 (5) ◽  
pp. 583-594 ◽  
Author(s):  
Haruo Kanagami ◽  
Toshiki Katsura ◽  
Koichiro Shiroishi ◽  
Kenji Baba ◽  
Toshiaki Ebina
Keyword(s):  
Carbon Monoxide ◽  
Normal Subjects ◽  
Breath Holding ◽  
Diffusing Capacity ◽  
Pulmonary Diffusing Capacity

Diffusing capacity of the lung in pulmonary emphysema

1964 ◽  
Vol 19 (5) ◽  
pp. 981-989 ◽  
Author(s):  
Stephen M. Ayres ◽  
Meta E. Buehler ◽  
Ruth G. Armstrong
Keyword(s):  
Gas Chromatography ◽  
Carbon Monoxide ◽  
Steady State ◽  
Body Size ◽  
Normal Subjects ◽  
Mean Value ◽  
Diffusing Capacity ◽  
Common Cause ◽  
Abnormal Distribution ◽  
The Mean

Steady-state CO and O2 methods for measuring pulmonary diffusing capacity may be affected by abnormal distribution of inspired gas relative to perfusion. These methods frequently fail to separate abnormalities in diffusion from abnormalities in distribution in patients with obstructive emphysema. A rebreathing CO method has been developed which, in theory, is less sensitive to inequalities in distribution. The DlCO by this method in 41 normal subjects averaged 20.8 ± 8.6 ml/min mm Hg and was closely correlated with body size and lung volume. Only 3 of 25 patients with obstructive emphysema had a DlCO less than the 95% confidence level although the mean value for all of the patients (16.8 ml/min mm Hg) was significantly lower than that of the normal group. It is concluded that loss of diffusing surface is not a common cause of oxyhemoglobin desaturation in obstructive emphysema. diffusion; carbon monoxide; ventilation-to-perfusion; gas chromatography Submitted on December 27, 1963

Change in diffusing capacity with blood flow in an improved isolated lung preparation

1963 ◽  
Vol 18 (2) ◽  
pp. 269-273 ◽  
Author(s):  
Edith Rosenberg
Keyword(s):  
Blood Flow ◽  
Left Atrial ◽  
Breath Holding ◽  
Gas Mixture ◽  
Diffusing Capacity ◽  
Gas Chromatograph ◽  
Blood Flows ◽  
Isolated Lung ◽  
Large Vessels ◽  
Lung Preparation

The isolated blood-perfused cat lung preparation has been improved by using large cannulas placed so as to minimize kinking of large vessels and by reducing the pressure produced by the perfusing pump by placing resistances between it and the lung. This improved preparation was capable of accepting blood flows up to 500 ml/min for 5–10 min and could be studied for 3–5 hr before deteriorating. The diffusing capacity for carbon monoxide, Dl, was measured at various blood flows up to 500 ml/min in seven isolated lung preparations improved as indicated. A breath-holding method using a gas mixture containing 2% SF6 and 0.3% CO was employed for measuring Dl. The test gas was analyzed on a gas chromatograph. Dl increased with blood flow in all the lungs studied. In four of them which were studied at constant left atrial pressure, Dl increased steadily by 10%/100 ml increase in blood flow throughout the range studied. Pulmonary vascular resistance decreased as Dl increased. Submitted on July 12, 1962

Relationship of increased breath-holding diffusing capacity to ventilation in exercise

1963 ◽  
Vol 18 (4) ◽  
pp. 794-797 ◽  
Author(s):  
Joseph C. Ross ◽  
Ronald W. Reinhart ◽  
John F. Boxell ◽  
Leroy H. King
Keyword(s):  
Steady State ◽  
Ventilation Rate ◽  
The Other ◽  
Breath Holding ◽  
Diffusing Capacity ◽  
Voluntary Hyperventilation ◽  
Pulmonary Diffusing Capacity ◽  
Pulmonary Capillaries ◽  
The Mean ◽  
Relationship Of

Pulmonary diffusing capacity (Dl), as measured by all techniques, increases with exercise possibly due to an increase in the volume of blood in pulmonary capillaries (Vc), but the mechanism for the latter is not known. Previous studies have indicated that the steady-state Dl can be increased by hyperventilation alone, enough possibly to account for the increase in Dl as measured by this method with exercise. On the other hand, breath-holding Dl is not increased by voluntary hyperventilation preceding the measurement. The present study was carried out to determine whether or not the increase in ventilation rate is a necessary part of a combination of factors which account for the rise in Dl during exercise. In this study breath-holding Dl was measured in five subjects. All of the five subjects studied had an increase in Dl during exercise when ventilation was voluntarily restrained to the resting level, and the mean increase was as great as the mean increase during the same amount of exercise with normal unrestricted breathing. The increase in Dl when breathing was restricted during exercise could not be accounted for by differences in alveolar volumes or by differences in alveolar O2 and CO2 tensions in the two situations. This study demonstrates that increase in ventilation preceding the measurement is not a determinant of the increase in breath-holding Dl with exercise Submitted on January 7, 1963

Influence of increased alveolar CO2 tension on pulmonary diffusing capacity for CO in man

1960 ◽  
Vol 15 (4) ◽  
pp. 543-549 ◽  
Author(s):  
J. Rankin ◽  
R. S. McNeill ◽  
R. E. Forster
Keyword(s):  
Systemic Blood Pressure ◽  
Repeated Measurements ◽  
Breath Holding ◽  
Gas Mixture ◽  
Diffusing Capacity ◽  
Pulmonary Diffusing Capacity ◽  
Pulmonary Capillary ◽  
Capillary Blood Volume ◽  
Pulmonary Capillary Blood ◽  
Capillary Bed

Since the pulmonary diffusing capacity for CO theoretically varies with changes in the size of the pulmonary capillary bed, it should be a useful tool for the investigation of the effects of CO2 on the pulmonary capillaries. Dl was measured during hypercapnia in nine normal resting subjects by the CO-helium breath-holding technique. a) When 10% CO2 was simply added to the inspired mixture used in the measurement of Dl, CO disappeared more rapidly from the lung. Dl was increased on the average only 5% after 10 seconds of breath holding. Pulmonary capillary blood volume (Vc) calculated by the method of Roughton and Forster was measured in two subjects and was increased approximately 46.5%. b) After the subject breathed a gas mixture containing 7.5% CO2 for 10 minutes, Dl was increased an average of 24% in all subjects and Vc was increased 112% in one subject studied. In five subjects repeated measurements of Dl, together with measurements of ventilation, systemic blood pressure, pulse rate and pulmonary blood flow in three of them, were made before, during and after a period of hypercapnia. After starting to breath the CO2-enriched gas mixture, Dl rose abruptly, reaching near maximal values in 2–5 minutes, while the other measurements of respiratory and circulatory phenomena continued to rise for 6–10 minutes, suggesting that the presumed increase in the pulmonary capillary bed was not dependent on the systemic respiratory and circulatory changes. Submitted on September 2, 1959

Gas chromatography in determination of pulmonary diffusing capacity

1964 ◽  
Vol 19 (3) ◽  
pp. 516-518 ◽  
Author(s):  
Arthur A. Sasahara ◽  
Virginia A. Burleson
Keyword(s):  
Gas Chromatography ◽  
Silica Gel ◽  
Molecular Sieves ◽  
Gas Flow ◽  
Peak Height ◽  
Breath Holding ◽  
Diffusing Capacity ◽  
Pulmonary Diffusing Capacity ◽  
Dual Column

Measurements of pulmonary diffusing capacity (Dco) were made using gas chromatography. The standard breath-holding technic was employed with the modification of using neon instead of helium for the dilution-reference gas. The two basic columns, silica gel, and 13 x molecular sieves were arranged in series on a dual-column chromatograph. All analyses were performed isothermally between 75–85 C with a carrier gas flow rate of 50–60 ml/min. Quantitation of the gas components was made simply and accurately by peak height measurements of the deflection curves on the chromatogram. The normal values for Dco by this method fall well within the range of normals determined by standard technics. The eminent suitability of gas chromatography for the determination of diffusing capacity derives from its simplicity, accuracy, and rapidity of gas analysis and its use of very small volumes of alveolar gas. breath-holding technic; neon; silica gel; 13 x molecular sieves; isothermic analysis; peak height measurements; dual-column chromatography Submitted on September 6, 1963

Single-breath CO diffusing capacity influenced by initial alveolar partial pressure of CO

1998 ◽  
Vol 275 (1) ◽  
pp. R339-R342
Author(s):  
Hartmut Heller ◽  
Klaus-Dieter Schuster
Keyword(s):  
Mass Spectrometry ◽  
Partial Pressure ◽  
Breath Holding ◽  
Gas Mixture ◽  
Residual Volume ◽  
Diffusing Capacity ◽  
Time Intervals ◽  
Single Breath ◽  
Identical Manner ◽  
End Tidal

The purpose of this study was to assess the influence of incorrect determinations of the initial alveolar partial pressure of carbon monoxide (CO) at the beginning of breath holding (Pia CO) on the pulmonary CO diffusing capacity of the lung (Dl CO). Single-breath maneuvers were performed on 14 anesthetized and artificially ventilated rabbits, using 0.2% CO in nitrogen as the indicator gas mixture. Inflation and deflation procedures were carried out in an identical manner on each animal, with inflation always starting from residual volume. End-tidal partial pressure of CO was determined by respiratory mass spectrometry and was used to calculate Dl CO values with the application of the three-equation ( method 1), as well as the conventional ( method 2), solution. In each rabbit, method 2 caused Dl CO values to be overestimated when compared with method 1, and this overestimation decreased with increasing time intervals of CO uptake. Because we were able to recalculate this deviation using Pia COvalues that were obtained by taking the diffusive removal of CO during inflation into account, we concluded that errors in estimating Pia CO by applying method 2 significantly contribute to the discrepancy between both methods.

Rate of uptake of carbon monoxide at different inspired concentrations in humans

1982 ◽  
Vol 52 (1) ◽  
pp. 109-113 ◽  
Author(s):  
H. A. Jones ◽  
J. C. Clark ◽  
E. E. Davies ◽  
R. E. Forster ◽  
J. M. Hughes
Keyword(s):  
Carbon Monoxide ◽  
Transport System ◽  
Human Lung ◽  
Normal Subjects ◽  
Facilitated Transport ◽  
Diffusing Capacity ◽  
Normal Human ◽  
The Mean ◽  
Co Concentrations

The rate of uptake of carbon monoxide (CO) in the lungs of normal subjects were measured at inspired concentrations of less than 1, 300, and 3,000 ppm (less than 0.0001–0.3%) using radioactive CO (11CO). In nine subjects the rate of uptake was monitored at the mouth during rebreathing. At inspired CO concentrations of approximately 1, 300, and 3,000 ppm and a mean alveolar O2 fraction of 0.15, the mean lung diffusing capacity was 25.8, 26.4, and 25.3 ml . min-1. Torr-1, respectively. In seven subjects the measurements were repeated after a period of O2 breathing, giving a mean alveolar O2 fraction of 0.78. The calculated membrane diffusing capacity was 31.9, 33.7, and 32.0 ml . min-1. Torr-1 at less than 1, 300, and 3,000 ppm inspired CO. We conclude that there is no difference in the rate of uptake of CO over the range of concentrations studied in these experiments. No evidence for the presence of a facilitated transport system for CO in the normal human lung was found.

Competitive inhibition of carbon monoxide transport: evidence against a carrier

1981 ◽  
Vol 50 (5) ◽  
pp. 1061-1064 ◽  
Author(s):  
D. Z. Rubin ◽  
D. Fujino ◽  
C. Mittman ◽  
S. M. Lewis
Keyword(s):  
Carbon Monoxide ◽  
Competitive Inhibition ◽  
Normal Adult ◽  
Gas Mixture ◽  
Diffusing Capacity ◽  
Constant Amount ◽  
Pulmonary Diffusing Capacity ◽  
Co Concentration ◽  
Carrier Molecule ◽  
Co Concentrations

The existence of a saturable carbon monoxide (CO) carrier in the lung remains controversial. The carrier hypothesis was invoked to explain data that indicated that pulmonary diffusing capacity for CO (DLCO) decreases with increasing CO concentration. To test this hypothesis, we measured DLCO in 14 normal adult subjects at three alveolar CO concentrations (60, 660, and 2,060 ppm). Each mixture contained a constant amount of labeled C18O (60 ppm) and a balance of unlabeled C16O. If a saturable carrier exists at increasing CO concentrations, the unlabeled CO would compete for most of the sites on the carrier molecule, effectively inhibiting the uptake of the labeled C18O. C18O diffusing capacities (mean +/- SD) for the three levels of CO were 34.9 +/- 5.6, 33.0 +/- 6.0, and 34.7 +/- 7.8. There were no significant differences (P greater than 0.2) among the three levels. In another group of subjects we repeated the study using a gas mixture containing 130 ppm C18O. No significant differences were found. As a result, we find no evidence to support a CO carrier hypothesis.

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