THE SINGLE BREATH DIFFUSING CAPACITY AND THE PERMEABILITY OF THE LUNGS OF NORMAL MAN

1963 ◽  
Vol 41 (1) ◽  
pp. 1283-1292
Author(s):  
Edith Rosenberg
Keyword(s):  
Molecular Sieve ◽  
The Other ◽  
Breath Holding ◽  
Diffusing Capacity ◽  
Alveolar Volume ◽  
Lung Volumes ◽  
Test Gas ◽  
Single Breath ◽  
Normal Man ◽  
Molecular Sieve Column

The single breath diffusing capacity for CO, DL, and the permeability of the lungs, K, were measured in six male and two female medical students at various lung volumes. The subjects rested 15 minutes before each test and the expired alveolar volume as well as breath-holding time and inspired volume were recorded on a spirogram. The test gas used consisted of 0.3% CO, 0.3% SF6, 20% O2, and the balance N2. The sample of alveolar gas expired after breath-holding was analyzed for CO and SF6 on a vapor fractometer using a 2-meter molecular sieve column. DL varied with the surface area of the subjects as well as with the alveolar volume at which the test was performed. K, on the other hand, was independent of the size of the subjects and decreased towards a constant value as lung volume became large. K should, therefore, be more reproducible than DL. The average permeability of the eight subjects used in this study was 0.0715 ml CO per second per ml of alveolar volume. In every experiment, alveolar volumes were also calculated from the SF6 dilution. These values, VD, were compared to alveolar volumes calculated from the maximum lung volumes, VA. For the males there was no measurable difference between alveolar volumes calculated by these two methods when 2 liters or more of test gas were inspired. It is suggested that the replacement of the measurement of DL in pulmonary function laboratories by an evaluation of K and VD may transform the single breath diffusing capacity test into a useful diagnostic tool.

THE SINGLE BREATH DIFFUSING CAPACITY AND THE PERMEABILITY OF THE LUNGS OF NORMAL MAN

1963 ◽  
Vol 41 (5) ◽  
pp. 1283-1292 ◽  
Author(s):  
Edith Rosenberg
Keyword(s):  
Molecular Sieve ◽  
The Other ◽  
Breath Holding ◽  
Diffusing Capacity ◽  
Alveolar Volume ◽  
Lung Volumes ◽  
Test Gas ◽  
Single Breath ◽  
Normal Man ◽  
Molecular Sieve Column

The single breath diffusing capacity for CO, DL, and the permeability of the lungs, K, were measured in six male and two female medical students at various lung volumes. The subjects rested 15 minutes before each test and the expired alveolar volume as well as breath-holding time and inspired volume were recorded on a spirogram. The test gas used consisted of 0.3% CO, 0.3% SF6, 20% O2, and the balance N2. The sample of alveolar gas expired after breath-holding was analyzed for CO and SF6 on a vapor fractometer using a 2-meter molecular sieve column. DL varied with the surface area of the subjects as well as with the alveolar volume at which the test was performed. K, on the other hand, was independent of the size of the subjects and decreased towards a constant value as lung volume became large. K should, therefore, be more reproducible than DL. The average permeability of the eight subjects used in this study was 0.0715 ml CO per second per ml of alveolar volume. In every experiment, alveolar volumes were also calculated from the SF6 dilution. These values, VD, were compared to alveolar volumes calculated from the maximum lung volumes, VA. For the males there was no measurable difference between alveolar volumes calculated by these two methods when 2 liters or more of test gas were inspired. It is suggested that the replacement of the measurement of DL in pulmonary function laboratories by an evaluation of K and VD may transform the single breath diffusing capacity test into a useful diagnostic tool.

Cardiogenic oscillations in He and SF6 expirograms during airway and venous loading

1990 ◽  
Vol 69 (3) ◽  
pp. 945-955 ◽  
Author(s):  
M. Meyer ◽  
S. M. Lewis ◽  
M. Mohr ◽  
H. Schulz ◽  
K. D. Schuster ◽  
...  
Keyword(s):  
Partial Pressure ◽  
Oscillation Amplitude ◽  
Alveolar Ventilation ◽  
Inert Gases ◽  
Breath Holding ◽  
Alveolar Volume ◽  
Test Gas ◽  
Single Breath ◽  
Pressure Profiles ◽  
Cardiogenic Oscillations

Cardiogenic oscillations in the expired partial pressure profiles of two inert gases (He and SF6) were monitored in seven anesthetized paralyzed mechanically ventilated dogs. He and SF6 were administered either intravenously by a membrane oxygenator and partial arteriovenous bypass [venous loading (VL)] or by washin into lung gas [airway loading (AL)]. The single-breath expirograms obtained during constant-flow expiration after inspiration of test gas-free air displayed distinct and regular cardiogenic oscillations. The relative oscillation amplitude (ROA), calculated as oscillation amplitude divided by mixed expired-inspired partial pressure difference, was in the range of 1-8%. The ROA for both He and SF6 was approximately 4.2 times higher in VL than in AL, which indicated that among lung units that emptied sequentially in the cardiac cycle, the effects of alveolar ventilation-perfusion (VA/Q) inequality were more pronounced than those of alveolar ventilation-alveolar volume (VA/VA) inequality. In AL, He and SF6 oscillations were 180 degrees out of phase compared with CO2 and O2 oscillations and with He and SF6 oscillations in VL, which suggests that regions with low VA/VA had high VA/Q and very low Q/VA. The ROA was practically unaffected by breath holding in both AL and VL, which indicates that there was little diffusive or convective (cardiogenic) mixing between the lung units that were responsible for cardiogenic oscillations. The ROA was consistently higher for He than for SF6, and the He-to-SF6 ratio was independent of route of test gas loading, averaging 1.6 in both AL and VL. This result may be explained by laminar Taylor dispersion, whereby oscillations generated in peripheral lung regions are dissipated in inverse proportion to diffusion coefficient during transit through the proximal (larger) airways.

scholarly journals Nonuniformity of Diffusing Capacity From Small Alveolar Gas Samples Is Increased in Smokers

1998 ◽  
Vol 5 (2) ◽  
pp. 101-108 ◽  
Author(s):  
DJ Cotton ◽  
JT Mink ◽  
BL Graham
Keyword(s):  
Vital Capacity ◽  
Phase Iii ◽  
Mixing Efficiency ◽  
Breath Holding ◽  
Diffusing Capacity ◽  
Test Gas ◽  
Ventilation Inhomogeneity ◽  
Single Breath ◽  
Lung Periphery ◽  
Physiological Tests

BACKGROUND: Although centrilobular emphysema, and small airway, interstitial and alveoli inflammation can be detected pathologically in the lungs of smokers with relatively well preserved lung function, these changes are difficult to assess using available physiological tests. Because submaximal single breath washout (SBWSM) manoeuvres improve the detection of abnormalities in ventilation inhomogeneity in the lung periphery in smokers compared with traditional vital capacity manoeuvres, SBWSMmanoeuvres were used in this study to measure temporal differences in diffusing capacity using a rapid response carbon monoxide analyzer.OBJECTIVE: To determine whether abnormalities in the lung periphery can be detected in smokers with normal forced expired volumes in 1 s using the three-equation diffusing capacity (DLcoSB-3EQ) among small alveolar gas samples and whether the abnormalities correlate with increases in peripheral ventilation inhomogeneity.PARTICIPANTS AND DESIGN: Cross-sectional study in 21 smokers and 21 nonsmokers all with normal forced exhaled flow rates.METHODS: Both smokers and nonsmokers performed SBWSMmanoeuvres consisting of slow inhalation of test gas from functional residual capacity to one-half inspiratory capacity with either 0 or 10 s of breath holding and slow exhalation to residual volume (RV). They also performed conventional vital capacity single breath (SBWVC) manoeuvres consisting of slow inhalation of test gas from RV to total lung capacity and, without breath holding, slow exhalation to RV. DLcoSB-3EQ was calculated from the total alveolar gas sample. DLcoSB-3EQ was also calculated from four equal sequential, simulated aliquots of the total alveolar gas sample. DLcoSB-3EQ values from the four alveolar samples were normalized by expressing each as a percentge of DLcoSB-3EQ from the entire alveolar gas sample. An index of variation (DI) among the small-sample DLcoSB-3EQ values was correlated with the normalized phase III helium slope (Sn) and the mixing efficiency (Emix).RESULTS: For SBWSM, DIwas increased in smokers at 0 s of breath holding compared with nonsmokers, and correlated with age, smoking pack-years and Sn. The decrease in DIwith breath holding was greater in smokers and correlated with the change in Sn with breath holding. For SBWVCmanoeuvres, there were no differences due to smoking in Sn or Emix, but DIwas increased in smokers and correlated with age and smoking pack-years, but not with Sn.CONCLUSIONS: For SBWSMmanoeuvres the increase in DIin smokers correlated with breath hold time-dependent increases in Sn, suggesting that the changes in DIreflected the same structural alterations that caused increases in peripheral ventilation inhomogeneity. For SBWVCmanoeuvres, the increase in DIin smokers was not associated with changes in ventilation inhomogeneity, suggesting that the effect of smoking on DIduring this manoeuvre was due to smoke-related changes in alveolar capillary diffusion, rather than due solely to alterations in the distribution of ventilation.

The effect of conductive ventilation heterogeneity on diffusing capacity measurement

2008 ◽  
Vol 104 (4) ◽  
pp. 1094-1100 ◽  
Author(s):  
Sylvia Verbanck ◽  
Daniel Schuermans ◽  
Sophie Van Malderen ◽  
Walter Vincken ◽  
Bruce Thompson
Keyword(s):  
Carbon Monoxide ◽  
Vital Capacity ◽  
Experimental Situation ◽  
Normal Subjects ◽  
Diffusing Capacity ◽  
Capacity Measurement ◽  
Alveolar Volume ◽  
Estimation Errors ◽  
Single Breath ◽  
Ventilation Heterogeneity

It has long been assumed that the ventilation heterogeneity associated with lung disease could, in itself, affect the measurement of carbon monoxide transfer factor. The aim of this study was to investigate the potential estimation errors of carbon monoxide diffusing capacity (DlCO) measurement that are specifically due to conductive ventilation heterogeneity, i.e., due to a combination of ventilation heterogeneity and flow asynchrony between lung units larger than acini. We induced conductive airway ventilation heterogeneity in 35 never-smoker normal subjects by histamine provocation and related the resulting changes in conductive ventilation heterogeneity (derived from the multiple-breath washout test) to corresponding changes in diffusing capacity, alveolar volume, and inspired vital capacity (derived from the single-breath DlCO method). Average conductive ventilation heterogeneity doubled ( P < 0.001), whereas DlCO decreased by 6% ( P < 0.001), with no correlation between individual data ( P > 0.1). Average inspired vital capacity and alveolar volume both decreased significantly by, respectively, 6 and 3%, and the individual changes in alveolar volume and in conductive ventilation heterogeneity were correlated ( r = −0.46; P = 0.006). These findings can be brought in agreement with recent modeling work, where specific ventilation heterogeneity resulting from different distributions of either inspired volume or end-expiratory lung volume have been shown to affect DlCO estimation errors in opposite ways. Even in the presence of flow asynchrony, these errors appear to largely cancel out in our experimental situation of histamine-induced conductive ventilation heterogeneity. Finally, we also predicted which alternative combination of specific ventilation heterogeneity and flow asynchrony could affect DlCO estimate in a more substantial fashion in diseased lungs, irrespective of any diffusion-dependent effects.

Diffusing capacity dependent on lung volume and age in normal subjects

1994 ◽  
Vol 76 (6) ◽  
pp. 2356-2363 ◽  
Author(s):  
H. Stam ◽  
V. Hrachovina ◽  
T. Stijnen ◽  
A. Versprille
Keyword(s):  
Reference Values ◽  
Linear Method ◽  
Hemoglobin Concentration ◽  
Normal Subjects ◽  
Random Coefficients ◽  
Diffusing Capacity ◽  
Alveolar Volume ◽  
Lung Volumes ◽  
Conversion Method ◽  
Older Subjects

In this study we determined reference values of total diffusing capacity of carbon monoxide (DLCO) and DLCO per liter alveolar volume (DLCO/VA) at total lung capacity (TLC) and at lung volumes below TLC in sitting position. In 55 healthy nonsmoking volunteers (20–85 yr old), we determined reference values at TLC level in which age was the only parameter. In a subgroup (n = 16) these references did not change by correction for normal variability in hemoglobin concentration. In all volunteers DLCO decreased and DLCO/VA increased with decreasing VA. The increase in DLCO/VA was linear and less in older subjects. We derived equations to calculate reference values of DLCO/VA for lung volumes at and below TLC with two methods: 1) “random coefficients linear” model, which calculates the reference values directly, and 2) a conversion method, which calculates DLCO/VA for lower VA levels from reference values at TLC. An advantage of the conversion method is the suitability of DLCO/VA reference values at TLC of other populations. A disadvantage is the greater standard deviation of these reference values compared with those obtained by the random coefficients linear method. DLCO can be found by multiplying DLCO/VA with VA.

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.

Influence of pressure suit inflation on pulmonary diffusing capacity in man

1962 ◽  
Vol 17 (2) ◽  
pp. 259-262 ◽  
Author(s):  
Joseph C. Ross ◽  
Glen D. Ley ◽  
Ronald F. Coburn ◽  
J. L. Eller ◽  
Robert E. Forster
Keyword(s):  
Valsalva Maneuver ◽  
Breath Holding ◽  
Entire Body ◽  
Costal Margin ◽  
Pulmonary Congestion ◽  
Diffusing Capacity ◽  
Thoracic Cage ◽  
Alveolar Volume ◽  
Air Trapping ◽  
Pulmonary Diffusing Capacity

Previous investigations of the effect of inflation of a pressure suit on pulmonary diffusing capacity (DL) have been reported from our two laboratories, one (Indianapolis) finding an increase and the other (Philadelphia) finding no change. The present investigation was carried out in Philadelphia, using some of the same subjects and pressure suits in order to reconcile the contradictory results. The earlier contradictory results were confirmed. The pressure suit used in the investigations at Philadelphia ( suit P)covered the entire body below the nipples, whereas the suit used in the investigations at Indianapolis( suit I) extended cephalad only as far as the costal margin. When suit P was inflated in the present study, DL again did not increase significantly in two subjects. However, when the upper part of the suit was folded down so that the thoracic cage was not covered, inflation of the suit did produce a significant increase in DL. Inflation of suit P when it covered the chest made it difficult for a subject not to perform a Valsalva maneuver during breath holding and caused more decrease in alveolar volume (Va) than when it was inflated in the folded-down position. In two subjects studied, we found no difference in air trapping with inflation of suit P in the two positions. The discrepancy between the results of the two earlier studies appears to have resulted from the different construction of the two pressure suits used. We conclude that pressure suit inflation in man will produce an increase in DL, presumably by means of pulmonary congestion. Submitted on September 22, 1961

Lung compliance, lung volumes, and single-breath diffusing capacity in dogs.

1972 ◽  
Vol 33 (6) ◽  
pp. 808-812 ◽  
Author(s):  
N E Robinson ◽  
J R Gillespie ◽  
J D Berry ◽  
A Simpson
Keyword(s):  
Lung Compliance ◽  
Diffusing Capacity ◽  
Lung Volumes ◽  
Single Breath
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