False-Low Carbon Monoxide Diffusing Capacity Measurement After General Anesthesia

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.

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Measurement of Single-Breath Diffusing Capacity of the Lungs for Carbon Monoxide: new standards of European Respiratory Society and American Thoracic Society (рart 2)

Russian Pulmonology ◽

10.18093/0869-0189-2019-29-3-269-291 ◽

2019 ◽

Vol 29 (3) ◽

pp. 269-291

Author(s):

Article Editorial

Keyword(s):

Carbon Monoxide ◽

Expert Opinion ◽

Transfer Factor ◽

American Thoracic Society ◽

Diffusing Capacity ◽

Capacity Measurement ◽

European Respiratory Society ◽

Technical Standards ◽

Single Breath ◽

Published Evidence

This document is updated technical standards of European Respiratory Society (ERS) and American Thoracic Society (ATS) for single-breath carbon monoxide diffusing capacity measurement. The previous version of this document was published in 2005. Both terms used to describe the uptake of carbon monoxide in the lungs, DLCO (diffusing capacity) and TLCO (transfer factor), are equally valid, but the term DLCO is used in this document. The document was developed by joint ATS/ERS taskforce and was based on a survey of published evidence. Expert opinion was used for issues for which evidence was not available or was insufficient. Principal changes in the technical standards are related to new systems with rapidly responding gas analyzers for carbon monoxide. Additional materials are available at erj.ersjournals.com.Adopted from: Graham B.L., Brusasco V., Burgos F., Cooper B.G., Jensen R., Kendrick A., MacIntyre N.R., Thompson B.R., Wanger J. 2017 ERS/ATS standards for single-breath carbon monoxide uptake in the lung. Eur. Respir. J. 2017; 49 (1): pii: 1600016. DOI: 10.1183/13993003.00016-2016.

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Measurement of Single-Breath Diffusing Capacity of the Lungs for Carbon Monoxide: new standards of European Respiratory Society and American Thoracic Society (рart 1)

Russian Pulmonology ◽

10.18093/0869-0189-2019-29-2-149-158 ◽

2019 ◽

Vol 29 (2) ◽

pp. 149-158

Author(s):

Article Editorial

Keyword(s):

Carbon Monoxide ◽

Expert Opinion ◽

Transfer Factor ◽

American Thoracic Society ◽

Diffusing Capacity ◽

Capacity Measurement ◽

European Respiratory Society ◽

Technical Standards ◽

Single Breath ◽

Published Evidence

This document is updated technical standards of European Respiratory Society (ERS) and American Thoracic Society (ATS) for single-breath carbon monoxide diffusing capacity measurement. The previous version of this document was published in 2005. Both terms used to describe the uptake of carbon monoxide in the lungs, DLCO (diffusing capacity) and TLCO (transfer factor), are equally valid, but the term DLCO is used in this document. The document was developed by joint ATS/ERS taskforce and was based on a survey of published evidence. Expert opinion was used for issues for which evidence was not available or was insufficient. Principal changes in the technical standards are related to new systems with rapidly responding gas analyzers for carbon monoxide. Additional materials are available at erj.ersjournals.com.

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Reduced exercise tolerance in mild chronic obstructive pulmonary disease: The contribution of combined abnormalities of diffusing capacity for carbon monoxide and ventilatory efficiency

Respirology ◽

10.1111/resp.14045 ◽

2021 ◽

Author(s):

Devin B. Phillips ◽

Matthew D. James ◽

Amany F. Elbehairy ◽

Kathryn M. Milne ◽

Sandra G. Vincent ◽

...

Keyword(s):

Chronic Obstructive Pulmonary Disease ◽

Carbon Monoxide ◽

Pulmonary Disease ◽

Exercise Tolerance ◽

Chronic Obstructive ◽

Diffusing Capacity ◽

Obstructive Pulmonary Disease ◽

Ventilatory Efficiency

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Nonlinear increases in diffusing capacity during exercise by seated and supine subjects

Journal of Applied Physiology ◽

10.1152/jappl.1981.51.4.858 ◽

1981 ◽

Vol 51 (4) ◽

pp. 858-863 ◽

Cited By ~ 31

Author(s):

D. L. Stokes ◽

N. R. MacIntyre ◽

J. A. Nadel

Keyword(s):

Carbon Monoxide ◽

Oxygen Consumption ◽

Healthy Subjects ◽

Vital Capacity ◽

Maximal Exercise ◽

Sitting Position ◽

Diffusing Capacity ◽

Heavy Exercise ◽

Lung Volumes ◽

Rate Of Increase

To study the effects of exercise on pulmonary diffusing capacity, we measured the lungs' diffusing capacity for carbon monoxide (DLCO) during exhalation from 30 to 45% exhaled vital capacity in eight healthy subjects at rest and during exercise while both sitting and supine. We found that DLCO at these lung volumes in resting subjects was 26.3 +/- 3.2% (mean +/- SE) higher in the supine than in the sitting position (P less than 0.001). We also found that, in both positions, DLCO at these lung volumes increased significantly (P less than 0.001) with increasing exercise and approached similar values at maximal exercise. The pattern of increase in DLCO with an increase in oxygen consumption in both positions was curvilinear in that the rate of increase in DLCO during mild exercise was greater than the rate of increase in DLCO during heavy exercise (P = 0.02). Furthermore, in the supine position during exercise, it appeared that DLCO reached a physiological maximum.

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Carbon Monoxide and General Anesthesia: To the Editor

CHEST Journal ◽

10.1378/chest.110.5.1375-a ◽

1996 ◽

Vol 110 (5) ◽

pp. 1375

Author(s):

Robert Gilbert

Keyword(s):

Carbon Monoxide ◽

General Anesthesia

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Low-Carbon Monoxide Hydrogen by Sorption-Enhanced Reaction

International Journal of Chemical Reactor Engineering ◽

10.2202/1542-6580.1055 ◽

2003 ◽

Vol 1 (1) ◽

Cited By ~ 8

Author(s):

Douglas P Harrison ◽

Zhiyong Peng

Keyword(s):

Carbon Dioxide ◽

Carbon Monoxide ◽

Hydrogen Production ◽

Proton Exchange Membrane ◽

Primary Energy ◽

Proton Exchange ◽

Raw Material ◽

Impurity Level ◽

Low Carbon ◽

Enhanced Production

Hydrogen is an increasingly important chemical raw material and a probable future primary energy carrier. In many current and anticipated applications the carbon monoxide impurity level must be reduced to low-ppmv levels to avoid poisoning catalysts in downstream processes. Methanation is currently used to remove carbon monoxide in petroleum refining operations while preferential oxidation (PROX) is being developed for carbon monoxide control in fuel cells. Both approaches add an additional step to the multi-step hydrogen production process, and both inevitably result in hydrogen loss. The sorption enhanced process for hydrogen production, in which steam-methane reforming, water-gas shift, and carbon dioxide removal reactions occur simultaneously in the presence of a nickel-based reforming catalyst and a calcium-based carbon dioxide sorbent, is capable of producing high purity hydrogen containing minimal carbon monoxide in a single processing step. The process also has the potential for producing pure CO2 that is suitable for subsequent use or sequestration during the sorbent regeneration step. The current research on sorption-enhanced production of low-carbon monoxide hydrogen is an extension of previous research in this laboratory that proved the feasibility of producing 95+% hydrogen (dry basis), but without concern for the carbon monoxide concentration. This paper describes sorption-enhanced reaction conditions temperature, feed gas composition, and volumetric feed rate required to produce 95+% hydrogen containing low carbon monoxide concentrations suitable for direct use in, for example, a proton exchange membrane fuel cell.

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