scholarly journals Reference equations for pulmonary diffusing capacity of carbon monoxide and nitric oxide in adult Caucasians

2018 ◽  
Vol 52 (1) ◽  
pp. 1500677 ◽  
Author(s):  
Mathias Munkholm ◽  
Jacob Louis Marott ◽  
Lars Bjerre-Kristensen ◽  
Flemming Madsen ◽  
Ole Find Pedersen ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Carbon Monoxide ◽  
Hold Time ◽  
Specific Conductance ◽  
Breath Hold ◽  
Diffusing Capacity ◽  
Single Breath ◽  
Capillary Membrane ◽  
Reference Equations ◽  
Hb Concentration

The aim of this study was to determine reference equations for the combined measurement of diffusing capacity of the lung for carbon monoxide (CO) and nitric oxide (NO) (DLCONO). In addition, we wanted to appeal for consensus regarding methodology of the measurement including calculation of diffusing capacity of the alveolo-capillary membrane (Dm) and pulmonary capillary volume (Vc).DLCONO was measured in 282 healthy individuals aged 18–97 years using the single-breath technique and a breath-hold time of 5 s (true apnoea period). The following values were used: 1) specific conductance of nitric oxide (θNO)=4.5 mLNO·mLblood−1·min−1·mmHg−1; 2) ratio of diffusing capacity of the membrane for NO and CO (DmNO/DmCO)=1.97; and 3) 1/red cell CO conductance (1/θCO)=(1.30+0.0041·mean capillary oxygen pressure)·(14.6/Hb concentration in g·dL−1).Reference equations were established for the outcomes of DLCONO, including DLCO and DLNO and the calculated values Dm and Vc. Independent variables were age, sex, height and age squared.By providing new reference equations and by appealing for consensus regarding the methodology, we hope to provide a basis for future studies and clinical use of this novel and interesting method.

scholarly journals Standardisation and application of the single-breath determination of nitric oxide uptake in the lung

2017 ◽  
Vol 49 (2) ◽  
pp. 1600962 ◽  
Author(s):  
Gerald S. Zavorsky ◽  
Connie C.W. Hsia ◽  
J. Michael B. Hughes ◽  
Colin D.R. Borland ◽  
Hervé Guénard ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Hold Time ◽  
Haemoglobin Concentration ◽  
Specific Conductance ◽  
Breath Holding ◽  
Breath Hold ◽  
Diffusing Capacity ◽  
Detection Range ◽  
Single Breath ◽  
Alveolar Oxygen

Diffusing capacity of the lung for nitric oxide (DLNO), otherwise known as the transfer factor, was first measured in 1983. This document standardises the technique and application of single-breathDLNO. This panel agrees that 1) pulmonary function systems should allow for mixing and measurement of both nitric oxide (NO) and carbon monoxide (CO) gases directly from an inspiratory reservoir just before use, with expired concentrations measured from an alveolar “collection” or continuously sampledviarapid gas analysers; 2) breath-hold time should be 10 s with chemiluminescence NO analysers, or 4–6 s to accommodate the smaller detection range of the NO electrochemical cell; 3) inspired NO and oxygen concentrations should be 40–60 ppm and close to 21%, respectively; 4) the alveolar oxygen tension (PAO2) should be measured by sampling the expired gas; 5) a finite specific conductance in the blood for NO (θNO) should be assumed as 4.5 mL·min-1·mmHg-1·mL-1of blood; 6) the equation for 1/θCO should be (0.0062·PAO2+1.16)·(ideal haemoglobin/measured haemoglobin) based on breath-holdingPAO2and adjusted to an average haemoglobin concentration (male 14.6 g·dL−1, female 13.4 g·dL−1); 7) a membrane diffusing capacity ratio (DMNO/DMCO) should be 1.97, based on tissue diffusivity.

Effect of ventilation inhomogeneity on "intrabreath" measurements of diffusing capacity in normal subjects

1993 ◽  
Vol 75 (2) ◽  
pp. 927-932 ◽  
Author(s):  
D. J. Cotton ◽  
M. B. Prabhu ◽  
J. T. Mink ◽  
B. L. Graham
Keyword(s):  
Lung Volume ◽  
Hold Time ◽  
Normal Subjects ◽  
Phase Iii ◽  
Breath Hold ◽  
Diffusing Capacity ◽  
Ventilation Inhomogeneity ◽  
Single Breath ◽  
The Mean ◽  
And Diffusion

In normal seated subjects we increased single-breath ventilation inhomogeneity by changing both the preinspiratory lung volume and breath-hold time and examined the ensuing effects on two different techniques of measuring the diffusing capacity of the lung for carbon monoxide (DLCO). We measured the mean single-breath DLCO using the three-equation method (DLCOSB-3EQ) and also measured DLCO over discrete intervals during exhalation by the "intrabreath" method (DLCOexhaled). We assessed the distribution of ventilation using the normalized phase III slope for helium (SN). DLCOSB-3EQ was unaffected by preinspiratory lung volume and breath-hold time. DLCOexhaled increased with increasing preinspiratory lung volume and decreased with increasing breath-hold time. These changes correlated with the simultaneously observed changes in ventilation inhomogeneity as measured by SN (P < 0.01). We conclude that measurements of DLCOexhaled do not accurately reflect the mean DLCO. Intrabreath methods of measuring DLCO are based on the slope of the exhaled CO concentration curve, which is affected by both ventilation and diffusion inhomogeneities. Although DLCOexhaled may theoretically provide information about the distribution of CO uptake, the concomitant effects of ventilation nonuniformity on DLCOexhaled may mimic or mask the effects of diffusion nonuniformity.

Pulmonary diffusing capacities for oxygen-labeled CO2 and nitric oxide in rabbits

1998 ◽  
Vol 84 (2) ◽  
pp. 606-611 ◽  
Author(s):  
Hartmut Heller ◽  
Gabi Fuchs ◽  
Klaus-Dieter Schuster
Keyword(s):  
Nitric Oxide ◽  
Mass Spectrometry ◽  
Mean Value ◽  
Breath Holding ◽  
Breath Hold ◽  
Diffusing Capacity ◽  
Membrane Component ◽  
Single Breath ◽  
Partial Pressures

Heller, Hartmut, Gabi Fuchs, and Klaus-Dieter Schuster. Pulmonary diffusing capacities for oxygen-labeled CO2 and nitric oxide in rabbits. J. Appl. Physiol. 84(2): 606–611, 1998.—We determined the pulmonary diffusing capacity (Dl) for18O-labeled CO2(C18O2) and nitric oxide (NO) to estimate the membrane component of the respective gas conductances. Six anesthetized paralyzed rabbits were ventilated by a computerized ventilatory servo system. Single-breath maneuvers were automatically performed by inflating the lungs with gas mixtures containing 0.9% C18O2or 0.05% NO in nitrogen, with breath-holding periods ranging from 0 to 1 s for C18O2and from 2 to 8 s for NO. The alveolar partial pressures of C18O2and NO were determined by using respiratory mass spectrometry. Dl was calculated from gas exchange during inflation, breath hold, and deflation. We obtained values of 14.0 ± 1.1 and 2.2 ± 0.1 (mean value ± SD) ml ⋅ mmHg−1 ⋅ min−1for[Formula: see text]and Dl NO, respectively. The measured[Formula: see text]/Dl NOratio was one-half that of the theoretically predicted value according to Graham’s law (6.3 ± 0.5 vs. 12, respectively). Analyses of the several mechanisms influencing the determination of[Formula: see text]and Dl NOand their ratio are discussed. An underestimation of the membrane diffusing component for CO2 is considered the likely reason for the low[Formula: see text]/Dl NOratio obtained.

Measurement of single breath-hold carbon monoxide diffusing capacity in healthy infants and toddlers

2006 ◽  
Vol 41 (6) ◽  
pp. 544-550 ◽  
Author(s):  
Andres Castillo ◽  
Conrado J. Llapur ◽  
Tanya Martinez ◽  
Jeff Kisling ◽  
Tamica Williams-Nkomo ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Breath Hold ◽  
Diffusing Capacity ◽  
Infants And Toddlers ◽  
Single Breath ◽  
Single Breath Hold ◽  
Healthy Infants

scholarly journals Implementing the Three-Equation Method of Measuring Single Breath Carbon Monoxide Diffusing Capacity

1996 ◽  
Vol 3 (4) ◽  
pp. 247-257 ◽  
Author(s):  
Brian L Graham ◽  
Joseph T Mink ◽  
David J Cotton
Keyword(s):  
Carbon Monoxide ◽  
Lung Volume ◽  
Equation Method ◽  
Breath Holding ◽  
Breath Hold ◽  
Diffusing Capacity ◽  
Flow Rates ◽  
Single Breath ◽  
Conventional Methods ◽  
Made In

Conventional methods of measuring the single breath diffusing capacity of the lung for carbon monoxide (DLcoSB) are based on the Krogh equation, which is valid only during breath holding. Rigid standardization is used to approximate a pure breath hold manoeuvre, but variations in performing the manoeuvre cause errors in the measurement of DLcoSB. The authors previously described a method of measuring DLcoSBusing separate equations describing carbon monoxide uptake during each phase of the manoeuvre: inhalation, breath holding and exhalation. The method is manoeuvre-independent, uses all of the exhaled alveolar gas to improve estimates of mean DLcoSBand lung volume, and is more accurate and precise than conventional methods. A slow, submaximal, more physiological single breath manoeuvre can be used to measure DLcoSBin patients who cannot achieve the flow rates and breath hold times necessary for the standardized manoeuvre. The method was initially implemented using prototype equipment but commercial systems are now available that are capable of implementing this method. The authors describe how to implement the method and discuss considerations to be made in its use.

Effect of breath-hold time on DLCO(SB) in patients with airway obstruction

1985 ◽  
Vol 58 (4) ◽  
pp. 1319-1325 ◽  
Author(s):  
B. L. Graham ◽  
J. T. Mink ◽  
D. J. Cotton
Keyword(s):  
Hold Time ◽  
Phase Iii ◽  
Breath Holding ◽  
Breath Hold ◽  
Single Breath ◽  
Incomplete Mixing ◽  
Capillary Membrane ◽  
Phase Iii Slope ◽  
Alveolar Capillary ◽  
Short Breath

The single-breath diffusing capacity of the lung for CO [DLCO(SB)] is considered a measure of the conductance of CO across the alveolar-capillary membrane and its binding with hemoglobin. Although incomplete mixing of inspired gas with alveolar gas could theoretically influence overall diffusion, conventional calculations of DLCO(SB) spuriously overestimate DLCO(SB) during short breath-holding periods when incomplete mixing of gas within the lung might have the greatest effect. Using the three-equation method to calculate DLCO(SB) which analytically accounts for changes in breath-hold time, we found that DLCO(SB) did not change with breath-hold time in control subjects but increased with increasing breath-hold time in both patients with asthma and patients with emphysema. The increase in DLCO(SB) with increasing breath-hold time correlated with the phase III slope of the single-breath N2 washout curve. We suggest that in patients with ventilation maldistribution, DLCO(SB) may be decreased for the shorter breath-hold maneuvers because overall diffusion is limited by the reduced transport of CO from the inspired gas through the alveolar gas prior to alveolar-capillary gas exchange.

scholarly journals The need for race-specific reference equations for pulmonary diffusing capacity for nitric oxide

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Gerald Stanley Zavorsky ◽  
Ahmad Saleh Almamary ◽  
Mobarak Khalid Alqahtani ◽  
Shi Huh Samuel Shan ◽  
Douglas Shawn Gardenhire
Keyword(s):  
Nitric Oxide ◽  
Racial Differences ◽  
Breath Hold ◽  
Specific Reference ◽  
Regression Equations ◽  
Diffusing Capacity ◽  
Alveolar Volume ◽  
Pulmonary Diffusing Capacity ◽  
Pilot Data ◽  
Reference Equations

Abstract Background Few reference equations exist for healthy adults of various races for pulmonary diffusing capacity for nitric oxide (DLNO). The purpose of this study was to collect pilot data to demonstrate that race-specific reference equations are needed for DLNO. Methods African Americans (blacks) were chosen as the comparative racial group. In 2016, a total of 59 healthy black subjects (27 males and 32 females) were recruited to perform a full battery of pulmonary function tests. In the development of DLNO reference equations, a white reference sample (randomly drawn from a population) matched to the black sample for sex, age, and height was used. Multiple linear regression equations for DLNO, alveolar volume (VA), and pulmonary diffusing capacity for carbon monoxide (DLCO) using a 5–6 s breath-hold were developed. Results Our models demonstrated that sex, age2, race, and height explained 71% of the variance in DLNO and DLCO, with race accounting for approximately 5–10% of the total variance. After normalizing for sex, age2, and height, blacks had a 12.4 and 3.9 mL/min/mmHg lower DLNO and DLCO, respectively, compared to whites. The lower diffusing capacity values in blacks are due, in part, to their 0.6 L lower VA (controlling for sex and height). Conclusion The results of this pilot data reveal small but important and statistically significant racial differences in DLNO and DLCO in adults. Future reference equations should account for racial differences. If these differences are not accounted for, then the risk of falsely diagnosing lung disease increase in blacks when using reference equations for whites.

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.

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