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Perez-Bogerd S, Van Muylem A, Zengin S, El Khloufi Y, Maufroy E, Faoro V, Malinovschi A, Michils A. LAMA improves tissue oxygenation more than LABA in patients with COPD. J Appl Physiol (1985) 2024; 137:154-165. [PMID: 38722752 DOI: 10.1152/japplphysiol.00467.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 04/11/2024] [Accepted: 05/01/2024] [Indexed: 07/13/2024] Open
Abstract
The effect of bronchodilators is mainly assessed with forced expiratory volume in 1 s (FEV1) in chronic obstructive pulmonary disease (COPD). Their impact on oxygenation and lung periphery is less known. Our objective was to compare the action of long-acting β2-agonists (LABA-olodaterol) and muscarinic antagonists (LAMA-tiotropium) on tissue oxygenation in COPD, considering their impact on proximal and peripheral ventilation as well as lung perfusion. FEV1, Helium slope (SHe) from a single-breath washout test (SHe decreases reflecting a peripheral ventilation improvement), frequency dependence of resistance (R5-R19), area under reactance (AX), lung capillary blood volume (Vc) from double diffusion (DLNO/DLCO), and transcutaneous oxygenation (TcO2) were measured before and 2 h post-LABA (day 1) and LAMA (day 3) in 30 patients with COPD (FEV1 54 ± 18% pred; GOLD A 31%/B 48%/E 21%) after 5-7 days of washout, respectively. We found that TcO2 increased more (P = 0.03) after LAMA (11 ± 12% from baseline, P < 001) compared with LABA (4 ± 11%, P = 0.06) despite a lower FEV1 increase (P = 0.03) and similar SHe (P = 0.98), AX (P = 0.63), and R5-R19 decreases (P = 0.37). TcO2 and SHe changes were negatively correlated (r = -0.47, P = 0.01) after LABA, not after LAMA (r = 0.10, P = 0.65). DLNO/DLCO decreased and Vc increased after LAMA (P = 0.04; P = 0.01, respectively) but not after LABA (P = 0.53; P = 0.24). In conclusion, LAMA significantly improved tissue oxygenation in patients with COPD, while only a trend was observed with LABA. The mechanisms involved may differ between both drugs: LABA increased peripheral ventilation, whereas LAMA increased lung capillary blood volume. Should oxygenation differences persist over time, LAMA could arguably become the first therapeutic choice in COPD.NEW & NOTEWORTHY Long-acting muscarinic antagonists (LAMAs) significantly improved tissue oxygenation in patients with COPD, while only a trend was observed with β2-agonists (LABAs). The mechanisms involved may differ between drugs: increased peripheral ventilation for LABA and likely lung capillary blood volume for LAMA. This could argue for LAMA as the first therapeutic choice in COPD.
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Affiliation(s)
- Silvia Perez-Bogerd
- Chest Department, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Alain Van Muylem
- Chest Department, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Selim Zengin
- Chest Department, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Yasmina El Khloufi
- Chest Department, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Emilie Maufroy
- Cardiopulmonary Exercise Laboratory, Faculty of Motorskill Science, Université Libre de Bruxelles, Brussels, Belgium
| | - Vitalie Faoro
- Cardiopulmonary Exercise Laboratory, Faculty of Motorskill Science, Université Libre de Bruxelles, Brussels, Belgium
| | - Andrei Malinovschi
- Department of Medical Sciences: Clinical Physiology, Uppsala University, Uppsala, Sweden
| | - Alain Michils
- Chest Department, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
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Yadav H, Torghabeh MH, Hoskote SS, Pennington KM, Lim KG, Scanlon PD, Niven AS, Hogan WJ. Adjusting diffusing capacity for anemia in patients undergoing allogeneic HCT: a comparison of two methodologies. Curr Res Transl Med 2024; 72:103432. [PMID: 38244276 PMCID: PMC11102530 DOI: 10.1016/j.retram.2023.103432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 10/16/2023] [Accepted: 11/17/2023] [Indexed: 01/22/2024]
Abstract
BACKGROUND Diffusing capacity (DLCO) measurements are affected by hemoglobin. Two adjustment equations are used: Cotes (recommended by ATS/ERS) and Dinakara (used in the hematopoietic stem cell transplantation comorbidity index [HCT-CI]). It is unknown how these methods compare, and which is better from a prognostication standpoint. STUDY DESIGN This is a retrospective cohort of 1273 adult patients who underwent allogeneic HCT, completed a pre-transplant DLCO and had a concurrent hemoglobin measurement. Non-relapse mortality was measured using competing risk analysis. RESULTS Patients had normal spirometry (FEV1 99.7% [IQR: 89.4-109.8%; FVC 100.1% [IQR: 91.0-109.6%] predicted), left ventricular ejection fraction (57.2[6.7]%) and right ventricular systolic pressure (30.1[7.0] mmHg). Cotes-DLCO was 85.6% (IQR: 76.5-95.7%) and Dinakara-DLCO was 103.6% (IQR: 90.7-117.2%) predicted. For anemic patients (Hb<10g/dL), Cotes-DLCO was 84.2% (IQR: 73.9-94.1%) while Dinakara-DLCO 111.0% (97.3-124.7%) predicted. Cotes-DLCO increased HCT-CI score for 323 (25.4%) and decreased for 4 (0.3%) patients. Cotes-DLCO was superior for predicting non-relapse mortality: for both mild (66-80% predicted, HR 1.55 [95%CI: 1.26-1.92, p < 0.001]) and moderate (<65% predicted, HR 2.11 [95%CI: 1.55-2.87, p<0.001]) impairment. In contrast, for Dinakara-DLCO, only mild impairment (HR 1.69 [95%CI 1.26-2.27, p < 0.001]) was associated with lower survival while moderate impairment was not (HR 1.44 [95%CI: 0.64-3.21, p = 0.4]). In multivariable analyses, after adjusting for demographics, hematologic variables, cardiac function and FEV1, Cotes-DLCO was predictive of overall survival at 1-year (OR 0.98 [95%CI: 0.97-1.00], p = 0.01), but Dinakara-DLCO was not (OR 1.00 [95%CI: 0.98-1.00], p = 0.20). CONCLUSION The ERS/ATS recommended Cotes method likely underestimates DLCO in patients with anemia, whereas the Dinakara (used in the HCT-CI score) overestimates DLCO. The Cotes method is superior to the Dinakara method score in predicting overall survival and relapse-free survival in patients undergoing allogeneic HCT.
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Affiliation(s)
- Hemang Yadav
- Division of Pulmonary and Critical Care Medicine, Pulmonary Function Laboratory, Mayo Clinic, Rochester, United States.
| | - Mehrdad Hefazi Torghabeh
- Division of Pulmonary and Critical Care Medicine, William J. von Liebig Center for Transplantation and Clinical Regeneration, Mayo Clinic, Rochester, United States
| | - Sumedh S Hoskote
- Division of Pulmonary and Critical Care Medicine, Pulmonary Function Laboratory, Mayo Clinic, Rochester, United States
| | - Kelly M Pennington
- Division of Hematology, William J. von Liebig Center for Transplantation and Clinical Regeneration, Mayo Clinic, Rochester, United States
| | - Kaiser G Lim
- Division of Pulmonary and Critical Care Medicine, Pulmonary Function Laboratory, Mayo Clinic, Rochester, United States
| | - Paul D Scanlon
- Division of Pulmonary and Critical Care Medicine, Pulmonary Function Laboratory, Mayo Clinic, Rochester, United States
| | - Alexander S Niven
- Division of Pulmonary and Critical Care Medicine, Pulmonary Function Laboratory, Mayo Clinic, Rochester, United States
| | - William J Hogan
- Division of Pulmonary and Critical Care Medicine, William J. von Liebig Center for Transplantation and Clinical Regeneration, Mayo Clinic, Rochester, United States
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Borland C, Patel R. Comparing in vitro nitric oxide blood uptake to its pulmonary diffusing capacity. Nitric Oxide 2024; 143:29-43. [PMID: 38135143 DOI: 10.1016/j.niox.2023.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 11/23/2023] [Accepted: 11/24/2023] [Indexed: 12/24/2023]
Abstract
Whether endothelium derived Nitric Oxide (NO) uptake by the blood is limited by a boundary layer, the red cell membrane or its interior is the subject of continued debate. Whether lung uptake of NO in the single-breath DLNO test is limited by blood or not is also debated. To understand which processes are limiting blood NO uptake we have modelled NO chemical kinetics and we have derived a shrinking core model, Thiele Modulus and FTCS (Euler) numerical solution. In a rapid reaction apparatus, NO uptake appears limited by a boundary layer, and throughout the red cell, by diffusion. In the single breath situation, and arguably with endogenous NO in vivo, NO uptake appears limited by a boundary layer and a pseudo first order chemical reaction in the outer molecular layers of the red cell. We have not found evidence to support red cell membrane limitation.
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Affiliation(s)
- Colin Borland
- Department of Medicine, University of Cambridge and Hinchingbrooke Hospital, Huntingdon, PE29 6NT, United Kingdom.
| | - Ruhi Patel
- Department of Chemical Engineering and Biotechnology, University of Cambridge, West Cambridge Site, Philippa Fawcett Drive, Cambridge, CB3 0AS, United Kingdom
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Magini A, Zavorsky GS, Apostolo A, Contini M, Barbieri S, Agostoni P. Week to week variability of pulmonary capillary blood volume and alveolar membrane diffusing capacity in patients with heart failure. Respir Physiol Neurobiol 2021; 290:103679. [PMID: 33962028 DOI: 10.1016/j.resp.2021.103679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/16/2021] [Accepted: 04/30/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Alveolar-capillary membrane diffusing capacity for carbon monoxide (DMCO) and pulmonary capillary volume (Vcap) can be estimated by the multi-step Roughton and Foster (RF, original method from 1957) or the single-step NO-CO double diffusion technique (developed in the 1980s). The latter method implies inherent assumptions. We sought to determine which combination of the alveolar membrane diffusing capacity for nitric oxide (DMNO) to DMCO ratio, an specific conductance of the blood for NO (θNO) and CO (θCO) gave the lowest week-to-week variability in patients with heart failure. METHODS 44 heart failure patients underwent DMCO and Vcap measurements on three occasions over a ten-week period using both RF and double dilution NO-CO techniques. RESULTS When using the double diffusing method and applying θNO = infinity, the smallest week-to-week coefficient of variation for DMCO was 10 %. Conversely, the RF method derived DMCO had a much greater week-to-week variability (2x higher coefficient of variation) than the DMCO derived via the NO-CO double dilution technique. The DMCO derived from the double diffusion technique most closely matched the DMCO from the RF method when θNO = infinity and DMCO = DLNO/2.42. The Vcap measured week-to-week was unreliable regardless of the method or constants used. CONCLUSIONS In heart failure patients, the week-to-week DMCO variability was lowest when using the single-step NO-CO technique. DMCO obtained from double diffusion most closely matched the RF DMCO when DMCO/2.42 and θNO = infinity. Vcap estimation was unreliable with either method.
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Affiliation(s)
| | - Gerald S Zavorsky
- Pulmonary Services Laboratory, UC Davis Medical Center, Sacramento, California, United States
| | | | | | | | - Piergiuseppe Agostoni
- Centro Cardiologico Monzino, IRCCS, Milano, Italy; Department of Clinical Sciences and Community Health, Cardiovascular Section, University of Milano, Milano, Italy.
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Abstract
This overview presents the recent progress in our understanding of gas transfer by the lungs during the respiratory cycle and during breath holding. Different phenomena intervene in gas transfer, convection and diffusion in the gas, dissolution, diffusion across the alveolar-capillary membrane, diffusion across blood plasma, and finally diffusion and reaction with hemoglobin inside blood cells. The different gases, O2 , CO, and NO, have very different reaction times with hemoglobin ranging from a few microseconds to tens of milliseconds. This is leading to different outcomes. For O2 , the solutions to the coupled nonlinear gas and blood equations are obtained at the acinus level. They include the fact that the acinar internal ventilation is strongly heterogeneous due to the arborescent structure. Also, in the dynamic calculation, one takes care of the delay between the start of inhalation and arrival of fresh air in the acinus. This "dead" time is the dynamic equivalent of the dead space ventilation. The question of the dependence of Vo2 on ventilation and perfusion takes a different form. The results show that Vo2 is not only a function of the ventilation/perfusion ratio but also depends on the variables: acinar ventilation VEac and perfusion Qac . The ratio VEac /Qac roughly determines arterial O2 saturation and arterial and alveolar O2 partial pressure. The classic Roughton-Forster interpretation of DLCO (separation between independent membrane and blood resistance) was a mathematical conjecture. It was shown recently that this conjecture was violated. This article presents an alternative interpretation that uses time concepts instead of resistance. © 2021 American Physiological Society. Compr Physiol 11:1289-1314, 2021.
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Affiliation(s)
- Bernard Sapoval
- Laboratoire de Physique de la Matière Condensée, CNRS, Ecole Polytechnique, Palaiseau, France
| | - Min-Yeong Kang
- Laboratoire de Physique de la Matière Condensée, CNRS, Ecole Polytechnique, Palaiseau, France
| | - Anh Tuan Dinh-Xuan
- Service de Physiologie-Explorations Fonctionnelles, Hôpital Cochin, AP-HP, Université Paris Descartes, Paris, France
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Yamaguchi K, Tsuji T, Aoshiba K, Nakamura H, Abe S. Can DL NO/DL CO ratio offset prejudicial effects of functional heterogeneities in acinar regions? Respir Physiol Neurobiol 2020; 282:103517. [PMID: 32805419 DOI: 10.1016/j.resp.2020.103517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 08/03/2020] [Indexed: 02/07/2023]
Abstract
OBJECTIVES (1) To establish the general equation that describes relationship of DMCO/Vc versus DLNO/DLCO under conditions with no functional heterogeneities. (2) To examine the effects of functional heterogeneities, including parallel and series (stratified) heterogeneities, on DLNO/DLCO. RESULTS AND DISCUSSIONS (1) Given that "true" θNO in pulmonary capillaries is represented by surface absorption-related θNO, relationship between DMCO/Vc and DLNO/DLCO does not differ significantly from that obtained on premise of infinite θNO. DLNO/DLCO decided physiologically may mirror morphometric DMCO/Vc actually working for gas exchange but not "total" morphometric ratio of DMCO/Vc. (2) There are three parallel heterogeneities that affect diffusing capacity (D)-related parameters. Of them, only the heterogeneity of D/VA, where VA is alveolar volume, underestimates DLCO and DLNO. DLNO/DLCO does not alleviate negative impact of D/VA heterogeneity, indicating that DMCO/Vc estimated from DLNO/DLCO does not mirror "true" morphometric DMCO/Vc in diseased lungs with D/VA maldistribution. (3) Stratified heterogeneity underrates morphometric DMCO, DMNO, and DMNO/DMCO maximally by 1.4 %, 2.8 %, and 1.4 %, respectively, under conditions similar to single-breath D measurements, suggesting that effect of stratified heterogeneity on D measures is no longer needed to be considered in normal subjects but may be in patients having lung diseases with destructive lesions of acinar structures.
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Affiliation(s)
- Kazuhiro Yamaguchi
- Department of Respiratory Medicine, Tokyo Medical University, Tokyo 160-0023, Japan.
| | - Takao Tsuji
- Department of Respiratory Medicine, Tokyo Medical University, Tokyo 160-0023, Japan
| | - Kazutetsu Aoshiba
- Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, Ibaraki 300-0395, Japan
| | - Hiroyuki Nakamura
- Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, Ibaraki 300-0395, Japan
| | - Shinji Abe
- Department of Respiratory Medicine, Tokyo Medical University, Tokyo 160-0023, Japan
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Yamaguchi K, Tsuji T, Aoshiba K, Nakamura H, Abe S. What are appropriate values of relative krogh diffusion Constant of NO against CO and of theta-NO in alveolar septa? Respir Physiol Neurobiol 2020; 276:103415. [PMID: 32068129 DOI: 10.1016/j.resp.2020.103415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 02/11/2020] [Accepted: 02/14/2020] [Indexed: 02/07/2023]
Abstract
OBJECTIVES To propose new physical constants for NO and CO (Krogh diffusion constant ratio (KDNO/CO) and specific blood conductance for NO (θNO)) for calculating DMCO and Vc, according to Roughton-Forster's equation (Roughton and Forster, J. Appl. Physiol. 11: 290-302, 1957) from simultaneous DLNO and DLCO measurements. RESULTS AND CONCLUSIONS (1) The Graham's law is unacceptable for determining KDNO/CO because CO does not fulfil all the conditions of an "ideal" gas. We have re-estimated KDNO/CO in a new way based on difference in molar volumes of two gases (molar volume theory). The KDNO/CO thus decided is 2.34. (2) θNO measured with rapid-reaction, constant-flow method by Carlsen and Comroe (J. Gen. Physiol. 42: 83-107, 1958) may be underestimated by about 40 % due to unstirred water layer surrounding the erythrocyte. (3) Erythrocyte θO2 can be harvested from O2 release kinetics in presence of high concentration of dithionite, which effectively removes the unstirred water layer-elicited effect. Multiplication of erythrocyte θO2 by erythrocyte KDNO/O2 equals erythrocyte θNO, the value of which is 6.2 mL/min/mmHg/(mL⋅blood). According to the concepts of Kang et al. (RESPNB. 241: 62-71, 2017) and Borland et al. (RESPNB. 241: 58-61, 2017), in vitro θNO decided from rapid-mixing experiments may mirror bulk absorption of NO by erythrocytes. (4) In pulmonary capillaries, NO uptake takes place predominantly in the surface rim of the erythrocyte. This surface absorption of NO increases the θNO 10-fold versus bulk absorption of NO to about 60 mL/min/mmHg/(mL⋅blood).
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Affiliation(s)
- Kazuhiro Yamaguchi
- Department of Respiratory Medicine, Tokyo Medical University, Tokyo 160-0023, Japan.
| | - Takao Tsuji
- Department of Respiratory Medicine, Tokyo Medical University, Tokyo 160-0023, Japan.
| | - Kazutetsu Aoshiba
- Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, Ibaraki 300-0395, Japan.
| | - Hiroyuki Nakamura
- Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, Ibaraki 300-0395, Japan.
| | - Shinji Abe
- Department of Respiratory Medicine, Tokyo Medical University, Tokyo 160-0023, Japan.
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D R Borland C, B Hughes JM. Lung Diffusing Capacities (D L ) for Nitric Oxide (NO) and Carbon Monoxide (CO): The Evolving Story. Compr Physiol 2019; 10:73-97. [PMID: 31853952 DOI: 10.1002/cphy.c190001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Nitric oxide and carbon monoxide diffusing capacities (DLNO and DLCO ) obey Fick's First Law of Diffusion and the basic principles of chemical kinetic theory. NO gas transfer is dominated by membrane diffusion (DM ), whereas CO transfer is limited by diffusion plus chemical reaction within the red cell. Marie Krogh, who pioneered the single-breath measurement of DLCO in 1915, believed that the combination of CO with red cell hemoglobin (Hb) was instantaneous. Roughton and colleagues subsequently showed, in vitro, that the reaction rate was finite, and prolonged in the presence of high P O 2 . Roughton and Forster (R-F) proposed that the resistance to transfer (1/DL ) was the sum of the membrane resistance (1/DM ) and (1/θVc), the red cell resistance (θ being the CO or NO conductance for blood uptake and Vc the capillary volume). From this R-F equation, DM for CO and Vc can be solved with simultaneous NO and CO inhalation. At near maximum exercise, DMCO and Vc for normal subjects were 88% and 79%, respectively, of morphometric values. The validity of these calculations depends on the values chosen for θ for CO and NO, and on the diffusivity of NO versus CO. Recent mathematical modeling suggests that θ for NO is "effectively" infinite because NO reacts only with Hb in the outer 0.1 μM of the red cell. An "infinite θNO " recalculation reduced DMCO to 53% and increased Vc to 95% of morphometric values. © 2020 American Physiological Society. Compr Physiol 10:73-97, 2020.
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Affiliation(s)
| | - J Mike B Hughes
- National Heart and Lung Institute, Imperial College, London, UK
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Desjardin A, Creveuil C, Bergot E, Normand H. Assessment of concordance between diffusion of carbon monoxide through the lung using the 10 s breath-hold method, and the simultaneous NO/CO technique, in healthy participants. Respir Physiol Neurobiol 2019; 273:103319. [PMID: 31654813 DOI: 10.1016/j.resp.2019.103319] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 09/23/2019] [Accepted: 10/08/2019] [Indexed: 11/18/2022]
Abstract
INTRODUCTION There is limited, large sample size, healthy control data comparing measurement of diffusing capacity of the lungs for carbon monoxide (DLCO) via the 10 s single-breath carbon monoxide uptake method (DLCO10) and using a DLCO-DLNO double diffusion test performed with a 5 s time of apnoea (DLCO5). OBJECTIVES The primary objective was to compare DLCO5 and DLCO10 in healthy participants. The secondary objective was to evaluate the reproducibility of DLCO5. MATERIAL AND METHODS We included medical students at Caen University Hospital, from 2008 to 2011. We performed a standard single-breath carbon monoxide uptake and combined DLCO and DLNO measurement for each participant. The combined test was repeated one week later. RESULTS Among the 153 study participants, there was no statistically significant difference between the mean values of DLCO10 (10.2 ± 2.2 mmol.min-1 kPa-1) and DLCO5 (10.3 ± 2.2 mmol.min-1 kPa-1; paired t-test p = 0.19). Corrected for the same FiO2, DLCO5 was calculated at 10.5 ± 2.3 mmol.min-1 kPa-1 and was significantly different from DLCO10 (paired t-test p < 0.001). DLCO5 deviates from 1,6 mmol.min-1 kPa-1 (4,6 mL.min-1. mmHg-1) or 15 % of DLCO10 (17 % above and 13% below, for 95 % of the subjects). Forty-seven participants were included in the DLCO5 reproducibility test. The 2 test sessions were carried out at 6 ± 2 day intervals. Reproducibilities for DLCO, DLNO, DmCO and Vc was respectively 1.2 (11 %), 6.8 (13%), 16.5 (32 %), 12.5 (17 %) mmol.min-1 kPa-1. CONCLUSION In healthy participants, discrepancies between DLCO measured during the double diffusion and DLCO measured on an apnoea of 10 s are quite large. It may be an indication that the Roughton and Forster interpretation to describe this type of measurements is inadequate.
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Affiliation(s)
- Amaury Desjardin
- Service de Pneumologie, Centre Hospitalier Universitaire, 14000 Caen, France
| | - Christian Creveuil
- Unité de Biostatistique et Recherche Clinique (UBRC), Centre Hospitalier Universitaire, 14000 Caen, France
| | - Emmanuel Bergot
- Service de Pneumologie, Centre Hospitalier Universitaire, 14000 Caen, France
| | - Hervé Normand
- Service des Explorations fonctionnelles, Centre Hospitalier Universitaire, 14000 Caen, France; Normandie University, Unicaen, Inserm Comete, GIP Cyceron, France.
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Borland C, Moggridge G, Patel R, Patel S, Zhu Q, Vuylsteke A. Permeability and diffusivity of nitric oxide in human plasma and red cells. Nitric Oxide 2018; 78:51-59. [PMID: 29787802 DOI: 10.1016/j.niox.2018.05.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 05/18/2018] [Accepted: 05/18/2018] [Indexed: 10/16/2022]
Abstract
A simple diffusion cell was made to measure the permeability and diffusivity of Nitric Oxide in human plasma and red cells. Nitric oxide was passed through the cell containing plasma or nitrited red cells enclosed by silicone membranes. Steady state permeability (αNODNO ) was calculated from the cell dimensions and from the NO bulk flow entering and leaving the cell. The diffusion coefficient (DNO) was calculated in three ways: (i) by dividing the steady state permeability by published values for solubility (αNO ) in water at 26 °C and 37 °C (ii) by a numerical method and (iii) by an analytical method. Mean steady state permeability (95% confidence intervals) were plasma (26 °C) 5.57 × 10-11 (2.35 × 10-11-1.32 × 10-10) and (37 °C) 5.48 × 10-11 (2.13 × 10-11-1.41 × 10-10) mol cm-1 s-1 atm-1 and red cells (26 °C) 6.74 × 10-12 (1.29 × 10-12-3.53 × 10-11) and (37 °C) 3.93 × 10-11 (1.39 × 10-11-1.11.10-10) mol cm-1 s-1 atm-1. Median Diffusion Coefficients (DNO) for plasma at 37 °C ranged from 3-3.36 × 10-5 cm2 s-1 and red cells 2.41-2.94 × 10-5 cm2 s-1 depending on the method used. These values may be used for modelling NO transport in vivo in the human lung and capillary. Parameters used for modelling in vivo should be measured at 37 °C.
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Affiliation(s)
- Colin Borland
- Department of Medicine, University of Cambridge and Hinchingbrooke Hospital, Huntingdon PE29 6NT, United Kingdom.
| | - Geoff Moggridge
- Department of Chemical Engineering and Biotechnology, University of Cambridge, West Cambridge Site, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom.
| | - Ruhi Patel
- Department of Chemical Engineering and Biotechnology, University of Cambridge, West Cambridge Site, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom.
| | - Suhani Patel
- Department of Respiratory Physiology, Papworth Hospital, Papworth Everard, Cambridgeshire CB23 3RE, United Kingdom.
| | - Qingyu Zhu
- Department of Chemical Engineering and Biotechnology, University of Cambridge, West Cambridge Site, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom.
| | - Alain Vuylsteke
- Department of Anaesthesia and Intensive Care, Papworth Hospital, Papworth Everard, Cambridgeshire CB23 3RE, United Kingdom.
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Degano B, Soumagne T, Delaye T, Berger P, Perez T, Guillien A, Pellegrin JL, Launay D, Magy-Bertrand N, Agard C, Tiev KP, Hua-Huy T, Tardiff C, Diaz V, Chambellan A, Dinh-Xuan AT. Combined measurement of carbon monoxide and nitric oxide lung transfer does not improve the identification of pulmonary hypertension in systemic sclerosis. Eur Respir J 2017; 50:50/4/1701008. [DOI: 10.1183/13993003.01008-2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 07/20/2017] [Indexed: 12/11/2022]
Abstract
Screening is important to determine whether patients with systemic sclerosis (SSc) have pulmonary hypertension because earlier pulmonary hypertension treatment can improve survival in these patients. Although decreased transfer factor of the lung for carbon monoxide (TLCO) is currently considered the best pulmonary function test for screening for pulmonary hypertension in SSc, small series have suggested that partitioning TLCO into membrane conductance (diffusing capacity) for carbon monoxide (DMCO) and alveolar capillary blood volume (VC) through combined measurement of TLCO and transfer factor of the lung for nitric oxide (TLNO) is more effective to identify pulmonary hypertension in SSc patients compared with TLCO alone. Here, the objective was to determine whether combined TLCO–TLNO partitioned with recently refined equations could more accurately detect pulmonary hypertension than TLCO alone in SSc.For that purpose, 572 unselected consecutive SSc patients were retrospectively recruited in seven French centres.Pulmonary hypertension was diagnosed with right heart catheterisation in 58 patients. TLCO, TLNO and VC were all lower in SSc patients with pulmonary hypertension than in SSc patients without pulmonary hypertension. The area under the receiver operating characteristic curve for the presence of pulmonary hypertension was equivalent for TLCO (0.82, 95% CI 0.79–0.85) and TLNO (0.80, 95% CI 0.76–0.83), but lower for VC (0.75, 95% CI 0.71–0.78) and DMCO (0.66, 95% CI 0.62–0.70).Compared with TLCO alone, combined TLCO–TLNO does not add capability to detect pulmonary hypertension in unselected SSc patients.
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Kang MY, Guénard H, Sapoval B. Diffusion Reaction of Carbon Monoxide in the Human Lung. PHYSICAL REVIEW LETTERS 2017; 119:078101. [PMID: 28949676 DOI: 10.1103/physrevlett.119.078101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Indexed: 06/07/2023]
Abstract
The capture of CO, a standard lung function test, results from diffusion-reaction processes of CO with hemoglobin inside red blood cells (RBCs). In its current understanding, suggested by Roughton and Forster in 1957, the capture is represented by two independent resistances in series, one for diffusion from the gas to the RBC periphery, the second for internal diffusion reaction. Numerical studies in 3D model structures described here contradict the independence hypothesis. This results from two different theoretical reasons: (i) The RBC peripheries are not equi-concentrations; (ii) diffusion times in series are not additive.
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Affiliation(s)
- M-Y Kang
- Laboratoire de Physique de la Matière Condensée, Ecole Polytechnique, CNRS, Université Paris-Saclay, 91128 Palaiseau Cedex, France
| | - H Guénard
- Laboratoire de Physiologie, Université Bordeaux 2, 33076 Bordeaux, France
| | - B Sapoval
- Laboratoire de Physique de la Matière Condensée, Ecole Polytechnique, CNRS, Université Paris-Saclay, 91128 Palaiseau Cedex, France
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Zavorsky GS. Nitric oxide uptake in the lung: It is about time that clinicians use this test routinely. Respir Physiol Neurobiol 2017; 241:1-2. [PMID: 28323204 DOI: 10.1016/j.resp.2017.03.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Gerald S Zavorsky
- Department of Respiratory Therapy, Georgia State University, Georgia State University Urban Life Building, Room 1229 (12th Floor), 140 Decatur Street SE, Atlanta, GA, 30302-4019, United States.
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