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Gerald S Zavorsky, Ivo van der Lee
Pulmonary diffusing capacity for carbon monoxide (DLCO) has been an important pulmonary function test used since the 1950's. It measures the uptake of CO from the alveolar space into pulmonary capillary blood, following the same path as oxygen. It's used to evaluate/follow the progress of various lung diseases. In the eighties, a new test was developed similar to the DLCO test: pulmonary diffusing capacity for nitric oxide (DLNO). About 81-90% of the variance in DLNO is shared by DLCO in patients with cardiopulmonary disease and in healthy subjects...
November 21, 2016: Respiratory Physiology & Neurobiology
Natalie E Taylor, Sarah E Baker, Thomas P Olson, Sophie Lalande, Bruce D Johnson, Eric M Snyder
BACKGROUND: Beta-2 adrenergic receptors (β2ARs) are located throughout the body including airway and alveolar cells. The β2ARs regulate lung fluid clearance through a variety of mechanisms including ion transport on alveolar cells and relaxation of the pulmonary lymphatics. We examined the effect of an inhaled β2-agonist (albuterol) on alveolar-capillary membrane conductance (DM) and pulmonary capillary blood volume (VC) in healthy humans. METHODS: We assessed the diffusing capacity of the lungs for carbon monoxide (DLCO) and nitric oxide (DLNO) at baseline, 30 minutes, and 60 minutes following nebulized albuterol (2...
2016: Clinical Medicine Insights. Circulatory, Respiratory and Pulmonary Medicine
Laurent Godinas, David Amar, David Montani, Edmund M Lau, Xavier Jaïs, Laurent Savale, Mitja Jevnikar, Olivier Sitbon, Gérald Simonneau, Marc Humbert, Pierantonio Laveneziana, Gilles Garcia
BACKGROUND: Combined diffusion capacity of the lung for carbon monoxide (DLco) and nitric oxide (DLno) measurements allow for the estimation of pulmonary capillary blood volume (Vc) and alveolar membrane diffusion (Dm). The clinical usefulness of these measurements in pulmonary hypertension (PH) is unclear. METHODS: Combined DLco and DLno were measured in 290 consecutive patients with precapillary PH (pulmonary arterial hypertension (PAH), n = 153; pulmonary veno-occlusive disease (PVOD), n = 33; and chronic thromboembolic pulmonary hypertension (CTEPH), n = 104)...
May 2016: Journal of Heart and Lung Transplantation
Giovanni Barisione, Claudia Brusasco, Alessandro Garlaschi, Michele Baroffio, Vito Brusasco
Lung diffusing capacity for carbon monoxide (DLCO) is decreased in both usual interstitial pneumonia-idiopathic pulmonary fibrosis (UIP-IPF) and nonspecific interstitial pneumonia (NSIP), but is moderately related to computed tomography (CT)-determined fibrotic changes. This may be due to the relative insensitivity of DLCO to changes in alveolar membrane diffusive conductance (DMCO). The purpose of this study was to determine whether measurement of lung diffusing capacity for nitric oxide (DLNO) better reflects fibrotic changes than DLCO DLNO-DLCO were measured simultaneously in 30 patients with UIP-IPF and 30 with NSIP...
May 1, 2016: Journal of Applied Physiology
Min-Yeong Kang, Bernard Sapoval
Capture of CO and NO by blood requires molecules to travel by diffusion from alveolar gas to haemoglobin molecules inside RBCs and then to react. One can attach to these processes two times, a time for diffusion and a time for reaction. This reaction time is known from chemical kinetics and, therefore, constitutes a unique physical clock. This paper presents a time-based bottom-up theory that yields a simple expression for DLCO and DLNO that produces quantitative predictions which compare successfully with experiments...
May 2016: Respiratory Physiology & Neurobiology
Bryan J Taylor, Kirsten E Coffman, Douglas T Summerfield, Amine N Issa, Alex J Kasak, Bruce D Johnson
PURPOSE: We determined whether well-acclimatized humans have a reserve to recruit pulmonary capillaries in response to exercise at high altitude. METHODS: At sea level, lung diffusing capacity for carbon monoxide (DLCO), alveolar-capillary membrane conductance (DmCO), and pulmonary capillary blood volume (V c) were measured at rest before maximal oxygen consumption ([Formula: see text]) was determined in seven adults. Then, DLCO, DmCO and V c were measured pre- and post-exhaustive incremental exercise at 5150 m after ~40 days of acclimatization...
February 2016: European Journal of Applied Physiology
A Le Bourgeois, F Malard, P Chevallier, G Urbistandoy, T Guillaume, J Delaunay, P Peterlin, P Lemarchand, P Germaud, M Mohty, P Moreau, A Chambellan
No abstract text is available yet for this article.
April 2016: Bone Marrow Transplantation
Jean Benoit Martinot, Hervé Guénard, Anh-Tuan Dinh-Xuan, Henri Gin, Claire Dromer
Just a few clinicians routinely measure the subcomponents of the lung diffusing capacity for Carbone monoxide (DLCO ). This is because the measurement of membrane and blood conductances for CO (DmCO and DbCO  = θCO  × Vc , respectively) by the classic Roughton and Forster method is complicated and time consuming. In addition, it mistakenly assumes a close relationship between alveolar oxygen partial pressure (PAO2 ) and mean intracapillary oxygen partial pressure (PcapO2 ) which is the true determinant of specific conductance of haemoglobin for CO (θCO )...
November 17, 2015: Clinical Physiology and Functional Imaging
Kirsten E Coffman, Bryan J Taylor, Alex R Carlson, Robert J Wentz, Bruce D Johnson
Alveolar-capillary membrane conductance (D(M,CO)) and pulmonary-capillary blood volume (V(C)) are calculated via lung diffusing capacity for carbon monoxide (DL(CO)) and nitric oxide (DL(NO)) using the single breath, single oxygen tension (single-FiO2) method. However, two calculation parameters, the reaction rate of carbon monoxide with blood (θ(CO)) and the D(M,NO)/D(M,CO) ratio (α-ratio), are controversial. This study systematically determined optimal θ(CO) and α-ratio values to be used in the single-FiO2 method that yielded the most similar D(M,CO) and V(C) values compared to the 'gold-standard' multiple-FiO2 method...
January 15, 2016: Respiratory Physiology & Neurobiology
Courtney M Wheatley, Sarah E Baker, Mary A Morgan, Marina G Martinez, Wayne J Morgan, Eric C Wong, Stephen R Karpen, Eric M Snyder
BACKGROUND: Although exercise is a vital component of the therapy prescribed to individuals with cystic fibrosis (CF), it is not a priority due to a finite amount of treatment time and the view that exercise is not as beneficial as pharmacological treatments by many individuals with CF. We sought to compare the therapeutic benefits of exercise and their prescribed bronchodilator albuterol. METHODS: CF (n = 14) and healthy (n = 16) subjects completed three visits, a baseline screening with VO2 max test and two treatment visits...
April 2015: Respiratory Medicine
U Schulz, S Langwieler, S Riedel, J Schreiber
Reduced pulmonary diffusion capacity is a hallmark of COPD, although the relative contribution of the subcomponents of pulmonary diffusion--membranous component (Dm) and capillary volume (Vc)--is unknown. These components can be measured with the method of NO single-breath diffusion (DLNO). In a prospective study, pulmonary function tests including spirometry, body plethysmography and single-breath measurements of diffusion capacity with CO and NO were performed in 183 patients with COPD of varying severity...
April 2014: Pneumologie
Giovanni Barisione, Andrea Bacigalupo, Claudia Brusasco, Chiara Scanarotti, Susanna Penco, Anna Maria Bassi, Teresa Lamparelli, Alessandro Garlaschi, Riccardo Pellegrino, Vito Brusasco
Lung diffusing capacity for CO (DLCO) is compromised in haematopoietic stem-cell transplantation (HSCT) recipients. We derived alveolar-capillary membrane conductance (DM,CO) and pulmonary capillary volume (VC) from DLCO and diffusing capacity for NO (DLNO). Forty patients were studied before and 6 weeks after HSCT. Before HSCT, DLNO and DLCO were significantly lower than in 30 healthy controls. DM,CO was ∼40% lower in patients than in controls (p<0.001), whereas VC did not differ significantly. After HSCT, DLNO and DM,CO further decreased, the latter by ∼22% from before HSCT (p<0...
April 1, 2014: Respiratory Physiology & Neurobiology
Andrew R Martin, Chris Jackson, Ira M Katz, Georges Caillibotte
BACKGROUND: Nitric oxide (NO) is currently administered using devices that maintain constant inspired NO concentrations. Alternatively, devices that deliver a pulse of NO during the early phase of inspiration may have use in optimizing NO dosing efficiency and in extending application of NO to long-term use by ambulatory, spontaneously breathing patients. The extent to which the amount of NO delivered for a given pulse sequence determines alveolar concentrations and uptake, and the extent to which this relationship varies with breathing pattern, physiological, and pathophysiological parameters, warrants investigation...
2014: Medical Gas Research
Joseph M Flaherty, James M Smoliga, Gerald S Zavorsky
The purpose of the study was to determine whether short-term high-intensity aerobic interval training improves resting pulmonary diffusing capacity for nitric oxide (DLNO) and carbon monoxide (DLCO). Twenty-eight sedentary women [mean (SD) age 32 (11) years, body mass index 24.3 (5.7) kg m(-2)] were randomly assigned to either a self-directed moderate-intensity physical activity (n = 14) group or a supervised high-intensity aerobic interval training group (n = 14). The moderate physical activity group and the aerobic interval training group increased weekly physical activity energy expenditure by 800 and 1600 kcal week(-1), respectively...
March 2014: Experimental Physiology
Colin Borland, Fiona Bottrill, Aled Jones, Chris Sparkes, Alain Vuylsteke
The lung nitric oxide (NO) diffusing capacity (DlNO) mainly reflects alveolar-capillary membrane conductance (Dm). However, blood resistance has been shown in vitro and in vivo. To explore whether this resistance lies in the plasma, the red blood cell (RBC) membrane, or in the RBC interior, we measured the NO diffusing capacity (Dno) in a membrane oxygenator circuit containing ∼1 liter of horse or human blood exposed to 14 parts per million NO under physiological conditions on 7 separate days. We compared results across a 1,000-fold change in extracellular diffusivity using dextrans, plasma, and physiological salt solution...
January 1, 2014: Journal of Applied Physiology
Nadia Sivova, David Launay, Lidwine Wémeau-Stervinou, Pascal De Groote, Martine Remy-Jardin, Guillaume Denis, Marc Lambert, Nicolas Lamblin, Sandrine Morell-Dubois, Marie Fertin, Guillaume Lefevre, Vincent Sobanski, Olivier Le Rouzic, Pierre-Yves Hatron, Benoit Wallaert, Eric Hachulla, Thierry Perez
We investigated whether partitioning DLCO into membrane conductance for CO (DmCO) and pulmonary capillary blood volume (Vcap) was helpful in suspecting precapillary pulmonary (arterial) hypertension (P(A)H) in systemic sclerosis (SSc) patients with or without interstitial lung disease (ILD). We included 63 SSc patients with isolated PAH (n=6), isolated ILD (n=19), association of both (n=12) or without PAH and ILD (n=26). Partitioning of DLCO was performed by the combined DLNO/DLCO method. DLCO, DmCO and Vcap were equally reduced in patients with isolated PAH and patients with isolated ILD but Vcap/alveolar volume (VA) ratio was significantly lower in the isolated PAH group...
2013: PloS One
Alessandra Magini, Anna Apostolo, Elisabetta Salvioni, Gianpiero Italiano, Fabrizio Veglia, Piergiuseppe Agostoni
BACKGROUND: In heart failure, lung diffusion is reduced, it correlates with prognosis and exercise capacity, and it is a therapy target. DESIGN: Diffusion is measured as CO total diffusion (DL(CO)), which has two components: membrane diffusion (Dm) and capillary volume, the latter related to CO and O2 competition for hemoglobin. DL(CO) needs to be corrected for hemoglobin. Diffusion can also be measured with NO (DL(NO)), which has a very high affinity for hemoglobin, and thus, the resistance of hemoglobin being trivial, it directly represents Dm...
February 2015: European Journal of Preventive Cardiology
Dag Linnarsson, Tryggve E Hemmingsson, Claes Frostell, Alain Van Muylem, Yannick Kerckx, Lars E Gustafsson
Lung diffusing capacity for NO (DLNO) was determined in eight subjects at ambient pressures of 505, 1015, and 4053hPa (379, 761 and 3040mmHg) as they breathed normoxic gases. Mean values were 116.9±11.1 (SEM), 113.4±11.1 and 99.3±10.1mlmin(-1)hPa(-1)at 505, 1015, and 4053hPa, with a 13% difference between the two higher pressures (P=0.017). The data were applied to a model with two serially coupled conductances; the gas phase (DgNO, variable with pressure), and the alveolo-capillary membrane (DmNO, constant)...
December 1, 2013: Respiratory Physiology & Neurobiology
Gerald S Zavorsky
The purpose of this study determined the rise in carboxyhemoglobin percentage (COHb) from repeated pulmonary diffusing capacity tests using 5 or 10s single breath-hold maneuvers. Five male and four female non-smokers [baseline COHb=1.2 (SD 0.5%)] performed repeated pulmonary diffusing capacity testing on two separate days. The days were randomized to either repeated 10s (0.28% CO), or 5s (0.28% CO, 55ppm NO) breath-hold maneuvers. Twenty-two 5s breath-hold maneuvers, each separated by 4min rest, raised COHb to 11...
March 1, 2013: Respiratory Physiology & Neurobiology
Kaleen M Lavin, Allison M Straub, Kathleen A Uhranowsky, James M Smoliga, Gerald S Zavorsky
PURPOSE: (1) to examine the relation between pulmonary diffusing capacity and marathon finishing time, and (2), to evaluate the accuracy of pulmonary diffusing capacity for nitric oxide (DLNO) in predicting marathon finishing time relative to that of pulmonary diffusing capacity for carbon monoxide (DLCO). METHODS: 28 runners [18 males, age = 37 (SD 9) years, body mass = 70 (13) kg, height = 173 (9) cm, percent body fat = 17 (7) %] completed a test battery consisting of measurement of DLNO and DLCO at rest, and a graded exercise test to determine running economy and aerobic capacity prior to the 2011 Steamtown Marathon (Scranton, PA)...
2012: PloS One
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