scholarly journals Physiological signature of late-onset nonallergic asthma of obesity

2020 ◽  
Vol 6 (3) ◽  
pp. 00049-2020
Author(s):  
Anne E. Dixon ◽  
Ubong Peters ◽  
Ryan Walsh ◽  
Nirav Daphtary ◽  
Erick S. MacLean ◽  
...  
Keyword(s):  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Late Onset ◽  
Nitrogen Washout ◽  
Dead Space Volume ◽  
Residual Capacity ◽  
Obese Subjects ◽  
Obese Control ◽  
Asthma Group ◽  
Space Volume

IntroductionObesity can lead to a late-onset nonallergic (LONA) form of asthma for reasons that are not understood. We sought to determine whether this form of asthma is characterised by any unique physiological features.MethodsSpirometry, body plethysmography, multiple breath nitrogen washout (MBNW) and methacholine challenge were performed in four subject groups: Lean Control (n=11), Lean Asthma (n=11), Obese Control (n=11) and LONA Obese Asthma (n=10). The MBNW data were fitted with a novel computational model that estimates functional residual capacity (FRC), dead space volume (VD), the coefficient of variation of regional specific ventilation (CV,V′E) and a measure of structural asymmetry at the level of the acinus (sacin).ResultsBody mass index and waist circumference values were similar in both obese groups, and significantly greater than in lean asthmatic individuals and controls. Forced vital capacity was significantly lower in the LONA Asthma group compared with the other groups (p<0.001). Both asthma groups exhibited similar hyperresponsiveness to methacholine. FRC was reduced in the Obese LONA Asthma group as measured by MBNW, but not in obese controls, whereas FRC was reduced in both obese groups as measured by plethysmography. VD, CV,V′E and sacin were not different between groups.ConclusionsChronic lung compression characterises all obese subjects, as reflected by reduced plethysmographic FRC. Obese LONA asthma is characterised by a reduced ability to recruit closed lung units, as seen by reduced MBNW FRC, and an increased tendency for airway closure as seen by a reduced forced vital capacity.

scholarly journals A model-based approach to interpreting multibreath nitrogen washout data

2018 ◽  
Vol 124 (5) ◽  
pp. 1155-1163 ◽  
Author(s):  
Jason H. T. Bates ◽  
Ubong Peters
Keyword(s):  
Functional Residual Capacity ◽  
Dead Space ◽  
Test Subject ◽  
Phase Iii ◽  
Nitrogen Washout ◽  
Model Based ◽  
Dead Space Volume ◽  
Residual Capacity ◽  
The Subject ◽  
Space Volume

The multibreath nitrogen washout (MBNW) test, as it is currently practiced, provides parameters of potential physiological significance that are derived from the relationship between the volume-normalized Phase III slope of the exhaled nitrogen fraction ([Formula: see text]) vs. the cumulative change in lung volume (V). Reliable evaluation of these parameters requires, however, that the subject breathe deeply and evenly, so that Phase III can be clearly identified in every breath. This places a burden on the test subject that may prove troublesome for young children and those with lung disease. Furthermore, the determination of the slope of Phase III requires that a decision be made as to when Phase II ends and Phase III begins. In an attempt to get around these methodological limitations, we develop here an alternative method of analysis based on a multicompartment model of the lung that accounts for the entire exhaled nitrogen profile, including Phases I, II, and III. Fitting this model to [Formula: see text] and V measured during a MBNW provides an estimate of the coefficient of variation of specific ventilation, as well as functional residual capacity, dead space volume, and a parameter that reflects structural asymmetry at the acinar level in the lung. In the present study, we demonstrate the potential utility of this modeling approach to the analysis of MBNW data. NEW & NOTEWORTHY The multibreath nitrogen washout test potentially provides important physiological information about regional ventilation heterogeneity throughout the lung, but the conventional analysis requires the subject to breathe deeply and regularly, which is not always practical. We have developed a model-based analysis method that avoids this limitation and that also provides measures of functional residual capacity and dead space volume, thereby expanding the applicability and scope of the method.

Deep breaths, methacholine, and airway narrowing in healthy and mild asthmatic subjects

2002 ◽  
Vol 93 (4) ◽  
pp. 1384-1390 ◽  
Author(s):  
Emanuele Crimi ◽  
Riccardo Pellegrino ◽  
Manlio Milanese ◽  
Vito Brusasco
Keyword(s):  
Forced Vital Capacity ◽  
Healthy Subjects ◽  
Vital Capacity ◽  
Forced Expiratory Volume ◽  
Forced Expiration ◽  
Airway Narrowing ◽  
Significant Difference ◽  
Mild Asthmatic ◽  
Residual Capacity ◽  
Airway Conductance

Deep breaths taken before inhalation of methacholine attenuate the decrease in forced expiratory volume in 1 s and forced vital capacity in healthy but not in asthmatic subjects. We investigated whether this difference also exists by using measurements not preceded by full inflation, i.e., airway conductance, functional residual capacity, as well as flow and residual volume from partial forced expiration. We found that five deep breaths preceding a single dose of methacholine 1) transiently attenuated the decrements in forced expiratory volume in 1 s and forced vital capacity in healthy ( n = 8) but not in mild asthmatic ( n = 10) subjects and 2) increased the areas under the curve of changes in parameters not preceded by a full inflation over 40 min, during which further deep breaths were prohibited, without significant difference between healthy ( n = 6) and mild asthmatic ( n = 16) subjects. In conclusion, a series of deep breaths preceding methacholine inhalation significantly enhances bronchoconstrictor response similarly in mild asthmatic and healthy subjects but facilitates bronchodilatation on further full inflation in the latter.

scholarly journals Small airway function in obese individuals with self-reported asthma

2020 ◽  
Vol 6 (2) ◽  
pp. 00371-2019
Author(s):  
Beno W. Oppenheimer ◽  
Roberta M. Goldring ◽  
Israa Soghier ◽  
David Smith ◽  
Manish Parikh ◽  
...  
Keyword(s):  
Clinical History ◽  
Small Airway ◽  
Obese People ◽  
Airway Function ◽  
Residual Capacity ◽  
Obese Subjects ◽  
Healthy Obese ◽  
Similar Body ◽  
Metabolic Comorbidities ◽  
Asthma Group

Diagnosis of asthma in obese individuals frequently relies on clinical history, as airflow by spirometry may remain normal. This study hypothesised that obese subjects with self-reported asthma and normal spirometry will demonstrate distinct clinical characteristics, metabolic comorbidities and enhanced small airway dysfunction as compared with healthy obese subjects.Spirometry, plethysmography and oscillometry data pre/post-bronchodilator were obtained in 357 obese subjects in three groups as follows: no asthma group (n=180), self-reported asthma normal spirometry group (n=126), and asthma obstructed spirometry group (n=51). To assess the effects of obesity related to reduced lung volume, oscillometry measurements were repeated during a voluntary inflation to predicted functional residual capacity (FRC).Dyspnoea was equally prevalent in all groups. In contrast, cough, wheeze and metabolic comorbidities were more frequent in the asthma normal spirometry and asthma obstructed spirometry groups versus the no asthma group (p<0.05). Despite similar body size, oscillometry measurements demonstrated elevated R5–20 (difference between resistance at 5 and 20 Hz) in the no asthma and asthma normal spirometry groups (0.19±0.12; 0.23±0.13 kPa/(L·s−1), p<0.05) but to a lesser degree than the asthma obstructed spirometry group (0.34±0.20 kPa/(L·s−1), p<0.05). Differences between groups persisted post-bronchodilator (p<0.05). Following voluntary inflation to predicted FRC, R5–20 in the no asthma and asthma normal spirometry groups fell to similar values, indicating a reversible process (0.11±0.07; 0.12±0.08 kPa/(L·s−1), p=NS). Persistently elevated R5–20 was seen in the asthma obstructed spirometry group, suggesting chronic inflammation and/or remodelling (0.17±0.11 kPa/(L·s−1), p<0.05).Thus, small airway abnormalities of greater magnitude than observations in healthy obese people may be an early marker of asthma in obese subjects with self-reported disease despite normal airflow. Increased metabolic comorbidities in these subjects may have provided a milieu that impacted airway function.

Mode shift of an inhaled aerosol bolus is correlated with flow sequencing in the human lung

2002 ◽  
Vol 92 (3) ◽  
pp. 1232-1238 ◽  
Author(s):  
Christopher N. Mills ◽  
Chantal Darquenne ◽  
G. Kim Prisk
Keyword(s):  
Vital Capacity ◽  
Normal Subjects ◽  
Phase Iii ◽  
Mode Shift ◽  
Nitrogen Washout ◽  
Single Breath ◽  
Posture Change ◽  
Supine Posture ◽  
Residual Capacity ◽  
Phase Iii Slope

We studied the effects on aerosol bolus inhalations of small changes in convective inhomogeneity induced by posture change from upright to supine in nine normal subjects. Vital capacity single-breath nitrogen washout tests were used to determine ventilatory inhomogeneity change between postures. Relative to upright, supine phase III slope was increased 33 ± 11% (mean ± SE, P < 0.05) and phase IV height increased 25 ± 11% ( P < 0.05), consistent with an increase in convective inhomogeneity likely due to increases in flow sequencing. Subjects also performed 0.5-μm-particle bolus inhalations to penetration volumes (Vp) between 150 and 1,200 ml during a standardized inhalation from residual volume to 1 liter above upright functional residual capacity. Mode shift (MS) in supine posture was more mouthward than upright at all Vp, changing by 11.6 ml at Vp = 150 ml ( P < 0.05) and 38.4 ml at Vp = 1,200 ml ( P < 0.05). MS and phase III slope changes correlated positively at deeper Vp. Deposition did not change at any Vp, suggesting that deposition did not cause the MS change. We propose that the MS change results from increased sequencing in supine vs. upright posture.

scholarly journals Forced vital capacity and cross-domain late-onset Pompe disease outcomes: an individual patient-level data meta-analysis

2019 ◽  
Vol 266 (9) ◽  
pp. 2312-2321
Author(s):  
Kenneth I. Berger ◽  
Steve Kanters ◽  
Jeroen P. Jansen ◽  
Andrew Stewart ◽  
Susan Sparks ◽  
...  
Keyword(s):  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Late Onset ◽  
Meta Analysis ◽  
Patient Level Data ◽  
Individual Patient Level ◽  
Patient Level ◽  
Cross Domain ◽  
Disease Outcomes ◽  
Level Data

Detection of Ventilation Unevenness by Nitrogen Washout and Forced Vital Capacity Manoeuvres: Its Limits and Reliability

Respiration ◽  
1985 ◽  
Vol 48 (2) ◽  
pp. 145-152
Author(s):  
Raffaele Antonelli Incalzi ◽  
Riccardo Pistelli ◽  
Vincenzo Locci ◽  
Francesco Patalano ◽  
Sergio Maria Liberatore ◽  
...  
Keyword(s):  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Nitrogen Washout

Gravity effects on regional lung ventilation determined by functional EIT during parabolic flights

2001 ◽  
Vol 91 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Inéz Frerichs ◽  
Taras Dudykevych ◽  
José Hinz ◽  
Marc Bodenstein ◽  
Günter Hahn ◽  
...  
Keyword(s):  
Lung Volume ◽  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Lung Ventilation ◽  
Tidal Breathing ◽  
Parabolic Flights ◽  
Regional Lung ◽  
Residual Capacity ◽  
The Right ◽  
Regional Lung Ventilation

Gravity-dependent changes of regional lung function were studied during normogravity, hypergravity, and microgravity induced by parabolic flights. Seven healthy subjects were followed in the right lateral and supine postures during tidal breathing, forced vital capacity, and slow expiratory vital capacity maneuvers. Regional 1) lung ventilation, 2) lung volumes, and 3) lung emptying behavior were studied in a transverse thoracic plane by functional electrical impedance tomography (EIT). The results showed gravity-dependent changes of regional lung ventilation parameters. A significant effect of gravity on regional functional residual capacity with a rapid lung volume redistribution during the gravity transition phases was established. The most homogeneous functional residual capacity distribution was found at microgravity. During vital capacity and forced vital capacity in the right lateral posture, the decrease in lung volume on expiration was larger in the right lung region at all gravity phases. During tidal breathing, the differences in ventilation magnitudes between the right and left lung regions were not significant in either posture or gravity phase. A significant nonlinearity of lung emptying was determined at normogravity and hypergravity. The pattern of lung emptying was homogeneous during microgravity.

Modeling of changes in forced vital capacity and late-onset Pompe disease related outcomes

2017 ◽  
Vol 120 (1-2) ◽  
pp. S62
Author(s):  
Alaa Hamed ◽  
Steve Kanters ◽  
Andrew Stewart ◽  
Milki Tilimo ◽  
Anna Bolzani ◽  
...  
Keyword(s):  
Forced Vital Capacity ◽  
Pompe Disease ◽  
Vital Capacity ◽  
Late Onset

scholarly journals Effects of rapid saline infusion on lung mechanics and airway responsiveness in humans

2003 ◽  
Vol 95 (2) ◽  
pp. 728-734 ◽  
Author(s):  
Riccardo Pellegrino ◽  
Raffaele Dellacà ◽  
Peter T. Macklem ◽  
Andrea Aliverti ◽  
Stefania Bertini ◽  
...  
Keyword(s):  
Functional Residual Capacity ◽  
Forced Vital Capacity ◽  
Vital Capacity ◽  
Forced Expiratory Volume ◽  
Airway Responsiveness ◽  
Saline Infusion ◽  
Lung Mechanics ◽  
Elastic Recoil ◽  
Lung Volumes ◽  
Residual Capacity

Lung mechanics and airway responsiveness to methacholine (MCh) were studied in seven volunteers before and after a 20-min intravenous infusion of saline. Data were compared with those of a time point-matched control study. The following parameters were measured: 1-s forced expiratory volume, forced vital capacity, flows at 40% of control forced vital capacity on maximal (V̇m40) and partial (V̇p40) forced expiratory maneuvers, lung volumes, lung elastic recoil, lung resistance (Rl), dynamic elastance (Edyn), and within-breath resistance of respiratory system (Rrs). Rl and Edyn were measured during tidal breathing before and for 2 min after a deep inhalation and also at different lung volumes above and below functional residual capacity. Rrs was measured at functional residual capacity and at total lung capacity. Before MCh, saline infusion caused significant decrements of forced expiratory volume in 1 s, V̇m40, and V̇p40, but insignificantly affected lung volumes, elastic recoil, Rl, Edyn, and Rrs at any lung volume. Furthermore, saline infusion was associated with an increased response to MCh, which was not associated with significant changes in the ratio of V̇m40 to V̇p40. In conclusion, mild airflow obstruction and enhanced airway responsiveness were observed after saline, but this was not apparently due to altered elastic properties of the lung or inability of the airways to dilate with deep inhalation. It is speculated that it was likely the result of airway wall edema encroaching on the bronchial lumen.

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