scholarly journals Ventilation distribution during histamine provocation

1997 ◽  
Vol 83 (6) ◽  
pp. 1907-1916 ◽  
Author(s):  
S. Verbanck ◽  
D. Schuermans ◽  
A. Van Muylem ◽  
M. Paiva ◽  
M. Noppen ◽  
...  
Keyword(s):  
Forced Expiratory Volume ◽  
Small Airways ◽  
Ventilation Distribution ◽  
Diffusion Front ◽  
Ventilation Inhomogeneity ◽  
Airway Caliber ◽  
Nonresponder Group ◽  
Multiple Breath Washout ◽  
Significant Change

Verbanck, S., D. Schuermans, A. Van Muylem, M. Paiva, M. Noppen, and W. Vincken. Ventilation distribution during histamine provocation. J. Appl. Physiol. 83(6): 1907–1916, 1997.—We investigated ventilation inhomogeneity during provocation with inhaled histamine in 20 asymptomatic nonsmoking subjects. We used N2multiple-breath washout (MBW) to derive parameters S condand S acin as a measurement of ventilation inhomogeneity in conductive and acinar zones of the lungs, respectively. A 20% decrease of forced expiratory volume in 1 s (FEV1) was used to distinguish responders from nonresponders. In the responder group, average FEV1 decreased by 26%, whereas S condincreased by 390% with no significant change in S acin. In the nonresponder group, FEV1 decreased by 11%, whereas S cond increased by 198% with no significant S acin change. Despite the absence of change in S acin during provocation, baseline S acin was significantly larger in the responder vs. the nonresponder group. The main findings of our study are that during provocation large ventilation inhomogeneities occur, that the small airways affected by the provocation process are situated proximal to the acinar zone where the diffusion front stands, and that, in addition to overall decrease in airway caliber, there is inhomogeneous narrowing of parallel airways.

Letters to the Editor

1998 ◽  
Vol 85 (3) ◽  
pp. 1198-1198 ◽  
Author(s):  
K. I. Gourgoulianis ◽  
P. A. Molyvdas
Keyword(s):  
Forced Expiratory Volume ◽  
Small Airways ◽  
Ventilation Distribution ◽  
Diffusion Front ◽  
Letters To The Editor ◽  
Ventilation Inhomogeneity ◽  
Airway Caliber ◽  
Nonresponder Group ◽  
Multiple Breath Washout ◽  
Significant Change

The following is the abstract of the article discussed in the subsequent letter: Verbanck, S., D. Schuermans, A. Van Muylem, M. Paiva, M. Noppen, and W. Vincken. Ventilation distribution during histamine provocation. J. Appl. Physiol.83(6):1907–1916, 1997.—We investigated ventilation inhomogeneity during provocation with inhaled histamine in 20 asymptomatic nonsmoking subjects. We used N2 multiple-breath washout (MBW) to derive parameters S cond and S acin as a measurement of ventilation inhomogeneity in conductive and acinar zones of the lungs, respectively. A 20% decrease of forced expiratory volume in 1 s (FEV1) was used to distinguish responders from nonresponders. In the responder group, average FEV1decreased by 26%, whereas S cond increased by 390% with no significant change in S acin. In the nonresponder group, FEV1 decreased by 11%, whereas S cond increased by 198% with no significant S acin change. Despite the absence of change in S acin during provocation, baseline S acin was significantly larger in the responder vs. the nonresponder group. The main findings of our study are that during provocation large ventilation inhomogeneities occur, that the small airways affected by the provocation process are situated proximal to the acinar zone where the diffusion front stands, and that, in addition to overall decrease in airway caliber, there is inhomogeneous narrowing of parallel airways.

Multiple-breath washout and washin experiments in steers

1996 ◽  
Vol 81 (2) ◽  
pp. 957-963 ◽  
Author(s):  
F. Rollin ◽  
D. Desmecht ◽  
S. Verbanck ◽  
A. Van Muylem ◽  
P. Lekeux ◽  
...  
Keyword(s):  
Phase Iii ◽  
Slope Ratio ◽  
Ventilation Distribution ◽  
Tidal Breathing ◽  
Ventilation Inhomogeneity ◽  
Multiple Breath Washout ◽  
The Mean ◽  
End Tidal ◽  
Sequential Emptying ◽  
Phase Iii Slope

Multiple-breath N2 washouts (WO) and washins (WI) were performed during regular tidal breathing in 11 unsedated healthy steers approaching pulmonary functional maturity (mean body weight = 271 kg). They inspired 20% O2 in 80% Ar during the WO and air during the WI. For each steer, we computed two indexes of ventilation inhomogeneity from the N2 WO curves: 1) the curvilinearity of the logarithm of end-tidal N2 concentrations as a function of cumulative expired volume reflected in the ratio of two slopes fitted between 100 and 50% and between 50 and 10%, respectively, of end-tidal N2 concentration of the first breath of the WO; and 2) the N2 phase III slope divided by the mean expired concentration (Sn) of each breath also plotted as a function of cumulative expired volume. Equivalent computation of both parameters was done on WI and WO curves, and similar results were obtained. The mean slope ratio was 0.812 +/- 0.119 (SD) for all the steers, which is consistent with topographic gravity-dependent specific ventilation distribution inhomogeneity. Sn was independent of the breath number both for WO and WI (mean Sn = 0.130 +/- 0.057 liters-1), suggesting that emptying between unequally ventilated units, is synchronous. This behavior resembles that observed in rats postmortem (S. Verbanck, E.R. Weibel, and M. Paiva. J. Appl Physiol. 71: 847–854, 1991) but contrasts with experiments in humans, in whom convection-dependent ventilation inhomogeneities generate a marked increase in Sn throughout the entire WO (A. B. H. Crawford, M. Makowska, M. Paiva, and L. A. Engel. J. Appl. Physiol. 59: 838–846, 1985). This is surprising because one would expect gravity-dependent sequential emptying in animals of this size.

scholarly journals Alternative inert gas washout outcomes in patients with primary ciliary dyskinesia

2017 ◽  
Vol 49 (1) ◽  
pp. 1600466 ◽  
Author(s):  
Sylvia Nyilas ◽  
Anne Schlegtendal ◽  
Florian Singer ◽  
Myrofora Goutaki ◽  
Claudia E. Kuehni ◽  
...  
Keyword(s):  
Primary Ciliary Dyskinesia ◽  
Small Airways ◽  
Ventilation Inhomogeneity ◽  
Single Breath ◽  
Promising Tool ◽  
Moment Ratio ◽  
Measurement Duration ◽  
Multiple Breath Washout ◽  
Z Scores ◽  
Ciliary Dyskinesia

The lung clearance index (LCI) derived from a nitrogen multiple breath washout test (N2-MBW) is a promising tool to assess small airways disease in primary ciliary dyskinesia, but it is difficult to apply in routine clinical settings because of its long measuring time. In this study, we aimed to assess alternative indices derived from shorter washout protocols.49 patients with primary ciliary dyskinesia (mean age 14.7±6.6 years) and 37 controls (mean age 14.3±1.4 years) performed N2-MBW and double-tracer gas (DTG) single-breath washout tests. Global (LCI and moment ratio (M2/M0)), conductive (Scond) and acinar ventilation inhomogeneity (DTG Slope III (SIII-DTG)) were determined for each individual. The main outcomes were 1) the ability to detect abnormal lung function from washout indices (>1.64 z-scores) and 2) measurement duration.The prevalence of abnormal values for LCI2.5% was 37 out of 47 (79%), for LCI5% was 34 out of 47 (72%), for M2/M0 was 34 out of 47 (72%), for Scond was 36 out of 46 (78%) and for SIII-DTG was 12 out of 35 (34%). Mean±sd duration of measurement was 19.8±11.2 min for LCI2.5%, 10.8±4.6 min for LCI5% and 8.6±2.3 min for Scond.Compared to standard LCI2.5%, ventilation inhomogeneity was detected by LCI5%, moment ratio and Scond with comparable sensitivity while measurement duration was significantly shorter. Longitudinal studies will show which outcome is most suitable and practical in terms of sensitivity, duration and variability within the course of primary ciliary dyskinesia lung disease.

Lung clearance index: a new measure of ventilation inhomogeneity in childhood respiratory diseases

2021 ◽  
Vol 17 ◽  
Author(s):  
Giuseppe Fabio Parisi ◽  
Emanuela Pignatone ◽  
Maria Papale ◽  
Enza Mulé ◽  
Sara Manti ◽  
...  
Keyword(s):  
Respiratory Diseases ◽  
Small Airways ◽  
Early Assessment ◽  
Lung Clearance ◽  
Ventilation Inhomogeneity ◽  
Lung Clearance Index ◽  
Multiple Breath Washout ◽  
Primary Test ◽  
Forced Breathing

: Conventional spirometry has long been considered the primary test for assessing respiratory function deficits in children and adults. However, the need to perform forced breathing maneuvers can make it challenging to perform these examinations in an uncooperative child. For these reasons, techniques such as gas dilutions and the multiple-breath-washout (MBW) method have been implemented because they allow for early assessment of damage to the small airways. These methods permit the determination of the possible presence of ventilatory inhomogeneity in the lungs by analyzing the clearance of an inert gas used as a tracer. The equipment consists of a mass spectrometer combined with a flow meter. The Lung Clearance Index (LCI) is most often used to evaluate ventilatory inhomogeneity. This narrative review aimed to review the literature on technical and practical aspects of the MBW test and evaluate the clinical implications of the LCI in pediatric respiratory disease.

scholarly journals Asthma in elderly is characterized by increased sputum neutrophils, lower airway caliber variability and air trapping

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
F. Schleich ◽  
S. Graff ◽  
F. Guissard ◽  
M. Henket ◽  
V. Paulus ◽  
...  
Keyword(s):  
Bronchial Hyperresponsiveness ◽  
Forced Expiratory Volume ◽  
Lower Airway ◽  
Low Grade ◽  
Sputum Induction ◽  
Air Trapping ◽  
Cell Counts ◽  
Airway Caliber ◽  
Significant Difference ◽  
Long Acting

Abstract Background Elderly asthmatics represent an important group that is often excluded from clinical studies. In this study we wanted to present characteristics of asthmatics older than 70 years old as compared to younger patients. Methods We conducted a retrospective analysis on a series of 758 asthmatics subdivided in three groups: lower than 40, between 40 and 70 and older than 70. All the patients who had a successful sputum induction were included in the study. Results Older patients had a higher Body Mass Index, had less active smokers and were more often treated with Long Acting anti-Muscarinic Agents. We found a significant increase in sputum neutrophil counts with ageing. There was no significant difference in blood inflammatory cell counts whatever the age group. Forced expiratory volume in one second (FEV1) and FEV1/FVC values were significantly lower in elderly who had lower bronchial hyperresponsiveness and signs of air trapping. We found a lower occurrence of the allergic component in advanced ages. Asthmatics older than 70 years old had later onset of the disease and a significant longer disease duration. Conclusion Our study highlights that asthmatics older than 70 years old have higher bronchial neutrophilic inflammation, a poorer lung function, signs of air trapping and lower airway variability. The role of immunosenescence inducing chronic low-grade inflammation in this asthma subtype remains to be elucidated.

scholarly journals Patterns of regional lung physiology in cystic fibrosis using ventilation magnetic resonance imaging and multiple-breath washout

2018 ◽  
Vol 52 (5) ◽  
pp. 1800821 ◽  
Author(s):  
Laurie J. Smith ◽  
Guilhem J. Collier ◽  
Helen Marshall ◽  
Paul J.C. Hughes ◽  
Alberto M. Biancardi ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cystic Fibrosis ◽  
Total Lung Capacity ◽  
Resonance Imaging ◽  
Ventilation Distribution ◽  
Lung Clearance ◽  
Lung Capacity ◽  
Lung Clearance Index ◽  
Ventilation Heterogeneity ◽  
Multiple Breath Washout

Hyperpolarised helium-3 (3He) ventilation magnetic resonance imaging (MRI) and multiple-breath washout (MBW) are sensitive methods for detecting lung disease in cystic fibrosis (CF). We aimed to explore their relationship across a broad range of CF disease severity and patient age, as well as assess the effect of inhaled lung volume on ventilation distribution.32 children and adults with CF underwent MBW and 3He-MRI at a lung volume of end-inspiratory tidal volume (EIVT). In addition, 28 patients performed 3He-MRI at total lung capacity. 3He-MRI scans were quantitatively analysed for ventilation defect percentage (VDP), ventilation heterogeneity index (VHI) and the number and size of individual contiguous ventilation defects. From MBW, the lung clearance index, convection-dependent ventilation heterogeneity (Scond) and convection–diffusion-dependent ventilation heterogeneity (Sacin) were calculated.VDP and VHI at EIVT strongly correlated with lung clearance index (r=0.89 and r=0.88, respectively), Sacin (r=0.84 and r=0.82, respectively) and forced expiratory volume in 1 s (FEV1) (r=−0.79 and r=−0.78, respectively). Two distinct 3He-MRI patterns were highlighted: patients with abnormal FEV1 had significantly (p<0.001) larger, but fewer, contiguous defects than those with normal FEV1, who tended to have numerous small volume defects. These two MRI patterns were delineated by a VDP of ∼10%. At total lung capacity, when compared to EIVT, VDP and VHI reduced in all subjects (p<0.001), demonstrating improved ventilation distribution and regions of volume-reversible and nonreversible ventilation abnormalities.

Interaction of inhaled LTC4 with histamine and PGD2 on airway caliber in asthma

1989 ◽  
Vol 66 (1) ◽  
pp. 304-312 ◽  
Author(s):  
G. D. Phillips ◽  
S. T. Holgate
Keyword(s):  
Time Course ◽  
Vital Capacity ◽  
Total Lung Capacity ◽  
Forced Expiratory Volume ◽  
Maximal Flow ◽  
Lung Capacity ◽  
Airway Caliber ◽  
Relevant Interaction

To investigate possible mediator interaction in asthma, the effect of inhaled leukotriene (LT) C4 on bronchoconstriction provoked by histamine and prostaglandin (PG) D2 was studied in nine asthmatic subjects. The provocation doses of histamine, PGD2, and LTC4 required to produce a 12.5% decrease in baseline forced expiratory volume in 1 s (FEV1, PD12.5) and to further this fall to 25% (PD25–12.5) were determined. On three subsequent occasions, subjects inhaled either the PD12.5 LTC4 plus vehicle or vehicle plus the PD25–12.5 of either histamine or PGD2, and FEV1 and maximal flow at 70% of vital capacity below total lung capacity after a forced partial expiratory maneuver (Vp30) followed for 45 min. From these results, predicted time-course curves for LTC4 with histamine and LTC4 with PGD2 were calculated. On two final occasions, airway caliber was followed for 45 min after inhalation of the PD12.5 LTC4 followed by the PD25–12.5 of either histamine or PGD2. During the first 9 min after LTC4-histamine and LTC4-PGD2, the decreases in airway caliber were greater than the calculated predicted response. This interaction, although small, was significant with LTC4-PGD2 for both FEV1 (P = 0.01) and Vp30 (P less than 0.05) and with LTC4-histamine for Vp30 (P less than 0.05) but not for FEV1 (P less than 0.05). We conclude that inhaled LTC4 interacts synergistically with histamine and PGD2 and that this effect, although small, may be a relevant interaction in asthma.

Respiratory impedance and multibreath N2 washout in healthy, asthmatic, and cystic fibrosis subjects

1990 ◽  
Vol 68 (5) ◽  
pp. 2139-2149 ◽  
Author(s):  
K. R. Lutchen ◽  
R. H. Habib ◽  
H. L. Dorkin ◽  
M. A. Wall
Keyword(s):  
Cystic Fibrosis ◽  
Normal Subjects ◽  
Forced Expiratory Volume ◽  
The Other ◽  
Poor Correlation ◽  
Base Line ◽  
Respiratory Impedance ◽  
Ventilation Distribution ◽  
Peripheral Airway ◽  
Lung Periphery

We measured forced expiratory volume in 1 s (FEV1), respiratory impedance (Zrs) from 4 to 60 Hz, and a multibreath N2 washout (MBNW) in 6 normal, 10 asthmatic, and 5 cystic fibrosis (CF) subjects. The MBNW were characterized by the mean dilution number (MDN) derived by a moment analysis. The Zrs spectra were characterized by the minimum resistance (Rmin), the drop in resistance (Rdrop) from 4 Hz to Rmin, and the first resonance frequency (Fr1). Measurements were repeated after bronchodilation in three normal and all asthmatic subjects. Before bronchodilation, six of the asthmatic subjects showed close to normal FEV1. The Zrs in the normal subjects showed low Rmin (1.9 +/- 0.7 cmH2O.l-1.s), Rdrop (0.4 +/- 0.4), and Fr1 (10 +/- 2 Hz). Four of the mildly obstructed asthmatic subjects had normal Zrs but elevated MDNs (i.e., abnormal ventilation distribution). The other six asthmatic subjects had significantly elevated Rmin (4.1 +/- 0.8), Rdrop (6.3 +/- 5.8), and Fr1 (34 +/- 0.4 Hz) and elevated MDNs. The CF patients had elevated Zrs features and MDNs. After bronchodilation, no changes in FEV1, MDN, or Zrs occurred in the normal subjects. All asthmatic subjects showed increased FEV1 and decreased MDN, but the Zrs was unaltered in the four asthmatic subjects whose base-line Zrs was normal. For the other six asthmatic subjects, there were large decreases in the Rmin, Rdrop, and Fr1. Finally, there was a poor correlation between the MDN and the Zrs features but high correlation between the Zrs features alone. These results imply that significant nonuniform peripheral airway obstruction can exist such that ventilation distribution is abnormal but Zrs from 4 to 60 Hz is not. Abnormalities in Zrs from 4 to 60 Hz occur only after significant overall obstruction in the peripheral and more central airways. Combining Zrs and the MBNW may permit us to infer whether the disease is predominantly in the lung periphery or in the more central airways.

Does baseline airway caliber affect measurements of airway responsiveness to histamine

1993 ◽  
Vol 74 (6) ◽  
pp. 3034-3039 ◽  
Author(s):  
O. P. Twentyman ◽  
S. V. Hood ◽  
S. T. Holgate
Keyword(s):  
Time Course ◽  
Geometric Mean ◽  
Forced Expiratory Volume ◽  
Airway Responsiveness ◽  
Bronchial Responsiveness ◽  
Subsequent Response ◽  
Airway Caliber ◽  
Before And After ◽  
Airway Response ◽  
Considerable Controversy

Considerable controversy exists over the influence of baseline airway caliber on indexes of bronchial responsiveness in asthma. To directly investigate this, we used inhaled methacholine to alter baseline airway caliber to determine whether this altered the airway response to subsequent bronchoprovocation with inhaled histamine. Seventeen stable asthmatic subjects were studied; their median age was 22 yr, baseline forced expiratory volume in 1 s (FEV1) was 101.5 +/- 3.7% (SE) predicted, and geometric mean provocative concentration of inhaled methacholine causing a 20% fall in FEV1 (PC20) was 0.87 mg/ml. Initially the time course of bronchoconstriction to inhaled methacholine was determined. Subsequently the airway response to inhaled histamine administered as a single concentration was determined, both before and after reductions in baseline FEV1 by saline or methacholine of 0, 15, 25, and 35%, on 4 separate days. Altering baseline airway caliber had no effect on the subsequent response of the airways to inhaled histamine when calculated as percent fall from the new baseline. The power of the study to detect an effect of altering baseline FEV1 on the measured PC20 histamine of 0.5 doubling dilutions was > 55%, and the power to detect an effect of 1.0 doubling dilutions was > 98%.

scholarly journals Potent bronchoprotective effect of deep inspiration and its absence in asthma

2000 ◽  
Vol 89 (2) ◽  
pp. 711-720 ◽  
Author(s):  
Trisevgeni Kapsali ◽  
Solbert Permutt ◽  
Beth Laube ◽  
Nicola Scichilone ◽  
Alkis Togias
Keyword(s):  
Single Dose ◽  
Healthy Subjects ◽  
Alternative Hypothesis ◽  
Forced Expiratory Volume ◽  
Deep Inspiration ◽  
Healthy Individuals ◽  
Lung Inflation ◽  
Airway Caliber ◽  
Physiologic Function ◽  
Rule Out

In the absence of deep inspirations, healthy individuals develop bronchoconstriction with methacholine inhalation. One hypothesis is that deep inspiration results in bronchodilation. In this study, we tested an alternative hypothesis, that deep inspiration acts as a bronchoprotector. Single-dose methacholine bronchoprovocations were performed after 20 min of deep breath inhibition, in nine healthy subjects and in eight asthmatics, to establish the dose that reduces forced expiratory volume in 1 s by >15%. The provocation was repeated with two and five deep inspirations preceding methacholine. Additional studies were carried out to assess optimization and reproducibility of the protocol and to rule out the possibility that bronchoprotection may result from changes in airway geometry or from differential spasmogen deposition. In healthy subjects, five deep inspirations conferred 85% bronchoprotection. The bronchoprotective effect was reproducible and was not attributable to increased airway caliber or to differential deposition of methacholine. Deep inspirations did not protect the bronchi of asthmatics. We demonstrated that bronchoprotection is a potent physiologic function of lung inflation and established its absence, even in mild asthma. This observation deepens our understanding of airway dysfunction in asthma.

Sign in / Sign up

Export Citation Format

Share Document