Evaluation of Reproducibility of a Multibreath Nitrogen Washout Test in Normal Subjects1

2015 ◽  
pp. 138-140
Author(s):  
F. Cibella ◽  
A. Mangiacavallo ◽  
P. Pipitone ◽  
C. Macaluso ◽  
G. Bonsignore
Keyword(s):  
Nitrogen Washout

Moment ratio analysis of multiple breath nitrogen washout in infants with lung disease

2000 ◽  
Vol 15 (6) ◽  
pp. 1094 ◽  
Author(s):  
A. Schibler ◽  
M. Schneider ◽  
U. Frey ◽  
R. Kraemer
Keyword(s):  
Lung Disease ◽  
Ratio Analysis ◽  
Nitrogen Washout ◽  
Moment Ratio

Computerized single-breath nitrogen washout: Predicted values in a rural French community

Lung ◽  
2004 ◽  
Vol 174 (1) ◽  
Author(s):  
D.B. Teculescu ◽  
M.-C. Daniel ◽  
E. Costantino ◽  
O. Buhler ◽  
A.B. Bohadana ◽  
...  
Keyword(s):  
Nitrogen Washout ◽  
Single Breath ◽  
Predicted Values

Chronic Pulmonary Disease in Neonates After Artificial Ventilation: Distribution of Ventilation and Pulmonary Interstitial Emphysema

PEDIATRICS ◽  
1977 ◽  
Vol 60 (3) ◽  
pp. 273-281
Author(s):  
John L. Watts ◽  
Ronald L. Ariagno ◽  
June P. Brady
Keyword(s):  
Ductus Arteriosus ◽  
Ventilation Distribution ◽  
Pulmonary Interstitial Emphysema ◽  
Interstitial Emphysema ◽  
Nitrogen Washout ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
Inspired Oxygen ◽  
Measured Distribution

To determine pulmonary function abnormalities in patients with neonatal bronchopulmonary dysplasia (BPD), we measured distribution of ventilation by nitrogen washout, minute and tidal volume, and arterial and alveolar gases in three groups of ten preterm infants with similar birth weights (mean = 1,340 g) and gestational ages (mean = 30.3 weeks). Infants in group A were never artificially ventilated, those in group B were ventilated but had no subsequent BPD, and those in group C were ventilated and developed BPD. Infants with BPD had severe maldistribution of ventilation (pulmonary clearance delay 223% versus 47% and 60% for groups A and B). They had decreased tidal volumes (5.3 ml versus 7.0 and 6.2 ml) and higher respiratory rates (60/min versus 47 and 48) but similar minute volumes. They also had increased Paco2 (53.6 torr versus 41.9 and 43.4 torr) and increased arterial-alveolar carbon dioxide gradients (6.8 torr versus 3.1 and 1.8 torr). There was no statistically significant difference between groups B and C for the time spent in fractional inspired oxygen > 0.40 and > 0.60, or the time ventilated or intubated, or the incidence of patent ductus arteriosus. Early pulmonary interstitial emphysema was much more common in the infants who subsequently developed BPD (eight of ten versus two of ten, P < .01).

Inflection point on transpulmonary pressure-volume curves and closing volume

1975 ◽  
Vol 38 (2) ◽  
pp. 228-235 ◽  
Author(s):  
M. Demedts ◽  
J. Clement ◽  
D. C. Stanescu ◽  
K. P. van de Woestijne
Keyword(s):  
Inflection Point ◽  
Vital Capacity ◽  
Transpulmonary Pressure ◽  
Bronchial Obstruction ◽  
Closing Volume ◽  
Lung Volumes ◽  
Nitrogen Washout ◽  
Single Breath ◽  
Space Effect ◽  
Washout Curves

In 20 healthy subjects and 18 patients with bronchial obstruction, closing volume (CV) on single-breath nitrogen washout curves and inflection point (IP) on transpulmonary pressure-volume curves were recorded simultaneously during slow expiratory vital capacity maneuvers. IP and CV did not occur at identical lung volumes, IP being systematically larger than CV for small CV values. This discrepancy could not be attributed to an esophageal or mediastinal artifact. It is suggested that, though CV and IP both express “airway closure,” their sensitivity to closure may differ: CV underestimates closure because of a dead space effect; the latter may vary individually. On the other hand, IP may not reflect the true beginning of closure, particularly when it occurs at higher lung volumes.

scholarly journals Better late than never: correcting the error in the Exhalyzer nitrogen washout system

2021 ◽  
Vol 131 (4) ◽  
pp. 1286-1287
Author(s):  
Alexander Horsley ◽  
Chantal Darquenne
Keyword(s):  
Nitrogen Washout

scholarly journals Bronchial thermoplasty reduces ventilation heterogeneity measured by multiple breath nitrogen washout

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
David Langton ◽  
Kim Bennetts ◽  
Francis Thien ◽  
Virginia Plummer ◽  
Peter B. Noble
Keyword(s):  
Clinical Benefit ◽  
Left Lung ◽  
Ct Scanning ◽  
Beta Agonist ◽  
Oral Steroid ◽  
Asthma Control Questionnaire ◽  
Nitrogen Washout ◽  
Lung Physiology ◽  
Bronchial Thermoplasty ◽  
Ct Evaluation

Abstract Background Despite demonstrated symptomatic benefit from bronchial thermoplasty (BT), the underlying pathophysiological benefits have been uncertain. The purpose of the present study was to relate clinical benefit after BT to changes in lung physiology, focusing on ventilation homogeneity assessed using multiple breath nitrogen washout (MBNW), and how this may be affected by changes in airway volume and resistance. Methods Consecutive patients (n = 21) with severe asthma scheduled for BT, were evaluated at baseline, 6 weeks and 6 months after completion of treatment. Assessments included the Asthma Control Questionnaire (ACQ), medication usage, exacerbation frequency, spirometry, plethysmography and MBNW. Eighteen of these patients underwent detailed CT evaluation for the estimation of airway volume at baseline and then after the left lung had received BT treatment but prior to right lung treatment. Data are mean ± STDEV. Results Patients responded to BT with an improvement in ACQ from 3.4 ± 0.8 at baseline to 2.0 ± 1.1 at 6 months (p < 0.001). Steroid requiring exacerbations fell from 3.1 ± 2.9 in the 6 months prior to BT to 1.4 ± 1.7 following BT (p < 0.001). Significant reductions in maintenance oral steroid dosing and short acting beta agonist use were observed. Airway volume measured by CT scanning significantly increased after treatment. The FEV1 improved from 1.34 ± 0.65 l to 1.52 ± 0.76 l (p = 0.024). The Residual Volume fell from 2.87 ± 0.89 l to 2.71 ± 0.93 l (p = 0.008) and Total Airway Resistance (Raw) from 10.58 ± 6.56 to 7.64 ± 3.74 cmH2O.s.l−1 (p = 0.020). The Lung Clearance Index (LCI) was 187 ± 63% predicted at baseline and improved after treatment from 12.7 ± 3.3 to 11.8 ± 2.4 (p = 0.049). The improvement in LCI correlated with the improvement in Raw (r = 0.463, p = 0.035). Conclusion Clinical benefit after BT is accompanied by improvements in lung physiology, including normalisation of lung homogeneity that seems to be driven by airway dilation and reduced resistance.

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