Voluntary changes in breathing pattern and N2 clearance from lungs

1961 ◽  
Vol 16 (6) ◽  
pp. 1039-1042 ◽  
Author(s):  
Arend Bouhuys ◽  
Stefan Lichtneckert ◽  
Claes Lundgren ◽  
Gunnar Lundin
Keyword(s):  
Breathing Pattern ◽  
Practical Importance ◽  
Lung Ventilation ◽  
Breathing Rate ◽  
Gas Distribution ◽  
Lung Clearance ◽  
Lung Clearance Index ◽  
Dead Space Volume ◽  
Active Substances ◽  
Space Volume

Lung N2 clearance curves were recorded in three normal and two symptom-free asthmatic subjects at breathing rates of 10—60/min and tidal volumes of 350—1,950 ml. A change toward more uniform gas distribution at larger tidal volumes was found in one subject. Changes in breathing rate did not affect gas distribution demonstrably. The washout ventilation per liter lung volume (lung clearance index) did not show significant changes with either breathing rate or tidal volume except for an increase at tidal volumes of less than 450 ml. These findings agree with the assumption of a constant dead space volume at tidal volumes within the range studied. The results are of practical importance for the use of the lung clearance index as a measure of the effect of broncho-active substances on the lung ventilation in man. Submitted on April 28, 1961

scholarly journals The effect of inert gas choice on multiple breath washout in healthy infants: differences in lung function outcomes and breathing pattern

2017 ◽  
Vol 123 (6) ◽  
pp. 1545-1554 ◽  
Author(s):  
Per M. Gustafsson ◽  
Lovisa Bengtsson ◽  
Anders Lindblad ◽  
Paul D. Robinson
Keyword(s):  
Functional Residual Capacity ◽  
Sulfur Hexafluoride ◽  
Breathing Pattern ◽  
Inert Gas ◽  
Respiratory Drive ◽  
Quiet Sleep ◽  
Lung Clearance ◽  
Healthy Infants ◽  
Lung Clearance Index ◽  
Residual Capacity

The detrimental effects on breathing pattern during multiple breath inert gas washout (MBW) have been described with different inhaled gases [100% oxygen (O2) and sulfur hexafluoride (SF6)] but detailed comparisons are lacking. N2- and SF6-based tests were performed during spontaneous quiet sleep in 10 healthy infants aged 0.7–1.3 yr using identical hardware. Differences in breathing pattern pre and post 100% O2 and 4% SF6 exposure were investigated, and the results obtained were compared [functional residual capacity (FRC) and lung clearance index (LCI)]. During 100% O2 exposure. mean inspiratory flow (“respiratory drive”) decreased transiently by mean (SD) 28 (9)% ( P < 0.001), and end-tidal CO2 (carbon dioxide) increased by mean (SD) 0.3 (0.4)% units ( P < 0.05) vs. air breathing prephase. During subsequent N2 washin (i.e., recovery phase), the pattern of change reversed. No significant effect on breathing pattern was observed during SF6 testing. In vitro testing confirmed that technical artifacts did not explain these changes. Mean (SD) FRC and LCI in vivo were significantly higher with N2 vs. SF6 washout: 216 (33) vs. 186 (22) ml ( P < 0.001) and 8.25 (0.85) vs. 7.55 (0.57) turnovers ( P = 0.021). Based on these results, SF6 based MBW is the preferred methodology for tests in this age range. NEW & NOTEWORTHY Inert gas choice for multiple breath inert gas washout (MBW) in infants has important consequences on both breathing pattern during test performance and the functional residual capacity and lung clearance index values obtained. Data suggest the detrimental effect of breathing pattern of 100% O2 and movement of O2 across the alveolar capillary membrane, with direct effects on MBW outcomes. SF6 MBW during infancy avoids this and can be further optimized by addressing the sources of technical artifact identified in this work.

Distribution of ventilation in normal subjects from 7 to 45 years of age

1965 ◽  
Vol 20 (1) ◽  
pp. 77-78 ◽  
Author(s):  
M. M. Orzalesi ◽  
M. C. Hart ◽  
C. D. Cook
Keyword(s):  
Normal Values ◽  
Normal Subjects ◽  
Gas Distribution ◽  
Lung Clearance ◽  
Nitrogen Washout ◽  
Lung Clearance Index ◽  
Age Dependent

Distribution of ventilation was investigated in 57 normal subjects of both sexes ranging in age from 7 to 45 years using the nitrogen washout method. Normal values for nitrogen clearance delay and the lung clearance index are presented for children and adults. No significant sex- or age-dependent difference was found in either of these parameters. The present data are compared with those in the literature. nitrogen washout; respiration in children and adults; distribution of inspired gas in children and adults; gas distribution Submitted on April 13, 1964

Effect of body posture on gas distribution in the lungs

1962 ◽  
Vol 17 (1) ◽  
pp. 38-42 ◽  
Author(s):  
Arend Bouhuys ◽  
Hans J. van Lennep
Keyword(s):  
Normal Subjects ◽  
Gas Distribution ◽  
Lung Clearance ◽  
Postural Changes ◽  
Lung Clearance Index ◽  
Residual Capacity ◽  
Mechanical Factors ◽  
Male Subjects ◽  
Tilting Table ◽  
Volume Decrease

Postural changes of functional residual capacity (FRC) and pulmonary N2 clearance efficiency were studied in six male subjects placed supine on a tilting table, in head-up, horizontal and head-down positions. FRC varied linearly with the angle of tilt. The lung clearance index (LCI) increased significantly in the supine and head-down positions, compared to the head-up positions, which indicates less uniform gas distribution in the former postures. This was confirmed by analysis of semilogarithmic graphs of N2 washout. Inhalation of epinephrine did not affect the postural changes of FRC and LCI, but caused a small increase of LCI irrespective of posture. The increased uneven distribution in head-down and supine positions is probably a consequence of the lung volume decrease in these postures, and may be explained by mechanical factors such as surface tension, which tend to close lung units when the lungs are deflated. Bronchomotor tone has no appreciable influence on these postural changes in normal subjects. Submitted on July 13, 1961

scholarly journals Volumetric Сapnography As a Tool for Evaluation of Alveolar Ventilation Effectiveness in Clinical Practice

2018 ◽  
Vol 14 (5) ◽  
pp. 16-24 ◽  
Author(s):  
P. Török ◽  
F. Depta ◽  
V. Donic ◽  
M. Nosál’ ◽  
S. Imrecze ◽  
...  
Keyword(s):  
Minute Ventilation ◽  
Artery Bypass ◽  
Lung Ventilation ◽  
Co2 Exchange ◽  
Alveolar Ventilation ◽  
Co2 Production ◽  
Dead Space Volume ◽  
The Relationship ◽  
Pressure Controlled ◽  
Space Volume

The purpose of the study was to compare the relationship between the dead space volume and tidal volume (VD/VT) using volumetric capnography (VCap) during pressure controlled (PCV) and pressure supported (PSV) ventilation mode in the postoperative period.Materials and methods. 30 randomly assigned cardiac surgical patients undergoing CABG (coronary artery bypass grafting) using ECC (extracorporeal circuit) were included in an observational, prospective study. Patients were connected to the ventilator immediately after ICU admission. After that, monitoring VD/VT, CO2 production (VECO2) as well as ventilation parameters was carried out. The parameters during PCV and PSV mode were statistically evaluated using t-test.Results. Expiratory CO2 (ETCO2) concentration were not significantly different in both PCV or PSV (p=NS), although both VECO2 and minute ventilation (MV) increased during PSV mode (p<0.01). VD/VT in PSV mode was lower than in PCV. Gas exchange represented by alveolar ventilation (VA) was better during PSV (p<0.01). VA was also higher during PSV (p<0.05). The calculated VD/VT ratio differed between PCV and PSV mode (p<0.01).Conclusion. VCap represents a tool for monitoring of CO2 exchange effectivness. We registered a decrease in VD/VT with improved alveolar ventilation (VA) in PSV mode. VCap seems to be a suitable instrument for adjustment of protective lung ventilation.

Der Lung Clearance Index ist bei Patienten mit COPD erhöht

Pneumologie ◽  
2015 ◽  
Vol 69 (S 01) ◽  
Author(s):  
S Fähndrich ◽  
M Seibert ◽  
C Buess ◽  
PM Lepper ◽  
H Wilkens ◽  
...  
Keyword(s):  
Lung Clearance ◽  
Lung Clearance Index

scholarly journals Ventilation heterogeneity in children with severe asthma

2021 ◽  
Author(s):  
Amy G. Nuttall ◽  
Caroline S. Beardsmore ◽  
Erol A. Gaillard
Keyword(s):  
Severe Asthma ◽  
Airway Disease ◽  
Asthma Severity ◽  
Small Airway ◽  
Cross Sectional ◽  
Lung Clearance ◽  
Moderate Asthma ◽  
Lung Clearance Index ◽  
Children With Asthma ◽  
Ventilation Heterogeneity

AbstractSmall airway disease, characterised by ventilation heterogeneity (VH), is present in a subgroup of patients with asthma. Ventilation heterogeneity can be measured using multiple breath washout testing. Few studies have been reported in children. We studied the relationship between VH, asthma severity, and spirometry in a cross-sectional observational cohort study involving children with stable mild-moderate and severe asthma by GINA classification and a group of healthy controls. Thirty-seven participants aged 5–16 years completed multiple breath nitrogen washout (MBNW) testing (seven controls, seven mild-moderate asthma, 23 severe asthma). The lung clearance index (LCI) was normal in control and mild-moderate asthmatics. LCI was abnormal in 5/23 (21%) of severe asthmatics. The LCI negatively correlated with FEV1z-score.Conclusion: VH is present in asthmatic children and appears to be more common in severe asthma. The LCI was significantly higher in the cohort of children with severe asthma, despite no difference in FEV1 between the groups. This supports previous evidence that LCI is a more sensitive marker of airway disease than FEV1. MBNW shows potential as a useful tool to assess children with severe asthma and may help inform clinical decisions. What is Known:• Increased ventilation heterogeneity is present in some children with asthma• Spirometry is not sensitive enough to detect small airway involvement in asthma What is New• Lung clearance index is abnormal in a significant subgroup of children with severe asthma but rarely in children with mild-moderate asthma• Our data suggests that LCI monitoring should be considered in children with severe asthma

scholarly journals P82 Lung clearance index (LCI) and genotype-phenotype correlations in Primary Ciliary Dyskinesia (PCD)

Thorax ◽  
2015 ◽  
Vol 70 (Suppl 3) ◽  
pp. A116.2-A117
Author(s):  
S Irving ◽  
M Dixon ◽  
S Ollosson ◽  
C Hogg ◽  
A Shoemark ◽  
...  
Keyword(s):  
Primary Ciliary Dyskinesia ◽  
Lung Clearance ◽  
Lung Clearance Index ◽  
Ciliary Dyskinesia
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