A Single Breath Method to Assess the Relative Contribution of Central and Peripheral Airways to Overall Exhaled Breath Temperature

2015 ◽  
Vol 135 (2) ◽  
pp. AB177 ◽  
Author(s):  
Todor A. Popov ◽  
Diana Hristova ◽  
Tanya Kralimarkova ◽  
Dimitar Popov ◽  
Andrey Popov ◽  
...  
Keyword(s):  
Exhaled Breath ◽  
Peripheral Airways ◽  
Single Breath ◽  
Relative Contribution ◽  
Single Breath Method

Respiratory physiology teaching: determination of residual volume by applying the indicator-dilution technique.

1998 ◽  
Vol 274 (6) ◽  
pp. S53
Author(s):  
H Heller ◽  
K Granitza ◽  
B Eixmann
Keyword(s):  
Indicator Dilution ◽  
Respiratory Physiology ◽  
Successful Outcome ◽  
Residual Volume ◽  
Dilution Technique ◽  
Laboratory Courses ◽  
Single Breath ◽  
Indicator Dilution Technique ◽  
Single Breath Method

Apart from the current teaching of spirometric methods in laboratory courses on respiratory physiology, we have included an experiment in which medical students determine their own residual volume by applying the indicator-dilution technique. For hygienic reasons we used a bag-in-the-box system to dilute helium within alveolar space by performing the single-breath method. Although each participant independently underwent only one single-breath maneuver, we gained a reliable relationship between residual volume and subjects' height and body weight in 68 female (r = 0.6, P < 0.0001) and 99 male (r = 0.42, P < 0.0001) students. From this successful outcome and with the opportunity to discuss the limitations of the single-breath method as well, we inferred that this experiment affords a transparent and instructive approach to interpreting the determination of lung volumes on the basis of the indicator-dilution technique.

Inhomogeneity of pulmonary ventilation during sustained microgravity as determined by single-breath washouts

1994 ◽  
Vol 76 (4) ◽  
pp. 1719-1729 ◽  
Author(s):  
H. J. Guy ◽  
G. K. Prisk ◽  
A. R. Elliott ◽  
R. A. Deutschman ◽  
J. B. West
Keyword(s):  
Vital Capacity ◽  
Normal Gravity ◽  
Parabolic Flight ◽  
Pulmonary Ventilation ◽  
Phase Iii ◽  
Single Breath ◽  
Relative Contribution ◽  
Cardiogenic Oscillations ◽  
Expiratory Flow Rates ◽  
Phase Iv

Gravity is known to cause inhomogeneity of ventilation. Nongravitational factors are also recognized, but their relative contribution is not understood. We therefore studied ventilatory inhomogeneity during sustained microgravity during the 9-day flight of Spacelab SLS-1. All seven crew members performed single-breath nitrogen washouts. They inspired a vital capacity breath of 100% oxygen with a bolus of argon at the start of inspiration, and the inspiratory and expiratory flow rates were controlled at 0.5 l/s. Control measurements in normal gravity (1 G) were made pre- and postflight in the standing and supine position. Compared with the standing 1-G measurements, there was a marked decrease in ventilatory inhomogeneity during microgravity, as evidenced by the significant reductions in cardiogenic oscillations, slope of phase III, and height of phase IV for nitrogen and argon. However, argon phase IV volume was not reduced, and considerable ventilatory inhomogeneity remained. For example, the heights of the cardiogenic oscillations during microgravity for nitrogen and argon were 44 and 24%, respectively, of their values at 1 G, whereas the slopes of phase III for nitrogen and argon were 78 and 29%, respectively, of those at 1 G. The presence of a phase IV in microgravity is strong evidence that airway closure still occurs in the absence of gravity. The results were qualitatively similar to those found previously during short periods of 0 G in parabolic flight.

scholarly journals Advances in Mid-Infrared Spectroscopy-Based Sensing Techniques for Exhaled Breath Diagnostics

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2227 ◽  
Author(s):  
Ramya Selvaraj ◽  
Nilesh J. Vasa ◽  
S. M. Shiva Nagendra ◽  
Boris Mizaikoff
Keyword(s):  
Point Of Care ◽  
High Sensitivity ◽  
Special Focus ◽  
Exhaled Breath ◽  
Biomarker Detection ◽  
Mid Infrared ◽  
Optical Instruments ◽  
Single Breath ◽  
Volatile Organic ◽  
Recent Developments

Human exhaled breath consists of more than 3000 volatile organic compounds, many of which are relevant biomarkers for various diseases. Although gas chromatography has been the gold standard for volatile organic compound (VOC) detection in exhaled breath, recent developments in mid-infrared (MIR) laser spectroscopy have led to the promise of compact point-of-care (POC) optical instruments enabling even single breath diagnostics. In this review, we discuss the evolution of MIR sensing technologies with a special focus on photoacoustic spectroscopy, and its application in exhaled breath biomarker detection. While mid-infrared point-of-care instrumentation promises high sensitivity and inherent molecular selectivity, the lack of standardization of the various techniques has to be overcome for translating these techniques into more widespread real-time clinical use.

scholarly journals Changes in Lung Diffusing Capacity of Elite Artistic Swimmers During Training

2020 ◽  
Author(s):  
Iker García ◽  
Franchek Drobnic ◽  
Victoria Pons ◽  
Ginés Viscor
Keyword(s):  
Carbon Monoxide ◽  
Repeated Measures ◽  
Significant Interaction ◽  
Physiological Responses ◽  
Individual Variability ◽  
Diffusing Capacity ◽  
Repeated Measures Anova ◽  
National Team ◽  
Single Breath ◽  
Single Breath Method

AbstractArtistic swimmers (AS) are exposed to repeated apnoeas in the aquatic environment during high intensity exercise provoking specific physiological responses to training, apnoea, and immersion. This study aimed to evaluate the changes in lung diffusing capacity in AS pre-, mid- and post-training in a combined session of apnoeic swimming, figures and choreography. Eleven elite female AS from the Spanish national team were the study’s participants. The single-breath method was used to measure lung diffusing capacity for carbon monoxide (DLCO) and one-way repeated measures ANOVA was utilized to evaluate the statistical analysis. Basal values of DLCO were higher than normal for their age and height (33.6±4.9 mL·min−1·mmHg−1; 139±19%) and there were a significant interaction between DLCO and AS training (ŋ2 p=0.547). After the apnoeic swimming (mid-training) there was an increase in DLCO from basal to 36.7±7.3 mL·min−1·mmHg−1 (p=0.021), and after the figures and choreography (post-training) there was a decrease compared to mid-training (32.3±4.6 mL·min−1·mmHg−1, p=0.013). Lung diffusing capacity changes occur during AS training, including a large increase after apnoeic swimming. There were no differences in lung diffusing capacity from pre- to post-training, although large inter-individual variability was observed.

Single-breath nitrogen test in excised human lungs

1981 ◽  
Vol 51 (6) ◽  
pp. 1568-1573 ◽  
Author(s):  
N. Berend ◽  
C. Skoog ◽  
W. M. Thurlbeck
Keyword(s):  
Transpulmonary Pressure ◽  
Phase Iii ◽  
Peripheral Airways ◽  
Single Breath ◽  
Human Lungs ◽  
Peripheral Airway ◽  
Normal Lungs ◽  
Airway Dimensions ◽  
Phase Iv

Pressure-volume curves and simulated single-breath nitrogen tests were performed on 32 excised left human lungs and the slope of phase III, and phase IV plus minimal volume, expressed as percent of the lung volume at a transpulmonary pressure of 30 cmH2O (closing capacity), was calculated. The lungs were graded as to the degree of emphysema and degree of peripheral airways disease. Peripheral airway dimensions were also measured. The closing capacity expressed as percent predicted in vivo was significantly correlated with the total pathological scores (P less than 0.01) and inflammation scores (P less than 0.01) as well as the transpulmonary pressures at the onset of phase IV (P less than 0.01). Correlations with the emphysema grade were not significant. The slopes of phase III were highly variable even among normal lungs and could not be shown to correlate with airways disease or emphysema.

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