Biomaterial Database

Intrapulmonary gas distribution in healthy children. 1986

R Kraemer, and M Zehnder, and B Meister

Distribution of ventilation was evaluated in 54 healthy children (24 boys and 30 girls), aged 7-16 years by multibreath nitrogen washout (MBNW) curves, from which the moment ratios (m1: m0, m2: m0), the lung clearance index, the Becklake index and the ventilatory efficiency index (E 90%) was computed. Functional residual capacity (FRC) was calculated from the washout curve and compared with the thoracic gas volume (TGV) plethysmographically determined, as well as with the FRC determined by helium dilution. The study shows that MBNW can easily be performed during spontaneous breathing in children and provides specific indices of ventilation. These indices show no sex difference and are age-independent. Therefore, the data of the present study contradict some previous indirect findings suggesting that the distribution of air in the lungs would become more even with age. There are in contrast more convincing direct measurement data showing that airways grow isotropically relative to the lungs.

UI	MeSH Term	Description	Entries
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D008176	Lung Volume Measurements	Measurement of the amount of air that the lungs may contain at various points in the respiratory cycle.	Lung Capacities,Lung Volumes,Capacity, Lung,Lung Capacity,Lung Volume,Lung Volume Measurement,Measurement, Lung Volume,Volume, Lung
D008297	Male		Males
D009584	Nitrogen	An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.
D010993	Plethysmography, Whole Body	Measurement of the volume of gas in the lungs, including that which is trapped in poorly communicating air spaces. It is of particular use in chronic obstructive pulmonary disease and emphysema. (Segen, Dictionary of Modern Medicine, 1992)	Whole Body Plethysmography,Body Plethysmographies, Whole,Body Plethysmography, Whole,Plethysmographies, Whole Body,Whole Body Plethysmographies
D012044	Regression Analysis	Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.	Regression Diagnostics,Statistical Regression,Analysis, Regression,Analyses, Regression,Diagnostics, Regression,Regression Analyses,Regression, Statistical,Regressions, Statistical,Statistical Regressions
D012115	Residual Volume	The volume of air remaining in the LUNGS at the end of a maximal expiration. Common abbreviation is RV.	Residual Volumes,Volume, Residual,Volumes, Residual
D012119	Respiration	The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (	Breathing
D002648	Child	A person 6 to 12 years of age. An individual 2 to 5 years old is CHILD, PRESCHOOL.	Children
D005069	Evaluation Studies as Topic	Works about studies that determine the effectiveness or value of processes, personnel, and equipment, or the material on conducting such studies.	Critique,Evaluation Indexes,Evaluation Methodology,Evaluation Report,Evaluation Research,Methodology, Evaluation,Pre-Post Tests,Qualitative Evaluation,Quantitative Evaluation,Theoretical Effectiveness,Use-Effectiveness,Critiques,Effectiveness, Theoretical,Evaluation Methodologies,Evaluation Reports,Evaluation, Qualitative,Evaluation, Quantitative,Evaluations, Qualitative,Evaluations, Quantitative,Indexes, Evaluation,Methodologies, Evaluation,Pre Post Tests,Pre-Post Test,Qualitative Evaluations,Quantitative Evaluations,Report, Evaluation,Reports, Evaluation,Research, Evaluation,Test, Pre-Post,Tests, Pre-Post,Use Effectiveness