Related Experiment Videos
Respiratory input and transfer impedances in children 9-13 years old
Insights
This study establishes reference values for respiratory impedance in healthy children aged 9-13. Respiratory resistance, elastance, and inertance are correlated with height and age, providing crucial data for pediatric respiratory assessments.
Area of Science:
- Pediatric Pulmonology
- Respiratory Physiology
- Biophysics
Background:
- Limited reference values exist for respiratory impedance in children.
- Previous studies focused on mouth-generated pressure inputs, neglecting chest-wall inputs.
Purpose of the Study:
- To establish reference values for total respiratory impedance in healthy children.
- To investigate the correlation of respiratory impedance parameters with biometric variables (height, age).
- To compare respiratory impedance between children from polluted and non-polluted environments.
Main Methods:
- Measured total respiratory impedance (input and transfer) from 4-30 Hz in 69 healthy children (9-13 years).
- Characterized impedance using parameters: resistance (R), low-frequency resistance limit (R0, R0'), slope (S, S'), elastance (E), and inertance (I).
- Correlated impedance parameters with body height and age; compared children from different pollution levels.
Main Results:
- Respiratory resistance (R, R0, R0') significantly correlated with height and age.
- Elastance (E) showed a stronger correlation with height, while inertance (I) correlated better with age.
- No significant differences in most parameters between polluted and non-polluted areas, except for a lower slope of resistance (S) in the polluted group.
Conclusions:
- Developed predictive equations for respiratory resistance, elastance, and inertance based on height and age in children.
- Findings provide essential reference data for pediatric respiratory function assessment.
- Environmental pollution may influence respiratory system dynamics, indicated by altered resistance slope.
Abstract:
Reference values for respiratory impedances in children are scarce and limited to the situation where pressure is varied at the mouth. Total respiratory impedance was therefore measured from 4 to 30 Hz in 69 healthy children (9-13 yr) with both a pressure input at the mouth (input impedance, Zin) and a pressure input at the chest (transfer impedance, Ztr). Zin was characterized by the average resistance (R), the low-frequency limit of resistance (R0), the slope of the resistance-frequency curve (S), respiratory elastance (E) and respiratory inertance (I). Similar coefficients (R0', S', E', I'), some of which however have slightly different physiological meanings, were derived from Ztr. R, R0 and R0' were found to be significantly correlated to body height (p less than 0.001) and, independently, to age (p less than 0.05): R (kPa X l-1 X s) = 1.76-5.29 10(-3) height (cm) -4.13 10(-2) age (yr). Elastances were better correlated to height than to age: E (kPa X l-1) = 20.95-0.101 height (cm) and inertances better correlated to age than to height: I (Pa X l-1 X s2) = 4.39-0.128 age (yr). S and S' were not correlated to biometric variables. No difference was found between children living in polluted (n = 36) and nonpolluted (n = 33) areas, except for S which was significantly lower in the first group (p less than 0.01).