Related Experiment Videos
Maturational changes of effective elastance in the first 10 days of life
Insights
Respiratory system elastance (E
Area of Science:
- Neonatal Physiology
- Respiratory Mechanics
- Infant Development
Background:
- The effective elastance of the respiratory system (E'rs) quantifies resistance to tidal volume changes under elastic loads.
- Understanding E'rs is crucial for assessing respiratory function in premature infants.
Purpose of the Study:
- To measure E'rs in premature infants of varying gestational ages.
- To investigate the impact of maturation and CO2 levels on E'rs.
- To determine factors influencing maturational changes in E'rs.
Main Methods:
- E'rs was measured in two groups of premature infants at different ages (1 day, 3-4 days, 7-10 days).
- Infants breathed air, 2% CO2 in air, and 4% CO2 in air.
- Measurements were correlated with gestational age and thoracic gas volumes.
Main Results:
- E'rs decreased with increasing infant maturation.
- E'rs remained independent of controlled tidal volume changes.
- Maturational decreases in E'rs were largely explained by changes in thoracic gas volume.
Conclusions:
- Infant size and thoracic gas volume are primary drivers of maturational changes in respiratory elastance.
- The Hering-Breuer reflex activity does not appear to significantly alter these maturational trends.
- These findings enhance our understanding of respiratory adaptation in preterm neonates.
Abstract:
The effective elastance of the respiratory system (E'rs) is a measure of its ability to resist a change in tidal volume under conditions of changing elastic loads. E'rs was measured while subjects breathed air and 2% CO2 and 4% CO2 in air in two groups of premature infants of different gestational ages at 1 day 3-4 days, and 7-10 days of age. E'rs was shown to decrease with increasing maturation and was independent of changes in control tidal volume. The decrease of E'rs with increased gestational age could be accounted for by differences in calculated thoracic gas volumes in all but one instance, where E'rs was lower in one group on the 3rd day of life. The activity of the Hering-Breuer reflex, as measured by the degree of slowing of inspiratory time after occlusion at FRC, has been previously reported to be normal to increased in similar infants. This suggests that differences related to size account for most of the maturational changes of E'rs in newborns.