Related Experiment Videos
Development of stability of the respiratory system in preterm infants
1Department of Pediatrics, University of California, San Diego 92103.
Insights
Chest wall distortion impacts preterm infants, increasing diaphragmatic work and displacement. As infants mature, chest wall stability improves, reducing diaphragmatic workload and enhancing lung function.
Area of Science:
- Neonatal Physiology
- Respiratory Mechanics
Background:
- Chest wall distortion is a known factor affecting respiratory function in preterm infants.
- Increased diaphragmatic work and minute volume displacement of the diaphragm (MVDD) are associated with chest wall instability.
Purpose of the Study:
- To investigate the changes in diaphragmatic function and lung mechanics in preterm infants as they mature.
- To correlate changes in diaphragmatic function with chest wall stability and the resolution of apnea of prematurity.
Main Methods:
- Measurements of lung mechanics, MVDD, and diaphragmatic work (DW) were taken weekly in six preterm infants.
- Infants were studied between 29 and 36 weeks postconceptional age.
Main Results:
- MVDD and DW significantly decreased over the study period.
- Dynamic lung compliance showed a consistent increase.
- No significant changes were observed in pulmonary ventilation, total pulmonary resistance, work of the lungs, or intraesophageal pressure changes.
Conclusions:
- Improved chest wall stability in preterm infants is associated with decreased MVDD and DW.
- These improvements in diaphragmatic function parallel the resolution of apnea of prematurity and decreased static chest wall compliance.
Abstract:
Chest wall distortion leads to increased minute volume displacement of the diaphragm (MVDD) and diaphragmatic work (DW) in preterm infants. Lung mechanics, MVDD, and DW were measured at weekly intervals in six preterm infants between 29 and 36 wk postconceptional age. Over the period of study, MVDD and DW decreased significantly, whereas dynamic lung compliance consistently increased. There was no consistent change in the pulmonary ventilation, total pulmonary resistance, the work performed on the lungs, or the change in intraesophageal pressure with tidal breathing. The improvement in the stability of the chest wall, as indicated by the change in these dynamic measurements of diaphragmatic function, parallels the decrease in static chest wall compliance and the clinical course of the resolution of apnea of prematurity.