A prospective observational study comparing the developmental changes in work of breathing indices and oxygen saturation of term and preterm infants at birth. Do premature infants compensate?

Abstract

Background

Intrauterine lung development is a complex process. Little is known regarding developmental breathing patterns of infants from delivery to discharge. In this study, we analyze developmental changes in work of breathing indices and oxygen saturation between healthy preterm and term infants at discharge.

Methods

A prospective, observational study of healthy term infants at a single center nursery. Respiratory Inductive Plethysmography and pulse oximetry were studied in the supine position, between 12 and 48 h of birth. Comparative analysis was performed with data from our study of premature infants without BPD.

Results

The study included 63 infants (32 premature and 31 full term). Work of breathing was increased in term infants compared to preterm infants at discharge (Mean phase-angle, Φ ± SEM; Term: 73 ± 5° vs Preterm: 49 ± 7°; p = 0.017). Term infants had lower mean oxygen saturation (Term: 95 ± 0.42% vs Preterm: 97 ± 0.32%; p < 0.001), respiratory rate (Term: 56 ± 2.99 br/min vs Preterm: 67 ± 2.55 br/min; p < 0.008), and heart rate (Term: 130 ± 2.4 bpm vs Preterm: 158 ± 1.8 bpm; p < 0.0001) compared to preterm infants at discharge.

Conclusion

Preterm infants at discharge demonstrated more efficient thoracoabdominal synchrony and higher oxygen saturation than term infants. These findings suggest that preterm infants develop adaptive respiratory strategies in response to early and prolonged extrauterine respiratory demands, which confer physiological advantages despite structural immaturity. The data could influence post-discharge monitoring of preterm infants.