Intra-breath respiratory oscillometry in the first days of life in preterm infants: a prospective observational study.

We aimed to describe intra-breath changes in respiratory system resistance (Rrs) and reactance (Xrs) in preterm infants receiving non-invasive respiratory support during the first days of life. This prospective observational study included infants born at < 32 weeks' gestation. Respiratory oscillometry was performed at 24-48 h of life using a ventilator that superimposed sinusoidal oscillations (10 Hz) on a continuous positive airway pressure of 5 cmH

conclusionPreterm infants exhibit changes in intra-breath oscillatory mechanics, especially at low gestational age. The reduction in Xrs during expiration is associated with reduced lung compliance and may reflect compensatory mechanisms that elevate end-expiratory lung volume. WHAT IS KNOWN: • Intra-breath changes in oscillatory mechanics have been used to reveal disease-specific pathophysiological behaviours in other age groups. WHAT IS NEW: • This study shows that intra-tidal changes in oscillatory mechanics are present in preterm infants on nasal continuous positive airway pressure during the first days of life and may reflect compensatory mechanisms that dynamically elevate lung volume in infants with poor lung compliance. • This study has implications for the standardisation of the methodology to apply respiratory oscillometry in preterm infants.