Lung function by tidal breathing in awake healthy newborn infants

Area of Science:

• Neonatal Physiology
• Pediatric Respiratory Medicine
• Clinical Research

Background:

• Increasing availability of infant lung function measurement devices.
• Need for established reference values for clinical and epidemiological applications in newborns.
• Limited data on factors influencing lung function variability in healthy awake infants.

Purpose of the Study:

• To establish reference values for tidal breathing lung function in awake newborn infants.
• To investigate potential sources of variability in infant lung function measurements.

Main Methods:

• Measurement of tidal flow-volume loops in 803 awake, healthy infants.
• Assessment of passive respiratory mechanics using the single-breath occlusion technique in 664 infants.
• Analysis of data considering postnatal age, gestational age, birthweight, and gender.

Main Results:

• Tidal expiratory volume (Vt), peak tidal expiratory flow (PEF), and mid-expiratory flow increased with birthweight.
• Flow ratios were highest in 1-day-old infants, decreasing by day 4-5, independent of birthweight.
• Tidal flows and flow ratios were higher in males than females, even after weight adjustment. Respiratory rates correlated with tidal flows and inversely with Vt.

Conclusions:

• Infant lung function, including tidal breathing parameters, demonstrates significant variability.
• Birthweight, gender, and postnatal age are key factors influencing lung function in healthy awake infants.
• Established reference values are essential for accurate interpretation of infant respiratory assessments.