Tidal breath in healthy term newborns: An analysis from the 2nd to the 30th days of life.

BACKGROUND Few data are available concerning normative lung function parameters measured in unsedated neonates. AIM To evaluate lung function changes in neonates. METHODS In this prospective cohort study, tidal breath parameters were measured using the MasterScreen PAED system and standardized protocols. Measurements were performed on 60 (30 male) term, healthy, unsedated neonates on the postnatal 2nd and 30th days. RESULTS Expiratory time (TE; p < .001; Cohen's d = 0.561), exhaled volume to peak tidal expiratory flow (VPTEF; p < .001; Cohen's d = 0.789), minute ventilation (p < .001; Cohen's d = 0.926), tidal volume (VT; p < .001; Cohen's d = 1.835), expiratory flow when 75%, 50%, and 25% of tidal volume remaining in the lungs (TEF75 [p < .001; Cohen's d = 1.070], TEF50 [p < .001; Cohen's d = 0.824], TEF25 [p < .001; Cohen's d = 0.568]), and inspiratory time (Ti; p < .001; Cohen's d = 0.654) were higher on Day 30 compared to Day 2, while time to reach peak tidal expiratory flow to total expiratory time (TPTEF/TE; p = .006; Cohen's d = 0.371), the volume until peak tidal expiratory flow to total expiratory volume (VPTEF/VE; p = .001; Cohen's d = 0.447), and respiration rate (RR; p = .001; Cohen's d = 0.432) were lower, and Ti/TE was unchanged. Positive correlation was observed between length and VT (r = .347; p = .008) on Day 2 and (r = .338; p = .008) on Day 30. CONCLUSIONS The present study reveals the physiological changes occurring in lung functions in healthy term neonates during the neonatal period.