Effect of body position on ventilation distribution in healthy newborn infants: an observational study

Objectives Newborn infants have unique respiratory physiology compared with older children and adults due to their lungs' structural and functional immaturity and highly compliant chest wall. To date, ventilation distribution has seldom been studied in this age group. This study aims to assess the effect of body position on ventilation distribution in spontaneously breathing healthy neonates.Design Prospective observational study.Setting Maternity wards of Oulu University Hospital.Patients 20 healthy, spontaneously breathing, newborn infants.Interventions Electrical impedance tomography data were recorded with a 32-electrode belt (Sentec AG, Landquart, Switzerland) in six different body positions in random order. Ventilation distribution was retrospectively assessed 10 minutes after each position change.Main outcome measures In each position, regional tidal impedance variation (Delta Z) and ventral-to-dorsal and right-to-left centre of ventilation were measured.Results The mean global Delta Z was the largest in supine position and it was smaller in prone and lateral positions. Yet, global Delta Z did not differ in supine positions, ventilation distribution was more directed towards the non-dependent lung region in supine tilted position (p<0.001). In prone, a reduction of global Delta Z was observed (p<0.05) corresponding to an amount of 10% of global tidal variation in supine position. In both lateral positions, tidal ventilation was distributed more to the corresponding non-dependent lung region.Conclusions Prone or lateral body positioning in healthy spontaneously breathing newborns leads to a redistribution of ventilation to the non-dependent lung regions and at the same time global tidal volume is reduced as compared with supine.