Distribution of lung ventilation in spontaneously breathing neonates lying in different body positions

Abstract

The study identified the significant effect of breathing pattern and posture on the spatial distribution of lung ventilation in spontaneously breathing neonates. The results demonstrate that changes in regional ventilation can easily be determined by EIT and bode well for the future use of this method in paediatric intensive care.

Effect of time and body position on ventilation in premature infants

“…In the infants on CPAP, there was also increased regional impedance amplitude in the right lung after 2 h. This phenomenon of increased ventilation in the right lung has previously been reported in premature infants (9,13,14) and it has been suggested that it may be the result of an anatomical structure wherein the right main bronchus is straighter than the left (14) and that there is less lung tissue in the left hemi-thorax (9). EEL in spontaneously breathing preterm infants is maintained above passive resting volume through a combination of mechanisms which include braking of the expiratory flow to prolong the time constant of the respiratory system, decreasing the expiratory time by increasing respiratory rate, and using respiratory muscle activity to dynamically elevate EEL (30,31).…”

“…A cut-off mask of 20% of the peak impedance signal was applied (37). As the preterm infant often displays a periodic respiratory pattern, noise-free, regular sections of data were selected for analysis (9). Data was further analyzed off-line using Matlab 7.1 (The MathWorks, Natick, MA).…”

“…Additionally, modifying positions in preterm infants instantaneously alters regional ventilation distribution (9). However, the changing of positions and handling during cares are also causes of physiological stress (10,11).…”

Changes in lung volume and ventilation following transition from invasive to noninvasive respiratory support and prone positioning in preterm infants

“…It has been suggested that this pattern only applies to sedated and mechanically ventilated infants. In spontaneously breathing infants, ventilation is distributed much more evenly throughout the lung (28,29). Our study showed that application of CDP via the endotracheal or nasal route did not impact ventilation distribution in these spontaneously breathing preterm infants.…”

“…The paradigm that ventilation distribution in infants follows a reversed pattern compared to adults with a preferable distribution to the nondependent (uppermost) lung has recently been challenged (28)(29)(30)(31). It has been suggested that this pattern only applies to sedated and mechanically ventilated infants.…”