Changes in Lung Volume and Ventilation During Apnoea of Prematurity Using EIT

Central Apnoea of prematurity (AoP) is a common complication in preterm infants. AoP impact oxygenation but it is unclear what its effect is on lung volume and ventilation distribution. Electrical Impedance Tomography is a technique able to continuously and bedside monitor lung volume changes in preterm infants.

In a subset of preterm infants of the CRADL project (Continuous Regional Analysis device for neonate Lung) we extracted, using a self-developed automatic detection algorithm and followed by a hand check central AoP, EIT tracings. These EIT tracings were analysed pre-, during and post apnoea for changes in relative end expiratory lung impedance (EELI), tidal volume, breathing rate, minute volume and ventilation distribution.

In 15 preterm infants, 203 apnoeas were identified and included into this study. During apnoeas a significant drop (p < 0.05) in relative EELI was seen but this restored to pre-apnoea levels, mediated by an increased median tidal volume (0.43 AU [0.34-0.57] to 0.57 AU [0.47-0.70], p < 0.05). Ventilation distribution on a regional level (right-left, anterior-posterior or centre of ventilation) showed no changes pre- and post- apnoea.

Central AoP results in a significant decrease in EELI but this restores to pre-apnoea levels by compensatory increased tidal volume. No changes in ventilation distribution were detected after an apnoea.