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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.