Electrical Impedance Tomography for Identification of Optimal Positive End-expiratory Pressure in Newborn Infants

Evidence-based guidelines on the optimal level of positive end-expiratory pressure (PEEP) in newborn infants on respiratory support do not exist. Furthermore, there is a lack of simple bed-side parameters to guide clinicians towards the optimal PEEP level. Nevertheless, PEEP requires individual adjustment to minimize ventilator induced lung injury (VILI), shorten the duration of mechanical ventilation and reduce respiratory long-term morbidity. Potential techniques to assess optimal PEEP level in infants on respiratory support include electrical impedance tomography (EIT), the forced oscillation technique (FOT) and the saturation oxygenation pressure index (SOPI). EIT is a promising non-invasive technique that provides information on regional changes in lung aeration and ventilation inhomogeneity. FOT is used in mechanically ventilated or spontaneously breathing infants and provides information on reactance (Xrs) and resistance (Rrs) of the respiratory system. SOPI is a score calculated from the PEEP level, the amount of administered oxygen (FiO2) and the infant's peripheral oxyhaemoglobin saturation (SpO2). SOPI provides information on the ventilation to perfusion ratio dependent on the PEEP level. EIT, FOT and SOPI seem promising tools for identification of optimal PEEP in newborn infants on respiratory support. In particular, a combination of information on regional ventilation (by EIT), global lung mechanics (by FOT) and ventilation to perfusion ratio (by SOPI) will improve the understanding of optimal PEEP and may reduce long-term respiratory sequelae. This prospective single-centre observational study is to identify optimal PEEP in infants on respiratory support by measurements of EIT, FOT and SOPI. Measurements are performed once daily during the first three days on respiratory support and are repeated in weekly intervals if the infant remains mechanically ventilated. An additional measurement is planned after extubation.