Hylke Salverda

123 7 AOC for very preterm infants and neurodevelopmental outcome at two years Introduction Maintaining appropriate oxygenation in preterm infants admitted to the Neonatal Intensive Care Unit (NICU) has proved challenging but of importance to outcome. Neonatal morbidity and mortality are linked to hypoxemia, hyperoxaemia and choice of SpO2 target range. 1-3 Post-hoc analysis of the Canadian Oxygen Trial data associated adverse neurodevelopmental outcome with hypoxia, in particular hypoxic episodes lasting more than 1 minute.4 Hunt et al. reported similar evidence in their report of home-monitored preterm and term infants: having five or more apneic/ bradycardic events was associated with a 5.6 point lower mental development index.5 Neither study showed a significant difference for episodes under 1 minute. These results could indicate that faster resolution of hypoxaemic or hyperoxaemic events may reduce long-term neurodevelopmental impairment (NDI). Automatic titration of inspired oxygen (FiO2) can provide a more prompt response to these events than when titration is done manually by bedside staff. With the aim of keeping SpO2 in a specified target range, an automated oxygen controller (AOC) built into the respirator continually evaluates on the measured SpO2 and makes changes in FiO2 where necessary. Beside potential benefits to workload, it has been demonstrated that several commercially available controllers increase the time preterm infants spent within the target range while used for 2-24 hour periods, and prolonged episodes of hypoxemia and hyperoxaemia are reduced.6-13 This was also reflected in a study14 done in our centre while using an AOC as standard of care. However, to date evidence on clinically relevant neonatal outcome is scarce,15 and lacking altogether beyond the neonatal period. In August 2015 AOC was implemented as standard of care in the Neonatal Intensive Care Unit (NICU) of the Leiden University Medical Center (LUMC). Recently we reported the effect of this implementation on clinical outcome of preterm infants during admission.15 Implementation did not lead to a change in mortality or rate of retinopathy of prematurity (ROP), necrotising enterocolitis (NEC), intraventricular haemorrhage (IVH), periventricular leukomalacia (PVL), or bronchopulmonary dysplasia (BPD), but there was less invasive ventilation in the post-implementation cohort. Thus far, none of the studies comparing manual oxygen control with AOC have reported the effect on long-term neurodevelopmental outcome. We therefore aimed to compare the neurodevelopmental outcome of preterm infants born before and after the implementation of AOC as standard care with routinely performed two year follow-up assessment.