Hylke Salverda

139 8 Clinical outcomes comparison of two different AOCs Introduction Very preterm infants undergo a long undertaking from birth to discharge from the hospital out of which few arise unscathed. Four in ten of these infants experience a serious adverse outcome such as in-hospital mortality, bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP) requiring treatment or severe neurologic injury.1 As demonstrated by a post-hoc analysis of the data from NeOProM metaanalysis, these outcomes are likely to be at least partly affected by the degree of success in targeting a specific oxygen saturation range (SpO2 TR). 2, 3 Targeting the SpO2 TR is done by carefully titrating the administered supplemental oxygenduring respiratory support, eithermanually by bedside staffor by an automated oxygen controller (AOC). There are currentlymultiple systems commercially available for automated titration of the supplied oxygen.4-9 All current evidence points towards more overall success for AOCs on achieved time within the SpO2 TR. However, the available controllers employ different algorithms10 and it is unclearwhich of these algorithms lead to better long and short-term outcome. The one algorithm X may on average keep oxygen saturation higher and have fewer desaturations at the cost of more hyperoxaemia; whereas the other algorithm Y may adhere better to the defined oxygen saturation limits at the cost of more short but frequent desaturations. Both the increase in hyperoxaemia with algorithm X could increase the risk for ROP, and the higher incidence of intermittent hypoxaemia with algorithm Y could yield similar effects.11, 12 Furthermore, the amplitude of SpO 2 fluctuations and the duration of the episodes will most likely also be a factor of influence. Both factors can be influenced by choice of algorithm, for example by algorithm design, pulseoximeter settings and choice of SpO2 TR. A similar conundrum may exist for BPD, neurodevelopmental and other long-term outcomes.12, 13 Studies comparing these clinical outcomes for different AOCs are lacking. Two controllers employing distinctly different algorithms, the CLiO2 algorithm implemented in the AVEA ventilator (Vyaire, Yorba Linda, California, USA) and the OxyGenie algorithm (VDL 1.1) embedded in the SLE6000 ventilator (SLE Limited, South Croydon, UK) were used in the neonatal unit of Leiden University Medical Center (LUMC). Both algorithms have been described in detail in a recent publication.10 We recently demonstrated that the OxyGenie algorithm was more effective in keeping SpO2 within the SpO2 TR, preventing hyperoxaemia, and just as effective in preventing hypoxaemia. While using the CLiO2 algorithm there was less time spent in the SpO2 range of 80%-90%, possibly due to the lower median