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ObjectivesTo investigate the impact of a pre-emptive apnoea triggered oxygen response on oxygen saturation (SpO2) targeting following central apnoea in preterm infants.DesignInterventional crossover study of a 12-hour period of automated oxygen control with an apnoea response (AR) module, nested within a crossover study of a 24-hour period of automated oxygen control compared with aggregated data from two flanking 12-hour periods of manual control.SettingNeonatal intensive care unitPatientsPreterm infants receiving non-invasive respiratory support and supplemental oxygen; median (IQR) birth gestation 27 (26–28) weeks, postnatal age 17 (12–23) days.InterventionAutomated oxygen titration with an automated control algorithm modified to include an AR module. Alterations to inspired oxygen concentration (FiO2) were actuated by a motorised blender. Desired SpO2range was 90–94%. Apnoea detection was by capsule pneumography.Main outcome measuresDuration, magnitude and area under the curve (AUC) of SpO2deviations following apnoea; frequency and duration of apnoeic events. Comparisons between periods of manual, automated and automated control with AR module.ResultsIn 60 studies in 35 infants, inclusion of the AR module significantly reduced AUC for SpO2deviations below baseline compared with both automated and manual control (manual: 87.1%±107.6% s, automated: 84.6%±102.8% s, AR module: 79.4%±102.7% s). However, there was a coincident increase in SpO2overshoot (AUC (SpO2>SpO2(onset)); manual: 44.3±99.9% s, automated: 54.7%±103.4% s, AR module: 65.7%±126.2% s).ConclusionAutomated control with a pre-emptive apnoea-triggered FiO2boost resulted in a modest reduction in post-apnoea hypoxaemia, but was followed by a greater SpO2overshoot.Trial registration numberACTRN12616000300471.

ObjectiveTo evaluate the performance of a rapidly responsive adaptive algorithm (VDL1.1) for automated oxygen control in preterm infants with respiratory insufficiency.DesignInterventional cross-over study of a 24-hour period of automated oxygen control compared with aggregated data from two flanking periods of manual control (12 hours each).SettingNeonatal intensive care unit.ParticipantsPreterm infants receiving non-invasive respiratory support and supplemental oxygen; median birth gestation 27 weeks (IQR 26–28) and postnatal age 17 (12–23) days.InterventionAutomated oxygen titration with the VDL1.1 algorithm, with the incoming SpO2signal derived from a standard oximetry probe, and the computed inspired oxygen concentration (FiO2) adjustments actuated by a motorised blender. The desired SpO2range was 90%–94%, with bedside clinicians able to make corrective manual FiO2adjustments at all times.Main outcome measuresTarget range (TR) time (SpO290%–94% or 90%–100% if in air), periods of SpO2deviation, number of manual FiO2adjustments and oxygen requirement were compared between automated and manual control periods.ResultsIn 60 cross-over studies in 35 infants, automated oxygen titration resulted in greater TR time (manual 58 (51–64)% vs automated 81 (72–85)%, p<0.001), less time at both extremes of oxygenation and considerably fewer prolonged hypoxaemic and hyperoxaemic episodes. The algorithm functioned effectively in every infant. Manual FiO2adjustments were infrequent during automated control (0.11 adjustments/hour), and oxygen requirements were similar (manual 28 (25–32)% and automated 26 (24–32)%, p=0.13).ConclusionThe VDL1.1 algorithm was safe and effective in SpO2targeting in preterm infants on non-invasive respiratory support.Trial registration numberACTRN12616000300471.