Objective To evaluate the performance of a rapidly responsive adaptive algorithm (VDL1.1) for automated oxygen control in preterm infants with respiratory insufficiency.
Design Interventional 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).
Setting Neonatal intensive care unit.
Participants Preterm infants receiving non-invasive respiratory support and supplemental oxygen; median birth gestation 27 weeks (IQR 26–28) and postnatal age 17 (12–23) days.
Intervention Automated oxygen titration with the VDL1.1 algorithm, with the incoming SpO2 signal derived from a standard oximetry probe, and the computed inspired oxygen concentration (FiO2) adjustments actuated by a motorised blender. The desired SpO2 range was 90%–94%, with bedside clinicians able to make corrective manual FiO2 adjustments at all times.
Main outcome measures Target range (TR) time (SpO2 90%–94% or 90%–100% if in air), periods of SpO2 deviation, number of manual FiO2 adjustments and oxygen requirement were compared between automated and manual control periods.
Results In 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 FiO2 adjustments 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).
Conclusion The VDL1.1 algorithm was safe and effective in SpO2 targeting in preterm infants on non-invasive respiratory support.
Trial registration number ACTRN12616000300471.
Data availability statement
Data are available upon reasonable request.
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Contributors PAD: conceived the algorithm (with TJG) and this study, oversaw its conduct, compiled and analysed the data, wrote the first draft of the manuscript, and approved the final version. AM: conceived and developed the study equipment, assisted in conducting the study, compiled and analysed the data, edited the manuscript and approved the final version. OJL, CB and SKMA: assisted with the study conduct, reviewed and edited the manuscript, and approved the final version. RJ: identified enhancements to the automated control algorithm, reviewed and edited the manuscript, and approved the final version. CE-S: assisted in developing the study equipment, edited the manuscript and approved the final version. KL: compiled and analysed the data, edited the manuscript and approved the final version. TJG: conceived the algorithm (with PAD) and this study, oversaw its conduct, reviewed and edited the manuscript, and approved the final version.
Funding This work was supported by Royal Hobart Hospital Research Foundation (grant number 15-203).
Competing interests The University of Tasmania and Tasmanian Health Service have jointly lodged a patent application concerning automated control of inspired oxygen concentration in the newborn infant, and have entered into a licensing agreement with SLE Limited allowing use of the VDL1.1 algorithm (as OxyGenie) in SLE respiratory support devices.
Provenance and peer review Not commissioned; externally peer reviewed.
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