Automated control of oxygen titration in preterm infants on non-invasive respiratory support

Abstract

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\u2009hours 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. An automated oxygen controller increased the proportion of time that oxygen dependent preterm infants on non-invasive respiratory support spent in their target SpO2 range and reduced their exposure to extremes of SpO2.