Continuous Application of Closed-Loop FiO2-Control in Extremely Preterm Infants: A Matched Cohort Single-Center Study.

Introduction: Automated or closed-loop FiO2-control (FiO2-c) has been developed to maintain oxygen saturation (SpO2) within a target range more effectively. However, knowledge of the effects of prolonged use of FiO2-c in extremely preterm infants during a more integral part of NICU admission is limited.

Methods: Twenty five extremely preterm infants (gestational age [GA] < 28 weeks) who survived until NICU discharge and received FiO2-c by Predictive Intelligent Control of Oxygenation (PRICO) were matched 1:1 for GA, birthweight, sex and survival to a cohort receiving routine manual FiO2-c. The proportions of time within the SpO2 target range, (severe) hypoxia, hyperoxia, FiO2 and SpO2 for all days and days on supplemental oxygen, for both the whole period and per week, were compared.

Results: Infants in the FiO2-c cohort received the intervention during 98% of the 7-week study period. Overall, with FiO2-c, a small, non-significant increase in time within SpO2 target range was observed: mean difference 0.5% (95% CI [-5.0, 6.0]). However, when requiring supplemental oxygen during the first 2 weeks of life, time within SpO2 target range significantly increased with FiO2-c, while time in hyperoxia decreased: mean differences in Week 1: 9.9% (95% CI [3.1, 16.7]) and -10.2% (95% CI [-17.1, -3.3]); in Week 2: 9.5% (95% CI [1.4, 17.6]) and -9.9% (95% CI [-19.2, -0.2]).

Conclusion: Despite limited overall effect, continuous use of FiO2-c in extremely preterm infants requiring supplemental oxygen was associated with an increased time within the SpO2 target range during the first 2 weeks of life, a critical window for hyperoxia-related diseases.