Effects of a new device for automated closed loop control of inspired oxygen concentration on fluctuations of arterial and different regional organ tissue oxygen saturations in preterm infants

Arch Dis Child Fetal Neonatal Ed. 2019 Jul;104(4):F360-F365. doi: 10.1136/archdischild-2018-314769. Epub 2018 Aug 28.


Objective: To assess the efficacy of a newly developed system for closed loop control of the fraction of inspired oxygen (FiO2) on variation of arterial (SpO2) and on regional tissue oxygen saturation (StO2) in preterm infants with fluctuations in SpO2.

Design: Randomised crossover trial comparing automated (auto) to manual FiO2 adjustment (manual) during two consecutive 24 hours periods using a Sophie infant ventilator (SPO2C).

Setting: Tertiary university medical centre.

Patients: Twelve very low birthweight infant (VLBWI) (gestational age (median; IQR): (25; 23-26 weeks); birth weight (mean±SD): (667±134 g); postnatal age (mean±SD): (31.5±14 days)).

Main outcome measure: Time within SpO2 target range.

Results: There was an increase in time within the intended SpO2 target range (88%-96%) during auto as compared with manual mode (77.8%±7.1% vs 68.5%±7.7% (mean±SD), p<0.001) and a decrease in time below the SpO2 target during the auto period (18.1%±6.4% vs 25.6%±7.6%; p<0.01). There was a dramatic reduction in events with an SpO2 <88% with >180 s duration: (2 (0-10) vs 10 (0-37) events, p<0.001) and the need for manual adjustments. The time the infants spent above the intended arterial oxygen range (4.1%±3.8% vs 5.9%±3.6%), median FiO2, mean SpO2 over time and StO2 in the brain, liver and kidney did not differ significantly between the two periods.

Conclusions: Closed-loop FiO2 using SPO2C significantly increased time of arterial SpO2 within the intended range in VLBWI and decreased the need for manual adjustments when compared with the routine adjustment by staff members. StO2 was not significantly affected by the mode of oxygen control.

Keywords: closed loop, oxygen, BPD; neonatology.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Cross-Over Studies
  • Female
  • Humans
  • Hypoxia, Brain / therapy*
  • Infant, Premature, Diseases / therapy*
  • Infant, Very Low Birth Weight*
  • Intensive Care Units, Neonatal
  • Male
  • Oxygen / therapeutic use*
  • Oxygen Inhalation Therapy / instrumentation*
  • Respiration, Artificial / methods*


  • Oxygen