Article Text

Download PDFPDF
Randomised cross-over study of automated oxygen control for preterm infants receiving nasal high flow
  1. Peter R Reynolds1,2,
  2. Thomas L Miller3,4,
  3. Leonithas I Volakis5,
  4. Nicky Holland1,
  5. George C Dungan5,6,
  6. Charles Christoph Roehr7,8,
  7. Kevin Ives7
  1. 1 Neonatal Intensive Care Unit, Ashford and St Peter’s Hospitals NHS Foundation Trust, Chertsey, Surrey, UK
  2. 2 School of Biological Sciences, Royal Holloway University of London, Egham, UK
  3. 3 Sidney Kimmel Medical College, Philadelphia, Pennsylvania, USA
  4. 4 Vixiar Medical, Baltimore, Massachusetts, USA
  5. 5 Vapotherm, Exeter, New Hampshire, USA
  6. 6 Canisius College, Buffalo, New York, USA
  7. 7 Oxford University Hospitals NHS Foundation Trust, Oxford, UK
  8. 8 Medical Sciences Division, Department of Paediatrics, University of Oxford, Oxford, UK
  1. Correspondence to Dr. Peter R Reynolds, Neonatal Intensive Care Unit, Ashford and St Peter’s Hospitals NHS Foundation Trust, Chertsey KT16 0PZ, UK; peter.reynolds1{at}


Objective To evaluate a prototype automated controller (IntellO2) of the inspired fraction of oxygen (FiO2) in maintaining a target range of oxygen saturation (SpO2) in preterm babies receiving nasal high flow (HF) via the Vapotherm Precision Flow.

Design Prospective two-centre order-randomised cross-over study.

Setting Neonatal intensive care units.

Patients Preterm infants receiving HF with FiO2 ≥25%.

Intervention Automated versus manual control of FiO2 to maintain a target SpO2 range of 90%–95% (or 90%–100% if FiO2=21%).

Main outcome measures The primary outcome measure was per cent of time spent within target SpO2 range. Secondary outcomes included the overall proportion and durations of SpO2 within specified hyperoxic and hypoxic ranges and the number of in-range episodes per hour.

Results Data were analysed from 30 preterm infants with median (IQR) gestation at birth of 26 (24–27) weeks, study age of 29 (18–53) days and study weight 1080 (959–1443) g. The target SpO2 range was achieved 80% of the time on automated (IntellO2) control (IQR 70%–87%) compared with 49% under manual control (IQR 40%–57%; p<0.0001). There were fewer episodes of SpO2 below 80% lasting at least 60 s under automated control (0 (IQR 0–1.25)) compared with manual control (5 (IQR 2.75–14)). There were no differences in the number of episodes per hour of SpO2 above 98% (4.5 (IQR 1.8–8.5) vs 5.5 (IQR 1.9–14); p=0.572) between the study arms.

Conclusions The IntellO2 automated oxygen controller maintained patients in the target SpO2 range significantly better than manual adjustments in preterm babies receiving HF.

Trial registration number NCT02074774.

  • automatic oxygen control
  • closed loop; IntellO2
  • neonatal intensive care
  • blood oxygen saturation
  • preterm babies
  • high flow
  • high flow nasal cannula
  • monitoring

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Funding This study was sponsored by Vapotherm, Exeter, NH.

  • Competing interests PRR and KI have received travel support and undertaken consulting work for Vapotherm. TLM, LIV and GCD were employees of Vapotherm during the study. NH and CCR have no declarations.

  • Patient consent Written parental consent was obtained for every study participant

  • Ethics approval MHRA Devices Division and Research Ethics Committee (London-Chelsea 16/LO/1272).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement We are happy to share aggregated data; individual data are not made available to ensure that individual subjects cannot be identified.

Linked Articles