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Reducing oxygen levels for children in intensive care will save lives, new study shows

Published: 02 December 2023

A new landmark NIHR-funded study has found that reducing oxygen levels in critically ill children on mechanical ventilators in intensive care could save tens of young lives each year

It could also reduce the number of days spent on machines supporting organs, saving the NHS £20 million every year.  

Common treatment

In the UK, around 20,000 children are admitted to intensive care each year. Roughly 75% will receive additional oxygen through a ventilator. 

Oxygen is one of the most common treatments used in emergency situations. Doctors and nurses adjust oxygen treatment based on how much oxygen their patient has in their blood. While very low oxygen levels are harmful, current research shows that slightly lower than normal levels may be the best target for very ill people. 

The Oxy-PICU study is the largest randomised controlled trial ever conducted in paediatric intensive care units (PICUs). It was led by researchers from:

  • Great Ormond Street Hospital (GOSH)
  • University College London (UCL)
  • the Intensive Care National Audit & Research Centre (ICNARC)
  • the Paediatric Critical Care Society Study Group (PCCS-SG) 

The researchers recruited 2,040 children from 15 NHS PICUs across England and Scotland. Each of the children required a mechanical ventilator and extra oxygen on admission to the PICU.

The children, who ranged from newborn up to 16 years, were randomly allocated to one of two groups. They received either: 

  • oxygen to the standard target level (saturation “SpO2” >94%) 
  • or a reduced oxygen target (SpO2 88-92%)

The percentages refer to the proportion of the oxygen-carrying capacity of the blood that is being used.

Wide-ranging benefit

The researchers found that the children who received the lower level of oxygen were 6% more likely to have a better outcome, either in terms of survival or the number of days spent on machines supporting their organs.

If the approach was scaled up across the NHS, it could save 50 lives, 6,000 ICU bed days and £20 million annually in the UK alone. The findings have been published in The Lancet

The Oxy-PICU study is funded by the NIHR’s Health Technology Assessment programme and supported by the NIHR’s Biomedical Research Centres at GOSH and UCLH.

Professor Mark Peters, Consultant Paediatric Intensivist at GOSH and Professor of Paediatric Intensive Care at UCL Great Ormond St Institute of Child Health, and lead author on the study, said: “Giving the minimum safe dose of anything in intensive care appears to generate the best outcomes, so we wanted to test this approach with oxygen. 

“We found a small benefit of lower oxygen targets that is unlikely to have been due to chance. But because so many children are treated with oxygen, this has the potential to improve outcomes and reduce healthcare costs in the UK and around the world. This could have particular implications in countries where oxygen is a scarce resource, or in situations as we have seen in recent years, where health needs change, and oxygen demand quickly peaks.”

Cross-country collaboration

Lauran O’Neill, Senior Critical Care Research Nurse at GOSH, said: “This is a major milestone study, which was nurse-led, with research taking place at the bedside as part of normal clinical care. It’s a great example of a research-hospital vision as every child admitted to ICU was screened for inclusion into the study.

“Although GOSH teams were managing the study and a major recruiter, undertaking the research process was part of the standard of care for many emergency teams across the country - so training and education was the focus. We had to work well together across all collaborating hospitals to deliver this huge success for our patients.”

Professor Marian Knight, Scientific Director for NIHR Infrastructure, said: “The purpose of all NIHR health and care research is to save or improve lives in some way, whether by questioning what we currently do or introducing new practice. 

"This landmark nurse-led study has challenged the accepted practice for providing oxygen to children in intensive care in a way that could have a global impact. We are proud to have supported Prof Peters and his team through both our Health Technology Assessment programme, our Biomedical Research Centre at GOSH, and with our remarkable NIHR research nursing staff.”

The Oxy-PICU paper has been published by The Lancet.

Participating hospitals

  • Alder Hey Children’s Hospital, Alder Hey Children’s NHS Foundation Trust
  • Birmingham Children's Hospital, Birmingham Women’s and Children’s NHS Foundation Trust
  • Bristol Royal Hospital, University Hospitals Bristol and Weston NHS Foundation Trust
  • Children’s Acute Transport Service, Great Ormond Street Hospital NHS Trust
  • Evelina London, Guy’s and St Thomas’s Hospital NHS Trust
  • Great Ormond Street, Great Ormond Street Hospital
  • John Radcliffe Hospital, Oxford University Hospitals NHS Foundation Trust
  • King’s College Hospital, London, King’s College Hospital NHS Foundation Trust
  • Leicester Children’s Hospital, University Hospitals of Leicester NHS Trust
  • Nottingham Children’s Hospital, Nottingham University Hospitals NHS Trust
  • Royal Hospital for Children, Greater Glasgow and Clyde
  • Royal Manchester Children’s Hospital, Manchester NHS Foundation Trust
  • Southampton General Hospital, University Hospital Southampton NHS Foundation Trust
  • St George’s University Hospital, St George’s University Hospitals NHS Foundation Trust
  • St Mary’s Hospital, Imperial College NHS Trust
  • The Great North Children’s Hospital, The Newcastle Upon Tyne Hospitals NHS Foundation Trust

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