BACKGROUND: Peripheral oxygen saturation (SpO METHODS: Oxy-PICU was a pragmatic, multicentre, open-label, randomised controlled trial in England and Scotland. Eligible children were older than 38 weeks and younger than 16 years and had been admitted for emergency care in one of 15 participating PICUs, where they received invasive respiratory support for abnormal gas exchange. Participants were randomly assigned (1:1) to either a conservative oxygenation target (SpO FINDINGS: 2040 children were enrolled between Sept 1, 2020 and May 15, 2022. 1868 (91·6%) children were included in the 90-day survival analysis
of these 930 (49·8%) had been assigned liberal oxygen and 938 (50·2%) conservative oxygen. 1867 (91·5%) children were included in the 1-year survival analysis
930 (49·8%) had been assigned liberal oxygenation and 937 (50·2%) conservative oxygen. At 90 days, 35 (3·7%) patients in the conservative oxygenation group and 45 (4·8%) patients in the liberal oxygenation group had died (adjusted hazard ratio [aHR] 0·75 [95% CI 0·48 to 1·17]). By 1 year, 52 (5·5%) patients in the conservative oxygenation group and 66 (7·1%) patients in the liberal oxygenation group had died (aHR 0·77 [95%CI 0·53 to 1·10]). Overall, mean HRQoL, life-years, and QALYs at 1 year were similar in the two groups. The adjusted incremental effect on cost of conservative oxygenation versus liberal oxygenation was -£879 (95% CI -9036 to 7278), whereas the incremental difference in QALYs was estimated at 0·002 (-0·010 to 0·011), leading to an incremental net monetary benefit of £894 (-7290 to 9078) associated with conservative oxygenation relative to liberal oxygenation. These results did not vary by age (<
12 months vs ≥12 months), comorbidity at baseline, age-adjusted heart rate, or haemoglobin level at admission and were robust to alternative assumptions. INTERPRETATION: Compared with usual care (SpO FUNDING: UK National Institute for Health and Social Care Research Health Technology Assessment Programme.