Written by Seth Walsh-Blackmore
Spoon Feed
A large multicenter RCT found no 90-day mortality difference among intubated ICU patients with an oxygen titration strategy targeting a peripheral saturation (SpO2) of 90% vs. provider discretion.
Some breathing room on the SpO2?
Supplemental oxygen is one of the most common interventions in the ICU. Oxygen may be toxic at prolonged or high doses, so several RCTs have compared administration protocols in the ICU. So far, there has been no clear mortality impact, but also no RCT of this size.1-5
The UK-ROX trial compared a “conservative” oxygen target of SpO2 90% within a range of 88–92% vs. provider discretion in adult ICU patients intubated within 12 hours of enrollment. In both groups, additional therapies were at the provider’s discretion. If extubated to another form of supplemental O2, the oxygen parameter was continued until discharged from the ICU. It analyzed data from 16,434 patients across 97 centers in the United Kingdom, with a loss to follow-up rate of only 0.2%.
The primary outcome of 90-day mortality occurred in 35.4% of patients treated with the conservative protocol versus 34.9% with provider discretion. The adjusted risk difference of 0.7 (95%CI −0.7 to 2.0; P = .28) was not statistically significant. Days free of organ support, ICU, and hospital length of stay lacked significant differences. Total oxygen exposure, measured in 100% FiO2 equivalent hours, was lower in the conservative group (20.3 vs. 28.7 equivalent hours), as was the median FiO2 (0.31 vs. 0.35), and PaO2 (71.5 vs. 79.5 mmHg).
How does this change my practice?
The usual ICU care in the UK appears to be relatively low FiO2 exposure. The ICU-ROX and OXYGEN-ICU trial findings, which showed no benefit and potential harm above an SpO2 of 97%, may have influenced this decision. It may also be impacted by nearly 20% of eligible patients being excluded based on the treating physician’s judgment before randomization. Overall, this very robust study enhances my confidence that a SpO2 goal of 90% or higher is sufficient for many ICU patients, potentially reducing additional interventions and restrictions.
Source
Conservative Oxygen Therapy in Mechanically Ventilated Critically Ill Adult Patients: The UK-ROX Randomized Clinical Trial. JAMA vol. 334,5 (2025): 398-408. doi:10.1001/jama.2025.9663
Works Cited
- ICU-ROX Investigators and the Australian and New Zealand Intensive Care Society Clinical Trials Group et al. Conservative Oxygen Therapy during Mechanical Ventilation in the ICU. The New England journal of medicine vol. 382,11 (2020): 989-998. doi:10.1056/NEJMoa1903297
- Bitterman, Haim. “Bench-to-bedside review: oxygen as a drug.” Critical care (London, England) vol. 13,1 (2009): 205. doi:10.1186/cc7151
- de Jonge, E., Peelen, L., Keijzers, P.J. et al. Association between administered oxygen, arterial partial oxygen pressure and mortality in mechanically ventilated intensive care unit patients. Crit Care 12, R156 (2008). https://doi.org/10.1186/cc7150
- Palmer E, Post B, Klapaukh R, et al. The Association between Supraphysiologic Arterial Oxygen Levels and Mortality in Critically Ill Patients. A Multicenter Observational Cohort Study. Am J Respir Crit Care Med. 2019;200(11):1373-1380. doi:10.1164/rccm.201904-0849OC
- van der Wal, L Imeen et al. Conservative versus Liberal Oxygenation Targets in Intensive Care Unit Patients (ICONIC): A Randomized Clinical Trial. American journal of respiratory and critical care medicine vol. 208,7 (2023): 770-779. doi:10.1164/rccm.202303-0560OC
