Background: The balance of risks and benefits of conservative v standard care oxygen strategies for patients who are invasively ventilated in the intensive care unit (ICU) is uncertain.
Objective: To describe the study protocol and statistical analysis plan for the ICU randomised trial comparing two approaches to oxygen therapy (ICU-ROX).
Design, setting and participants: Protocol for a multicentre, randomised, participant and outcome assessor-blinded, standard care-controlled, parallel-group, two-sided superiority trial to be conducted in up to 22 ICUs in Australia and New Zealand. 1000 adults who are mechanically ventilated in the ICU and expected to remain ventilated beyond the day after recruitment will be randomly assigned to conservative oxygen therapy or standard care in a 1:1 ratio. ICU-ROX began with an internal pilot phase in September 2015. It is anticipated that recruitment will be completed in 2018.
Main outcome measures: The primary endpoint will be alive, ventilator-free days to Day 28. Secondary outcomes include 90- and 180-day all-cause mortality, survival time to 180 days, and quality of life and cognitive function at 180 days. All analyses will be conducted on an intentionto- treat basis.
Results and conclusions: ICU-ROX will compare the effect of conservative v standard oxygen therapy in critically ill mechanically ventilated adults who are expected to be ventilated beyond the day after recruitment on ventilatorfree days to Day 28.
Trial registration: Australian and New Zealand Clinical Trials Registry (ANZCTRN 12615000957594).