Intensive care unit randomised trial comparing two approaches to oxygen therapy (ICU-ROX): results of the pilot phase.

OBJECTIVE The objective of the intensive care unit randomised trial comparing two approaches to oxygen therapy (ICU-ROX) pilot phase, which included the first 100 patients of an overall sample of 1000, was to examine feasibility. DESIGN Investigator-initiated, prospective, parallel-group, pilot randomised controlled trial. SETTING Six medical-surgical intensive care units (ICUs) in Australia and New Zealand, with participants recruited from September 2015 through June 2016. PARTICIPANTS 100 patients ≥ 18 years of age who required invasive mechanical ventilation in the ICU and were expected to be receiving it beyond the next calendar day at the time of randomisation. INTERVENTIONS Conservative oxygen therapy or standard care. MAIN OUTCOME MEASURES Eligibility, recruitment rate, and separation in oxygen exposure (fraction of inspired oxygen [FiO2] and oxygen saturation measured by pulse oximetry [SpO2Z]). RESULTS 94 of 99 participants (94.9%) were confirmed by study monitors to fulfil the study eligibility criteria. 3.6 patients per site per month were enrolled (95% confidence interval [CI], 2.5-4.7). Patients allocated to conservative oxygen therapy spent significantly more time on an FiO2 of 0.21 in the ICU; median, 31.5 hours (interquartile range [IQR], 7-63.5) for conservative oxygen therapy patients v 0 hours for standard oxygen therapy patients (IQR, 0-10; midpoint difference, 21.5 hours; 95% CI, 9-34; P < 0.0001). Patients allocated to conservative oxygen therapy spent less time in the ICU with an SpO2Z of ≥ 97% than patients allocated to standard oxygen therapy; median, 18.5 hours (IQR, 5-46) for conservative oxygen therapy patients v 32 hours for standard oxygen therapy (IQR, 17-80; midpoint difference, 13.5 hours; 95% CI, 2-25; P = 0.02). CONCLUSIONS Our findings confirm the feasibility of completing the ICU-ROX trial without the need for substantive changes to the study protocol for the remaining 900 trial participants. TRIAL REGISTRATION Australian and New Zealand Clinical Trials Registry (ANZCTRN 12615000957594).