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

Abstract

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).