Evaluating the effects of two approaches to oxygen therapy in Intensive Care Unit patients requiring life support (mechanical ventilation)

The ‘intervention arm’ is a conservative approach to oxygen therapy, which aims to minimise unnecessary exposure to hyperoxaemia and reduce the exposure to higher than necessary inspired oxygen concentrations. When a participant is allocated to conservative oxygen therapy, the inspired oxygen concentration will be decreased to room air as rapidly as possible provided that the SpO2 measured by peripheral pulse oximetry is greater than the acceptable lower limit. SpO2 levels of greater than 96% will be strictly avoided and an upper SpO2 alarm limit of 97% will apply whenever supplemental oxygen is being administered in the ICU to minimise the risk of hyperoxaemia. After extubation, in the conservative oxygen group, the upper monitored alarm limit of acceptable SpO2 of 97% will still apply whenever supplemental oxygen is being administered. In the event that the SpO2 exceeds the acceptable upper limit, downward titration of supplemental oxygen will be undertaken as a high priority and supplemental oxygen will be discontinued as soon possible. The lower limit alarm for SpO2 will be set at 90% (or lower if clinically appropriate). If the PaO2 or the SaO2 is lower than the acceptable limit, inspired oxygen may be increased if clinically appropriate, irrespective of the SpO2 reading. The intervention will be applied whenever the patient is in the ICU (including any periods of ICU readmission). The duration of the intervention period is until 28 days or hospital discharge, whichever occurs first. The site principal investigators will take primary responsibility for training local staff and will use study tools provided by the coordinating centre including posters describing the intervention. On-site monitoring will be performed by a project manger from the coordinating centre to ensure compliance with the protocol.