RT Journal Article SR Electronic T1 Automated control of inspired oxygen fraction in mechanically ventilated patients: A study protocol for a single-centre randomised controlled trial JF BMJ Open JO BMJ Open FD British Medical Journal Publishing Group SP e089450 DO 10.1136/bmjopen-2024-089450 VO 15 IS 5 A1 Eimer, Christine A1 Selpien, Helene A1 Bastian, Tatiana A1 Hartmann, Lara A1 Sablewski, Armin A1 Lindner, Matthias A1 Becher, Tobias A1 Schädler, Dirk YR 2025 UL http://bmjopen.bmj.com/content/15/5/e089450.abstract AB Background A novel automated system for the control of the inspired fraction of oxygen, named LeoClac, has been implemented on a mechanical ventilator. The system uses a separate sensor for the measurement of peripheral oxygen saturation which is connected directly to the ventilator. We hypothesise that LeoClac will be superior to manual control in keeping critically ill and mechanically ventilated patients in a SpO2-target range (93–96%).Methods This is a randomised controlled, single-centre superiority study with two parallel groups including 40 patients. Mechanically ventilated patients treated on the intensive care unit (ICU) will be screened for eligibility and included in the study after written informed consent. Patients in the intervention group will be treated with LeoClac. In the control group, FiO2 will be controlled manually by the intensive care team. The primary endpoint of the study is the proportion of time in the target zone for peripheral oxygen saturation within the first 24 hours following randomisation. Secondary endpoints include the analysis of hyperoxia and hypoxia, number of changes in FiO2, number and reasons for self-aborts and manual overrides of the automated system, proportion of time in target zone for peripheral oxygen saturation in the subgroups of patients with hypoxemic respiratory failure and acute hypercapnic respiratory failure. Furthermore, ventilator-free days and ICU mortality at day 28 will be analysed.Analysis The precise control of FiO2 with the aim of avoiding both hyperoxia and hypoxia is a fundamental challenge in the highly technical field of mechanical ventilation. Incorporation of patient heterogeneity, the benefits of reduced manual intervention and the potential to optimise treatment outcomes underscore the importance of this research. By addressing the complexities of precise oxygen control in adults, this study contributes to the advancement of critical care practices and may improve patient outcomes.Ethics The study protocol was approved by the ethics committee of the Christian-Albrechts-University Kiel, Germany, on 17 May 2023.Trial registration number DRKS00032113.