Effect of automated titration of oxygen on time spent in a prescribed oxygen saturation range in adults in the ICU after cardiac surgery

Objective The objective of this study was to determine whether automated titration of the fraction of inspired oxygen (FiO2) increases the time spent with oxygen saturation (SpO2) within a predetermined target SpO2 range compared with manually adjusted high-flow oxygen therapy in postoperative cardiac surgical patients managed in the intensive care unit (ICU). Design Single-centre, open-label, randomised clinical trial. Setting Tertiary centre ICU. Participants Recently extubated adults following elective cardiac surgery who required supplemental oxygen. Interventions Automatically adjusted FiO2 (using an automated oxygen control system) compared with manual FiO2 titration, until cessation of oxygen therapy, ICU discharge, or 24 h (whichever was sooner). Main outcome measures The primary outcome was the proportion of time receiving oxygen therapy with the SpO2 in a SpO2 target range of 92–96 %. Results Among 65 participants, the percentage of time per patient spent in the target SpO2 range was a median of 97.7 % (interquartile range: 87.9–99.2 %) and 91.3 % (interquartile range: 77.1–96.1 %) in the automated (n = 28) and manual (n = 28) titration groups, respectively. The estimated effect of automated FiO2, compared to manual FiO2 titration, was to increase the percentage of time spent in the target range by a median of 4.8 percentage points (95 % confidence interval: 1.6 to 10.3 percentage points, p = 0.01). Conclusion In patients recently extubated after cardiac surgery, automated FiO2 titration significantly increased time spent in a target SpO2 range of 92–96 % compared to manual FiO2 titration.