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 (FiO) increases the time spent with oxygen saturation (SpO) within a predetermined target SpO 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 FiO (using an automated oxygen control system) compared with manual FiO 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 SpO in a SpO target range of 92-96 %.

Results: Among 65 participants, the percentage of time per patient spent in the target SpO 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 FiO, compared to manual FiO 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 FiO titration significantly increased time spent in a target SpO range of 92-96 % compared to manual FiO titration.