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

ABSTRACT

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.