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.