Automatic Versus Manual Oxygen Titration Using a Novel Nasal High-flow Device in Medical Inpatients with an Acute Illness: a Randomised Controlled Trial

Background: Guideline recommendations state oxygen should be administered to acutely unwell patients to achieve a target oxygen saturation (SpO) range. The current practice of manual oxygen titration frequently results in SpO outside of a prescribed range. The aim of this study was to assess the efficacy of automatic oxygen titration using a closed-loop feedback system to achieve SpO within a prescribed target range METHODS: An open-label randomised parallel group trial was undertaken comparing automatic oxygen titration using a novel nasal high-flow device to manual oxygen titration using nasal high flow. Medical inpatients requiring oxygen therapy in Wellington Regional Hospital, New Zealand with a prescribed target SpO range of 88%-92% or 92%-96% were recruited and randomised equally between the interventions for a period of 24 hours. The primary outcome was the proportion of time spent with SpO within the prescribed range.

Results: 20 patients were included in the analysis. Automatic oxygen titration resulted in a median (IQR) 96.2% (95.2-97.8) of time within the target range compared with 71% (59.4-88.3) with manual titration; difference (95% CI) 24.2% (7.9% to 35%), p<0.001. There was a reduction in the time spent with SpO ≥2% above and ≥2% below range in the automatic titration group, although the point estimate for the differences were small; -1% (-8.2% to -0.04%), p=0.017 and -2.4% (-11.5% to 0.3%), p=0.05 respectively.

Conclusions: Nasal high-flow with automatic oxygen titration resulted in a greater proportion of time spent with SpO in target range compared with manual titration.

Trial Registration: The trial was registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12619000901101).