Apnoea-triggered increase in fraction of inspired oxygen in preterm infants: a randomised cross-over study

OBJECTIVES: To investigate the impact of a pre-emptive apnoea triggered oxygen response on oxygen saturation (SpO2) targeting following central apnoea in preterm infants. DESIGN: Interventional crossover study of a 12-hour period of automated oxygen control with an apnoea response (AR) module, nested within a crossover study of a 24-hour period of automated oxygen control compared with aggregated data from two flanking 12-hour periods of manual control. SETTING: Neonatal intensive care unit PATIENTS: Preterm infants receiving non-invasive respiratory support and supplemental oxygen; median (IQR) birth gestation 27 (26-28) weeks, postnatal age 17 (12-23) days. INTERVENTION: Automated oxygen titration with an automated control algorithm modified to include an AR module. Alterations to inspired oxygen concentration (FiO2) were actuated by a motorised blender. Desired SpO2 range was 90-94%. Apnoea detection was by capsule pneumography. MAIN OUTCOME MEASURES: Duration, magnitude and area under the curve (AUC) of SpO2 deviations following apnoea; frequency and duration of apnoeic events. Comparisons between periods of manual, automated and automated control with AR module. RESULTS: In 60 studies in 35 infants, inclusion of the AR module significantly reduced AUC for SpO2 deviations below baseline compared with both automated and manual control (manual: 87.1%±107.6% s, automated: 84.6%±102.8% s, AR module: 79.4%±102.7% s). However, there was a coincident increase in SpO2 overshoot (AUC (SpO2>SpO2(onset)); manual: 44.3±99.9% s, automated: 54.7%±103.4% s, AR module: 65.7%±126.2% s). CONCLUSION: Automated control with a pre-emptive apnoea-triggered FiO2 boost resulted in a modest reduction in post-apnoea hypoxaemia, but was followed by a greater SpO2 overshoot. TRIAL REGISTRATION NUMBER: ACTRN12616000300471.