Hylke Salverda

Abstract Objective To compare the effect of two different automated oxygen control devices on target range (TR) time and occurrence of hypoxaemic and hyperoxaemic episodes. Design Randomised cross-over study. Setting Tertiary level neonatal unit in the Netherlands Patients Preterm infants (n=15) born between 24+0-29+6 days of gestation, receiving invasive or non-invasive respiratory support with oxygen saturation (SpO2) TR of 91% - 95% . Median gestational age 26 weeks and 4 days (IQR 25 weeks 3 days-27 weeks 6 days) and post-natal age 19 (IQR 17-24) days. Interventions Inspired oxygen concentration was titrated by the OxyGenie controller (SLE6000 ventilator) and the CLiO2 controller (AVEA ventilator) for 24 hours each, in a random sequence, with the respiratory support mode kept constant. Main outcome measures Time spent within set SpO2 TR (91%-95% with supplemental oxygen, or 91%-100% without supplemental oxygen) Results Time spent within the SpO2 TR was higher during OxyGenie control (80.2 (72.6–82.4)% vs 68.5 (56.7–79.3)%, p<0.005). Less time was spent above TR while in supplemental oxygen (6.3 (5.1-9.9)% vs 15.9 (11.5-30.7)%, p<0.005) but more time spent below TR during OxyGenie control (14.7 (11.8-17.2%) vs 9.3(8.2-12.6)%, p<0.05). There was no significant difference in time with SpO2<80% (0.5 (0.1-1.0)% vs 0.2 (0.1-0.4)%, p=0.061). Long-lasting SpO2 deviations occurred less frequently during OxyGenie control. Conclusions The OxyGenie control algorithm was more effective in keeping the oxygen saturation within target range and preventing hyperoxaemia, and equally effective in preventing hypoxaemia (SpO2<80%), albeit at the cost of a small increase in mild hypoxaemia. Keywords: Hypoxemia; hyperoxia; closed-loop; algorithm; neonate